47 files changed, 1124 insertions, 451 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 4412b0708..c06236692 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,9 +2,9 @@
 # It is not intended for manual editing.
 [[package]]
 name = "addr2line"
-version = "0.12.0"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "456d75cbb82da1ad150c8a9d97285ffcd21c9931dcb11e995903e7d75141b38b"
+checksum = "a49806b9dadc843c61e7c97e72490ad7f7220ae249012fbda9ad0609457c0543"
 dependencies = [
  "gimli",
 ]
@@ -20,9 +20,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.29"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc98824304f5513bb8f862f9e5985219003de4d730689e59d8f28818283a6fe4"
+checksum = "85bb70cc08ec97ca5450e6eba421deeea5f172c0fc61f78b5357b2a8e8be195f"
 
 [[package]]
 name = "anymap"
@@ -55,9 +55,9 @@ checksum = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
 
 [[package]]
 name = "backtrace"
-version = "0.3.47"
+version = "0.3.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5393cb2f40a6fae0014c9af00018e95846f3b241b331a6b7733c326d3e58108"
+checksum = "0df2f85c8a2abbe3b7d7e748052fdd9b76a0458fdeb16ad4223f5eca78c7c130"
 dependencies = [
  "addr2line",
  "cfg-if",
@@ -101,9 +101,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.0.52"
+version = "1.0.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3d87b23d6a92cd03af510a5ade527033f6aa6fa92161e2d5863a907d4c5e31d"
+checksum = "404b1fe4f65288577753b17e3b36a04596ee784493ec249bf81c7f2d2acd751c"
 
 [[package]]
 name = "cfg-if"
@@ -360,9 +360,9 @@ checksum = "86d4de0081402f5e88cdac65c8dcdcc73118c1a7a465e2a05f0da05843a8ea33"
 
 [[package]]
 name = "fnv"
-version = "1.0.6"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
 [[package]]
 name = "fs_extra"
@@ -463,9 +463,9 @@ dependencies = [
 
 [[package]]
 name = "hermit-abi"
-version = "0.1.12"
+version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61565ff7aaace3525556587bd2dc31d4a07071957be715e63ce7b1eccf51a8f4"
+checksum = "91780f809e750b0a89f5544be56617ff6b1227ee485bcb06ebe10cdf89bd3b71"
 dependencies = [
  "libc",
 ]
@@ -809,9 +809,9 @@ checksum = "9cbca9424c482ee628fa549d9c812e2cd22f1180b9222c9200fdfa6eb31aecb2"
 
 [[package]]
 name = "once_cell"
-version = "1.3.1"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1c601810575c99596d4afc46f78a678c80105117c379eb3650cf99b8a21ce5b"
+checksum = "0b631f7e854af39a1739f401cf34a8a013dfe09eac4fa4dba91e9768bd28168d"
 
 [[package]]
 name = "ordermap"
@@ -895,9 +895,9 @@ checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
 
 [[package]]
 name = "ppv-lite86"
-version = "0.2.6"
+version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
+checksum = "237a5ed80e274dbc66f86bd59c1e25edc039660be53194b5fe0a482e0f2612ea"
 
 [[package]]
 name = "proc-macro-hack"
@@ -907,18 +907,18 @@ checksum = "0d659fe7c6d27f25e9d80a1a094c223f5246f6a6596453e09d7229bf42750b63"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.12"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8872cf6f48eee44265156c111456a700ab3483686b3f96df4cf5481c89157319"
+checksum = "53f5ffe53a6b28e37c9c1ce74893477864d64f74778a93a4beb43c8fa167f639"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.5"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42934bc9c8ab0d3b273a16d8551c8f0fcff46be73276ca083ec2414c15c4ba5e"
+checksum = "54a21852a652ad6f610c9510194f398ff6f8692e334fd1145fed931f7fbe44ea"
 dependencies = [
  "proc-macro2",
 ]
@@ -1610,9 +1610,9 @@ checksum = "ab16ced94dbd8a46c82fd81e3ed9a8727dac2977ea869d217bcc4ea1f122e81f"
 
 [[package]]
 name = "syn"
-version = "1.0.21"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4696caa4048ac7ce2bcd2e484b3cef88c1004e41b8e945a277e2c25dc0b72060"
+checksum = "1425de3c33b0941002740a420b1a906a350b88d08b82b2c8a01035a3f9447bac"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/crates/ra_assists/src/assist_config.rs b/crates/ra_assists/src/assist_config.rs
new file mode 100644
index 000000000..c0a0226fb
--- /dev/null
+++ b/crates/ra_assists/src/assist_config.rs
@@ -0,0 +1,27 @@
+//! Settings for tweaking assists.
+//!
+//! The fun thing here is `SnippetCap` -- this type can only be created in this
+//! module, and we use to statically check that we only produce snippet
+//! assists if we are allowed to.
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct AssistConfig {
+    pub snippet_cap: Option<SnippetCap>,
+}
+
+impl AssistConfig {
+    pub fn allow_snippets(&mut self, yes: bool) {
+        self.snippet_cap = if yes { Some(SnippetCap { _private: () }) } else { None }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct SnippetCap {
+    _private: (),
+}
+
+impl Default for AssistConfig {
+    fn default() -> Self {
+        AssistConfig { snippet_cap: Some(SnippetCap { _private: () }) }
+    }
+}
diff --git a/crates/ra_assists/src/assist_context.rs b/crates/ra_assists/src/assist_context.rs
index a680f752b..005c17776 100644
--- a/crates/ra_assists/src/assist_context.rs
+++ b/crates/ra_assists/src/assist_context.rs
@@ -15,7 +15,10 @@ use ra_syntax::{
 };
 use ra_text_edit::TextEditBuilder;
 
-use crate::{Assist, AssistId, GroupLabel, ResolvedAssist};
+use crate::{
+    assist_config::{AssistConfig, SnippetCap},
+    Assist, AssistId, GroupLabel, ResolvedAssist,
+};
 
 /// `AssistContext` allows to apply an assist or check if it could be applied.
 ///
@@ -48,6 +51,7 @@ use crate::{Assist, AssistId, GroupLabel, ResolvedAssist};
 /// moment, because the LSP API is pretty awkward in this place, and it's much
 /// easier to just compute the edit eagerly :-)
 pub(crate) struct AssistContext<'a> {
+    pub(crate) config: &'a AssistConfig,
     pub(crate) sema: Semantics<'a, RootDatabase>,
     pub(crate) db: &'a RootDatabase,
     pub(crate) frange: FileRange,
@@ -55,10 +59,14 @@ pub(crate) struct AssistContext<'a> {
 }
 
 impl<'a> AssistContext<'a> {
-    pub fn new(sema: Semantics<'a, RootDatabase>, frange: FileRange) -> AssistContext<'a> {
+    pub(crate) fn new(
+        sema: Semantics<'a, RootDatabase>,
+        config: &'a AssistConfig,
+        frange: FileRange,
+    ) -> AssistContext<'a> {
         let source_file = sema.parse(frange.file_id);
         let db = sema.db;
-        AssistContext { sema, db, frange, source_file }
+        AssistContext { config, sema, db, frange, source_file }
     }
 
     // NB, this ignores active selection.
@@ -165,11 +173,17 @@ pub(crate) struct AssistBuilder {
     edit: TextEditBuilder,
     cursor_position: Option<TextSize>,
     file: FileId,
+    is_snippet: bool,
 }
 
 impl AssistBuilder {
     pub(crate) fn new(file: FileId) -> AssistBuilder {
-        AssistBuilder { edit: TextEditBuilder::default(), cursor_position: None, file }
+        AssistBuilder {
+            edit: TextEditBuilder::default(),
+            cursor_position: None,
+            file,
+            is_snippet: false,
+        }
     }
 
     /// Remove specified `range` of text.
@@ -180,10 +194,30 @@ impl AssistBuilder {
     pub(crate) fn insert(&mut self, offset: TextSize, text: impl Into<String>) {
         self.edit.insert(offset, text.into())
     }
+    /// Append specified `snippet` at the given `offset`
+    pub(crate) fn insert_snippet(
+        &mut self,
+        _cap: SnippetCap,
+        offset: TextSize,
+        snippet: impl Into<String>,
+    ) {
+        self.is_snippet = true;
+        self.insert(offset, snippet);
+    }
     /// Replaces specified `range` of text with a given string.
     pub(crate) fn replace(&mut self, range: TextRange, replace_with: impl Into<String>) {
         self.edit.replace(range, replace_with.into())
     }
+    /// Replaces specified `range` of text with a given `snippet`.
+    pub(crate) fn replace_snippet(
+        &mut self,
+        _cap: SnippetCap,
+        range: TextRange,
+        snippet: impl Into<String>,
+    ) {
+        self.is_snippet = true;
+        self.replace(range, snippet);
+    }
     pub(crate) fn replace_ast<N: AstNode>(&mut self, old: N, new: N) {
         algo::diff(old.syntax(), new.syntax()).into_text_edit(&mut self.edit)
     }
@@ -227,7 +261,12 @@ impl AssistBuilder {
         if edit.is_empty() && self.cursor_position.is_none() {
             panic!("Only call `add_assist` if the assist can be applied")
         }
-        SingleFileChange { label: change_label, edit, cursor_position: self.cursor_position }
-            .into_source_change(self.file)
+        let mut res =
+            SingleFileChange { label: change_label, edit, cursor_position: self.cursor_position }
+                .into_source_change(self.file);
+        if self.is_snippet {
+            res.is_snippet = true;
+        }
+        res
     }
 }
diff --git a/crates/ra_assists/src/handlers/add_custom_impl.rs b/crates/ra_assists/src/handlers/add_custom_impl.rs
index 2baeb8607..fa70c8496 100644
--- a/crates/ra_assists/src/handlers/add_custom_impl.rs
+++ b/crates/ra_assists/src/handlers/add_custom_impl.rs
@@ -25,7 +25,7 @@ use crate::{
 // struct S;
 //
 // impl Debug for S {
-//
+//     $0
 // }
 // ```
 pub(crate) fn add_custom_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
@@ -52,7 +52,7 @@ pub(crate) fn add_custom_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<
         format!("Add custom impl `{}` for `{}`", trait_token.text().as_str(), annotated_name);
 
     let target = attr.syntax().text_range();
-    acc.add(AssistId("add_custom_impl"), label, target, |edit| {
+    acc.add(AssistId("add_custom_impl"), label, target, |builder| {
         let new_attr_input = input
             .syntax()
             .descendants_with_tokens()
@@ -63,20 +63,11 @@ pub(crate) fn add_custom_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<
         let has_more_derives = !new_attr_input.is_empty();
         let new_attr_input = new_attr_input.iter().sep_by(", ").surround_with("(", ")").to_string();
 
-        let mut buf = String::new();
-        buf.push_str("\n\nimpl ");
-        buf.push_str(trait_token.text().as_str());
-        buf.push_str(" for ");
-        buf.push_str(annotated_name.as_str());
-        buf.push_str(" {\n");
-
-        let cursor_delta = if has_more_derives {
-            let delta = input.syntax().text_range().len() - TextSize::of(&new_attr_input);
-            edit.replace(input.syntax().text_range(), new_attr_input);
-            delta
+        if has_more_derives {
+            builder.replace(input.syntax().text_range(), new_attr_input);
         } else {
             let attr_range = attr.syntax().text_range();
-            edit.delete(attr_range);
+            builder.delete(attr_range);
 
             let line_break_range = attr
                 .syntax()
@@ -84,14 +75,24 @@ pub(crate) fn add_custom_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<
                 .filter(|t| t.kind() == WHITESPACE)
                 .map(|t| t.text_range())
                 .unwrap_or_else(|| TextRange::new(TextSize::from(0), TextSize::from(0)));
-            edit.delete(line_break_range);
-
-            attr_range.len() + line_break_range.len()
-        };
-
-        edit.set_cursor(start_offset + TextSize::of(&buf) - cursor_delta);
-        buf.push_str("\n}");
-        edit.insert(start_offset, buf);
+            builder.delete(line_break_range);
+        }
+
+        match ctx.config.snippet_cap {
+            Some(cap) => {
+                builder.insert_snippet(
+                    cap,
+                    start_offset,
+                    format!("\n\nimpl {} for {} {{\n    $0\n}}", trait_token, annotated_name),
+                );
+            }
+            None => {
+                builder.insert(
+                    start_offset,
+                    format!("\n\nimpl {} for {} {{\n\n}}", trait_token, annotated_name),
+                );
+            }
+        }
     })
 }
 
@@ -117,7 +118,7 @@ struct Foo {
 }
 
 impl Debug for Foo {
-<|>
+    $0
 }
             ",
         )
@@ -139,7 +140,7 @@ pub struct Foo {
 }
 
 impl Debug for Foo {
-<|>
+    $0
 }
             ",
         )
@@ -158,7 +159,7 @@ struct Foo {}
 struct Foo {}
 
 impl Debug for Foo {
-<|>
+    $0
 }
             ",
         )
diff --git a/crates/ra_assists/src/handlers/add_derive.rs b/crates/ra_assists/src/handlers/add_derive.rs
index fb08c19e9..b123b8498 100644
--- a/crates/ra_assists/src/handlers/add_derive.rs
+++ b/crates/ra_assists/src/handlers/add_derive.rs
@@ -18,31 +18,37 @@ use crate::{AssistContext, AssistId, Assists};
 // ```
 // ->
 // ```
-// #[derive()]
+// #[derive($0)]
 // struct Point {
 //     x: u32,
 //     y: u32,
 // }
 // ```
 pub(crate) fn add_derive(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let cap = ctx.config.snippet_cap?;
     let nominal = ctx.find_node_at_offset::<ast::NominalDef>()?;
     let node_start = derive_insertion_offset(&nominal)?;
     let target = nominal.syntax().text_range();
-    acc.add(AssistId("add_derive"), "Add `#[derive]`", target, |edit| {
+    acc.add(AssistId("add_derive"), "Add `#[derive]`", target, |builder| {
         let derive_attr = nominal
             .attrs()
             .filter_map(|x| x.as_simple_call())
             .filter(|(name, _arg)| name == "derive")
             .map(|(_name, arg)| arg)
             .next();
-        let offset = match derive_attr {
+        match derive_attr {
             None => {
-                edit.insert(node_start, "#[derive()]\n");
-                node_start + TextSize::of("#[derive(")
+                builder.insert_snippet(cap, node_start, "#[derive($0)]\n");
+            }
+            Some(tt) => {
+                // Just move the cursor.
+                builder.insert_snippet(
+                    cap,
+                    tt.syntax().text_range().end() - TextSize::of(')'),
+                    "$0",
+                )
             }
-            Some(tt) => tt.syntax().text_range().end() - TextSize::of(')'),
         };
-        edit.set_cursor(offset)
     })
 }
 
@@ -66,12 +72,12 @@ mod tests {
         check_assist(
             add_derive,
             "struct Foo { a: i32, <|>}",
-            "#[derive(<|>)]\nstruct Foo { a: i32, }",
+            "#[derive($0)]\nstruct Foo { a: i32, }",
         );
         check_assist(
             add_derive,
             "struct Foo { <|> a: i32, }",
-            "#[derive(<|>)]\nstruct Foo {  a: i32, }",
+            "#[derive($0)]\nstruct Foo {  a: i32, }",
         );
     }
 
@@ -80,7 +86,7 @@ mod tests {
         check_assist(
             add_derive,
             "#[derive(Clone)]\nstruct Foo { a: i32<|>, }",
-            "#[derive(Clone<|>)]\nstruct Foo { a: i32, }",
+            "#[derive(Clone$0)]\nstruct Foo { a: i32, }",
         );
     }
 
@@ -96,7 +102,7 @@ struct Foo { a: i32<|>, }
             "
 /// `Foo` is a pretty important struct.
 /// It does stuff.
-#[derive(<|>)]
+#[derive($0)]
 struct Foo { a: i32, }
             ",
         );
diff --git a/crates/ra_assists/src/handlers/add_explicit_type.rs b/crates/ra_assists/src/handlers/add_explicit_type.rs
index 0c7d5e355..770049212 100644
--- a/crates/ra_assists/src/handlers/add_explicit_type.rs
+++ b/crates/ra_assists/src/handlers/add_explicit_type.rs
@@ -25,9 +25,8 @@ pub(crate) fn add_explicit_type(acc: &mut Assists, ctx: &AssistContext) -> Optio
     let stmt = ctx.find_node_at_offset::<LetStmt>()?;
     let module = ctx.sema.scope(stmt.syntax()).module()?;
     let expr = stmt.initializer()?;
-    let pat = stmt.pat()?;
     // Must be a binding
-    let pat = match pat {
+    let pat = match stmt.pat()? {
         ast::Pat::BindPat(bind_pat) => bind_pat,
         _ => return None,
     };
@@ -46,7 +45,7 @@ pub(crate) fn add_explicit_type(acc: &mut Assists, ctx: &AssistContext) -> Optio
     // Assist not applicable if the type has already been specified
     // and it has no placeholders
     let ascribed_ty = stmt.ascribed_type();
-    if let Some(ref ty) = ascribed_ty {
+    if let Some(ty) = &ascribed_ty {
         if ty.syntax().descendants().find_map(ast::PlaceholderType::cast).is_none() {
             return None;
         }
diff --git a/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs b/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
index 6a49b7dbd..eb57b7231 100644
--- a/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
+++ b/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
@@ -1,6 +1,5 @@
 use ra_ide_db::RootDatabase;
 use ra_syntax::ast::{self, AstNode, NameOwner};
-use stdx::format_to;
 use test_utils::tested_by;
 
 use crate::{utils::FamousDefs, AssistContext, AssistId, Assists};
@@ -35,7 +34,7 @@ pub(crate) fn add_from_impl_for_enum(acc: &mut Assists, ctx: &AssistContext) ->
     }
     let field_type = field_list.fields().next()?.type_ref()?;
     let path = match field_type {
-        ast::TypeRef::PathType(p) => p,
+        ast::TypeRef::PathType(it) => it,
         _ => return None,
     };
 
@@ -51,9 +50,7 @@ pub(crate) fn add_from_impl_for_enum(acc: &mut Assists, ctx: &AssistContext) ->
         target,
         |edit| {
             let start_offset = variant.parent_enum().syntax().text_range().end();
-            let mut buf = String::new();
-            format_to!(
-                buf,
+            let buf = format!(
                 r#"
 
 impl From<{0}> for {1} {{
diff --git a/crates/ra_assists/src/handlers/add_function.rs b/crates/ra_assists/src/handlers/add_function.rs
index de016ae4e..24f931a85 100644
--- a/crates/ra_assists/src/handlers/add_function.rs
+++ b/crates/ra_assists/src/handlers/add_function.rs
@@ -4,13 +4,17 @@ use ra_syntax::{
     ast::{
         self,
         edit::{AstNodeEdit, IndentLevel},
-        ArgListOwner, AstNode, ModuleItemOwner,
+        make, ArgListOwner, AstNode, ModuleItemOwner,
     },
     SyntaxKind, SyntaxNode, TextSize,
 };
 use rustc_hash::{FxHashMap, FxHashSet};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{
+    assist_config::SnippetCap,
+    utils::{render_snippet, Cursor},
+    AssistContext, AssistId, Assists,
+};
 
 // Assist: add_function
 //
@@ -33,7 +37,7 @@ use crate::{AssistContext, AssistId, Assists};
 // }
 //
 // fn bar(arg: &str, baz: Baz) {
-//     todo!()
+//     ${0:todo!()}
 // }
 //
 // ```
@@ -58,21 +62,40 @@ pub(crate) fn add_function(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     let function_builder = FunctionBuilder::from_call(&ctx, &call, &path, target_module)?;
 
     let target = call.syntax().text_range();
-    acc.add(AssistId("add_function"), "Add function", target, |edit| {
+    acc.add(AssistId("add_function"), "Add function", target, |builder| {
         let function_template = function_builder.render();
-        edit.set_file(function_template.file);
-        edit.set_cursor(function_template.cursor_offset);
-        edit.insert(function_template.insert_offset, function_template.fn_def.to_string());
+        builder.set_file(function_template.file);
+        let new_fn = function_template.to_string(ctx.config.snippet_cap);
+        match ctx.config.snippet_cap {
+            Some(cap) => builder.insert_snippet(cap, function_template.insert_offset, new_fn),
+            None => builder.insert(function_template.insert_offset, new_fn),
+        }
     })
 }
 
 struct FunctionTemplate {
     insert_offset: TextSize,
-    cursor_offset: TextSize,
-    fn_def: ast::SourceFile,
+    placeholder_expr: ast::MacroCall,
+    leading_ws: String,
+    fn_def: ast::FnDef,
+    trailing_ws: String,
     file: FileId,
 }
 
+impl FunctionTemplate {
+    fn to_string(&self, cap: Option<SnippetCap>) -> String {
+        let f = match cap {
+            Some(cap) => render_snippet(
+                cap,
+                self.fn_def.syntax(),
+                Cursor::Replace(self.placeholder_expr.syntax()),
+            ),
+            None => self.fn_def.to_string(),
+        };
+        format!("{}{}{}", self.leading_ws, f, self.trailing_ws)
+    }
+}
+
 struct FunctionBuilder {
     target: GeneratedFunctionTarget,
     fn_name: ast::Name,
@@ -110,35 +133,41 @@ impl FunctionBuilder {
     }
 
     fn render(self) -> FunctionTemplate {
-        let placeholder_expr = ast::make::expr_todo();
-        let fn_body = ast::make::block_expr(vec![], Some(placeholder_expr));
-        let mut fn_def = ast::make::fn_def(self.fn_name, self.type_params, self.params, fn_body);
-        if self.needs_pub {
-            fn_def = ast::make::add_pub_crate_modifier(fn_def);
-        }
-
-        let (fn_def, insert_offset) = match self.target {
+        let placeholder_expr = make::expr_todo();
+        let fn_body = make::block_expr(vec![], Some(placeholder_expr));
+        let visibility = if self.needs_pub { Some(make::visibility_pub_crate()) } else { None };
+        let mut fn_def =
+            make::fn_def(visibility, self.fn_name, self.type_params, self.params, fn_body);
+        let leading_ws;
+        let trailing_ws;
+
+        let insert_offset = match self.target {
             GeneratedFunctionTarget::BehindItem(it) => {
-                let with_leading_blank_line = ast::make::add_leading_newlines(2, fn_def);
-                let indented = with_leading_blank_line.indent(IndentLevel::from_node(&it));
-                (indented, it.text_range().end())
+                let indent = IndentLevel::from_node(&it);
+                leading_ws = format!("\n\n{}", indent);
+                fn_def = fn_def.indent(indent);
+                trailing_ws = String::new();
+                it.text_range().end()
             }
             GeneratedFunctionTarget::InEmptyItemList(it) => {
-                let indent_once = IndentLevel(1);
                 let indent = IndentLevel::from_node(it.syntax());
-                let fn_def = ast::make::add_leading_newlines(1, fn_def);
-                let fn_def = fn_def.indent(indent_once);
-                let fn_def = ast::make::add_trailing_newlines(1, fn_def);
-                let fn_def = fn_def.indent(indent);
-                (fn_def, it.syntax().text_range().start() + TextSize::of('{'))
+                leading_ws = format!("\n{}", indent + 1);
+                fn_def = fn_def.indent(indent + 1);
+                trailing_ws = format!("\n{}", indent);
+                it.syntax().text_range().start() + TextSize::of('{')
             }
         };
 
         let placeholder_expr =
             fn_def.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
-        let cursor_offset_from_fn_start = placeholder_expr.syntax().text_range().start();
-        let cursor_offset = insert_offset + cursor_offset_from_fn_start;
-        FunctionTemplate { insert_offset, cursor_offset, fn_def, file: self.file }
+        FunctionTemplate {
+            insert_offset,
+            placeholder_expr,
+            leading_ws,
+            fn_def,
+            trailing_ws,
+            file: self.file,
+        }
     }
 }
 
@@ -158,7 +187,7 @@ impl GeneratedFunctionTarget {
 
 fn fn_name(call: &ast::Path) -> Option<ast::Name> {
     let name = call.segment()?.syntax().to_string();
-    Some(ast::make::name(&name))
+    Some(make::name(&name))
 }
 
 /// Computes the type variables and arguments required for the generated function
@@ -180,8 +209,8 @@ fn fn_args(
         });
     }
     deduplicate_arg_names(&mut arg_names);
-    let params = arg_names.into_iter().zip(arg_types).map(|(name, ty)| ast::make::param(name, ty));
-    Some((None, ast::make::param_list(params)))
+    let params = arg_names.into_iter().zip(arg_types).map(|(name, ty)| make::param(name, ty));
+    Some((None, make::param_list(params)))
 }
 
 /// Makes duplicate argument names unique by appending incrementing numbers.
@@ -316,7 +345,7 @@ fn foo() {
 }
 
 fn bar() {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -343,7 +372,7 @@ impl Foo {
 }
 
 fn bar() {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -367,7 +396,7 @@ fn foo1() {
 }
 
 fn bar() {
-    <|>todo!()
+    ${0:todo!()}
 }
 
 fn foo2() {}
@@ -393,7 +422,7 @@ mod baz {
     }
 
     fn bar() {
-        <|>todo!()
+        ${0:todo!()}
     }
 }
 ",
@@ -419,7 +448,7 @@ fn foo() {
 }
 
 fn bar(baz: Baz) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         );
@@ -452,7 +481,7 @@ impl Baz {
 }
 
 fn bar(baz: Baz) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -473,7 +502,7 @@ fn foo() {
 }
 
 fn bar(arg: &str) {
-    <|>todo!()
+    ${0:todo!()}
 }
 "#,
         )
@@ -494,7 +523,7 @@ fn foo() {
 }
 
 fn bar(arg: char) {
-    <|>todo!()
+    ${0:todo!()}
 }
 "#,
         )
@@ -515,7 +544,7 @@ fn foo() {
 }
 
 fn bar(arg: i32) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -536,7 +565,7 @@ fn foo() {
 }
 
 fn bar(arg: u8) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -561,7 +590,7 @@ fn foo() {
 }
 
 fn bar(x: u8) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -584,7 +613,7 @@ fn foo() {
 }
 
 fn bar(worble: ()) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -613,7 +642,7 @@ fn baz() {
 }
 
 fn bar(foo: impl Foo) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -640,7 +669,7 @@ fn foo() {
 }
 
 fn bar(baz: &Baz) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -669,7 +698,7 @@ fn foo() {
 }
 
 fn bar(baz: Baz::Bof) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -692,7 +721,7 @@ fn foo<T>(t: T) {
 }
 
 fn bar<T>(t: T) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -723,7 +752,7 @@ fn foo() {
 }
 
 fn bar(arg: fn() -> Baz) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -748,7 +777,7 @@ fn foo() {
 }
 
 fn bar(closure: impl Fn(i64) -> i64) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -769,7 +798,7 @@ fn foo() {
 }
 
 fn bar(baz: ()) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -794,7 +823,7 @@ fn foo() {
 }
 
 fn bar(baz_1: Baz, baz_2: Baz) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -819,7 +848,7 @@ fn foo() {
 }
 
 fn bar(baz_1: Baz, baz_2: Baz, arg_1: &str, arg_2: &str) {
-    <|>todo!()
+    ${0:todo!()}
 }
 "#,
         )
@@ -839,7 +868,7 @@ fn foo() {
             r"
 mod bar {
     pub(crate) fn my_fn() {
-        <|>todo!()
+        ${0:todo!()}
     }
 }
 
@@ -878,7 +907,7 @@ fn bar() {
 }
 
 fn baz(foo: foo::Foo) {
-    <|>todo!()
+    ${0:todo!()}
 }
 ",
         )
@@ -902,7 +931,7 @@ mod bar {
     fn something_else() {}
 
     pub(crate) fn my_fn() {
-        <|>todo!()
+        ${0:todo!()}
     }
 }
 
@@ -930,7 +959,7 @@ fn foo() {
 mod bar {
     mod baz {
         pub(crate) fn my_fn() {
-            <|>todo!()
+            ${0:todo!()}
         }
     }
 }
@@ -959,7 +988,7 @@ fn main() {
 
 
 pub(crate) fn bar() {
-    <|>todo!()
+    ${0:todo!()}
 }",
         )
     }
diff --git a/crates/ra_assists/src/handlers/add_impl.rs b/crates/ra_assists/src/handlers/add_impl.rs
index df114a0d8..eceba7d0a 100644
--- a/crates/ra_assists/src/handlers/add_impl.rs
+++ b/crates/ra_assists/src/handlers/add_impl.rs
@@ -1,7 +1,4 @@
-use ra_syntax::{
-    ast::{self, AstNode, NameOwner, TypeParamsOwner},
-    TextSize,
-};
+use ra_syntax::ast::{self, AstNode, NameOwner, TypeParamsOwner};
 use stdx::{format_to, SepBy};
 
 use crate::{AssistContext, AssistId, Assists};
@@ -12,17 +9,17 @@ use crate::{AssistContext, AssistId, Assists};
 //
 // ```
 // struct Ctx<T: Clone> {
-//      data: T,<|>
+//     data: T,<|>
 // }
 // ```
 // ->
 // ```
 // struct Ctx<T: Clone> {
-//      data: T,
+//     data: T,
 // }
 //
 // impl<T: Clone> Ctx<T> {
-//
+//     $0
 // }
 // ```
 pub(crate) fn add_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
@@ -50,30 +47,37 @@ pub(crate) fn add_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
             let generic_params = lifetime_params.chain(type_params).sep_by(", ");
             format_to!(buf, "<{}>", generic_params)
         }
-        buf.push_str(" {\n");
-        edit.set_cursor(start_offset + TextSize::of(&buf));
-        buf.push_str("\n}");
-        edit.insert(start_offset, buf);
+        match ctx.config.snippet_cap {
+            Some(cap) => {
+                buf.push_str(" {\n    $0\n}");
+                edit.insert_snippet(cap, start_offset, buf);
+            }
+            None => {
+                buf.push_str(" {\n}");
+                edit.insert(start_offset, buf);
+            }
+        }
     })
 }
 
 #[cfg(test)]
 mod tests {
-    use super::*;
     use crate::tests::{check_assist, check_assist_target};
 
+    use super::*;
+
     #[test]
     fn test_add_impl() {
-        check_assist(add_impl, "struct Foo {<|>}\n", "struct Foo {}\n\nimpl Foo {\n<|>\n}\n");
+        check_assist(add_impl, "struct Foo {<|>}\n", "struct Foo {}\n\nimpl Foo {\n    $0\n}\n");
         check_assist(
             add_impl,
             "struct Foo<T: Clone> {<|>}",
-            "struct Foo<T: Clone> {}\n\nimpl<T: Clone> Foo<T> {\n<|>\n}",
+            "struct Foo<T: Clone> {}\n\nimpl<T: Clone> Foo<T> {\n    $0\n}",
         );
         check_assist(
             add_impl,
             "struct Foo<'a, T: Foo<'a>> {<|>}",
-            "struct Foo<'a, T: Foo<'a>> {}\n\nimpl<'a, T: Foo<'a>> Foo<'a, T> {\n<|>\n}",
+            "struct Foo<'a, T: Foo<'a>> {}\n\nimpl<'a, T: Foo<'a>> Foo<'a, T> {\n    $0\n}",
         );
     }
 
diff --git a/crates/ra_assists/src/handlers/add_missing_impl_members.rs b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
index 22e1156d2..abacd4065 100644
--- a/crates/ra_assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
@@ -11,7 +11,7 @@ use ra_syntax::{
 use crate::{
     assist_context::{AssistContext, Assists},
     ast_transform::{self, AstTransform, QualifyPaths, SubstituteTypeParams},
-    utils::{get_missing_assoc_items, resolve_target_trait},
+    utils::{get_missing_assoc_items, render_snippet, resolve_target_trait, Cursor},
     AssistId,
 };
 
@@ -46,7 +46,7 @@ enum AddMissingImplMembersMode {
 //
 // impl Trait<u32> for () {
 //     fn foo(&self) -> u32 {
-//         todo!()
+//         ${0:todo!()}
 //     }
 //
 // }
@@ -89,7 +89,7 @@ pub(crate) fn add_missing_impl_members(acc: &mut Assists, ctx: &AssistContext) -
 // impl Trait for () {
 //     Type X = ();
 //     fn foo(&self) {}
-//     fn bar(&self) {}
+//     $0fn bar(&self) {}
 //
 // }
 // ```
@@ -147,7 +147,7 @@ fn add_missing_impl_members_inner(
     }
 
     let target = impl_def.syntax().text_range();
-    acc.add(AssistId(assist_id), label, target, |edit| {
+    acc.add(AssistId(assist_id), label, target, |builder| {
         let n_existing_items = impl_item_list.assoc_items().count();
         let source_scope = ctx.sema.scope_for_def(trait_);
         let target_scope = ctx.sema.scope(impl_item_list.syntax());
@@ -162,13 +162,29 @@ fn add_missing_impl_members_inner(
             })
             .map(|it| edit::remove_attrs_and_docs(&it));
         let new_impl_item_list = impl_item_list.append_items(items);
-        let cursor_position = {
-            let first_new_item = new_impl_item_list.assoc_items().nth(n_existing_items).unwrap();
-            first_new_item.syntax().text_range().start()
+        let first_new_item = new_impl_item_list.assoc_items().nth(n_existing_items).unwrap();
+
+        let original_range = impl_item_list.syntax().text_range();
+        match ctx.config.snippet_cap {
+            None => builder.replace(original_range, new_impl_item_list.to_string()),
+            Some(cap) => {
+                let mut cursor = Cursor::Before(first_new_item.syntax());
+                let placeholder;
+                if let ast::AssocItem::FnDef(func) = &first_new_item {
+                    if let Some(m) = func.syntax().descendants().find_map(ast::MacroCall::cast) {
+                        if m.syntax().text() == "todo!()" {
+                            placeholder = m;
+                            cursor = Cursor::Replace(placeholder.syntax());
+                        }
+                    }
+                }
+                builder.replace_snippet(
+                    cap,
+                    original_range,
+                    render_snippet(cap, new_impl_item_list.syntax(), cursor),
+                )
+            }
         };
-
-        edit.replace_ast(impl_item_list, new_impl_item_list);
-        edit.set_cursor(cursor_position);
     })
 }
 
@@ -222,7 +238,7 @@ struct S;
 
 impl Foo for S {
     fn bar(&self) {}
-    <|>type Output;
+    $0type Output;
     const CONST: usize = 42;
     fn foo(&self) {
         todo!()
@@ -263,8 +279,8 @@ struct S;
 
 impl Foo for S {
     fn bar(&self) {}
-    <|>fn foo(&self) {
-        todo!()
+    fn foo(&self) {
+        ${0:todo!()}
     }
 
 }"#,
@@ -283,8 +299,8 @@ impl Foo for S { <|> }"#,
 trait Foo { fn foo(&self); }
 struct S;
 impl Foo for S {
-    <|>fn foo(&self) {
-        todo!()
+    fn foo(&self) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -302,8 +318,8 @@ impl Foo<u32> for S { <|> }"#,
 trait Foo<T> { fn foo(&self, t: T) -> &T; }
 struct S;
 impl Foo<u32> for S {
-    <|>fn foo(&self, t: u32) -> &u32 {
-        todo!()
+    fn foo(&self, t: u32) -> &u32 {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -321,8 +337,8 @@ impl<U> Foo<U> for S { <|> }"#,
 trait Foo<T> { fn foo(&self, t: T) -> &T; }
 struct S;
 impl<U> Foo<U> for S {
-    <|>fn foo(&self, t: U) -> &U {
-        todo!()
+    fn foo(&self, t: U) -> &U {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -340,8 +356,8 @@ impl Foo for S {}<|>"#,
 trait Foo { fn foo(&self); }
 struct S;
 impl Foo for S {
-    <|>fn foo(&self) {
-        todo!()
+    fn foo(&self) {
+        ${0:todo!()}
     }
 }"#,
         )
@@ -365,8 +381,8 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar) {
-        todo!()
+    fn foo(&self, bar: foo::Bar) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -390,8 +406,8 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>) {
-        todo!()
+    fn foo(&self, bar: foo::Bar<u32>) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -415,8 +431,8 @@ mod foo {
 }
 struct S;
 impl foo::Foo<u32> for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>) {
-        todo!()
+    fn foo(&self, bar: foo::Bar<u32>) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -443,8 +459,8 @@ mod foo {
 struct Param;
 struct S;
 impl foo::Foo<Param> for S {
-    <|>fn foo(&self, bar: Param) {
-        todo!()
+    fn foo(&self, bar: Param) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -470,8 +486,8 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>::Assoc) {
-        todo!()
+    fn foo(&self, bar: foo::Bar<u32>::Assoc) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -497,8 +513,8 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<foo::Baz>) {
-        todo!()
+    fn foo(&self, bar: foo::Bar<foo::Baz>) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -522,8 +538,8 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: dyn Fn(u32) -> i32) {
-        todo!()
+    fn foo(&self, bar: dyn Fn(u32) -> i32) {
+        ${0:todo!()}
     }
 }"#,
         );
@@ -580,7 +596,7 @@ trait Foo {
 }
 struct S;
 impl Foo for S {
-    <|>type Output;
+    $0type Output;
     fn foo(&self) {
         todo!()
     }
@@ -614,7 +630,7 @@ trait Foo {
 }
 struct S;
 impl Foo for S {
-    <|>fn valid(some: u32) -> bool { false }
+    $0fn valid(some: u32) -> bool { false }
 }"#,
         )
     }
@@ -637,8 +653,8 @@ trait Foo<T = Self> {
 
 struct S;
 impl Foo for S {
-    <|>fn bar(&self, other: &Self) {
-        todo!()
+    fn bar(&self, other: &Self) {
+        ${0:todo!()}
     }
 }"#,
         )
@@ -662,8 +678,8 @@ trait Foo<T1, T2 = Self> {
 
 struct S<T>;
 impl Foo<T> for S<T> {
-    <|>fn bar(&self, this: &T, that: &Self) {
-        todo!()
+    fn bar(&self, this: &T, that: &Self) {
+        ${0:todo!()}
     }
 }"#,
         )
diff --git a/crates/ra_assists/src/handlers/add_turbo_fish.rs b/crates/ra_assists/src/handlers/add_turbo_fish.rs
new file mode 100644
index 000000000..a0363bc78
--- /dev/null
+++ b/crates/ra_assists/src/handlers/add_turbo_fish.rs
@@ -0,0 +1,134 @@
+use ra_ide_db::defs::{classify_name_ref, Definition, NameRefClass};
+use ra_syntax::{ast, AstNode, SyntaxKind, T};
+
+use crate::{
+    assist_context::{AssistContext, Assists},
+    AssistId,
+};
+use test_utils::tested_by;
+
+// Assist: add_turbo_fish
+//
+// Adds `::<_>` to a call of a generic method or function.
+//
+// ```
+// fn make<T>() -> T { todo!() }
+// fn main() {
+//     let x = make<|>();
+// }
+// ```
+// ->
+// ```
+// fn make<T>() -> T { todo!() }
+// fn main() {
+//     let x = make::<${0:_}>();
+// }
+// ```
+pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let ident = ctx.find_token_at_offset(SyntaxKind::IDENT)?;
+    let next_token = ident.next_token()?;
+    if next_token.kind() == T![::] {
+        tested_by!(add_turbo_fish_one_fish_is_enough);
+        return None;
+    }
+    let name_ref = ast::NameRef::cast(ident.parent())?;
+    let def = match classify_name_ref(&ctx.sema, &name_ref)? {
+        NameRefClass::Definition(def) => def,
+        NameRefClass::FieldShorthand { .. } => return None,
+    };
+    let fun = match def {
+        Definition::ModuleDef(hir::ModuleDef::Function(it)) => it,
+        _ => return None,
+    };
+    let generics = hir::GenericDef::Function(fun).params(ctx.sema.db);
+    if generics.is_empty() {
+        tested_by!(add_turbo_fish_non_generic);
+        return None;
+    }
+    acc.add(AssistId("add_turbo_fish"), "Add `::<>`", ident.text_range(), |builder| {
+        match ctx.config.snippet_cap {
+            Some(cap) => builder.insert_snippet(cap, ident.text_range().end(), "::<${0:_}>"),
+            None => builder.insert(ident.text_range().end(), "::<_>"),
+        }
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{check_assist, check_assist_not_applicable};
+
+    use super::*;
+    use test_utils::covers;
+
+    #[test]
+    fn add_turbo_fish_function() {
+        check_assist(
+            add_turbo_fish,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    make<|>();
+}
+"#,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    make::<${0:_}>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn add_turbo_fish_method() {
+        check_assist(
+            add_turbo_fish,
+            r#"
+struct S;
+impl S {
+    fn make<T>(&self) -> T {}
+}
+fn main() {
+    S.make<|>();
+}
+"#,
+            r#"
+struct S;
+impl S {
+    fn make<T>(&self) -> T {}
+}
+fn main() {
+    S.make::<${0:_}>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn add_turbo_fish_one_fish_is_enough() {
+        covers!(add_turbo_fish_one_fish_is_enough);
+        check_assist_not_applicable(
+            add_turbo_fish,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    make<|>::<()>();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn add_turbo_fish_non_generic() {
+        covers!(add_turbo_fish_non_generic);
+        check_assist_not_applicable(
+            add_turbo_fish,
+            r#"
+fn make() -> () {}
+fn main() {
+    make<|>();
+}
+"#,
+        );
+    }
+}
diff --git a/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs b/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
index c4b56f6e9..b379b55a8 100644
--- a/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
+++ b/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
@@ -51,7 +51,7 @@ pub(crate) fn replace_unwrap_with_match(acc: &mut Assists, ctx: &AssistContext)
         let bind_path = make::path_unqualified(make::path_segment(make::name_ref("a")));
         let ok_arm = make::match_arm(iter::once(ok_tuple), make::expr_path(bind_path));
 
-        let unreachable_call = make::unreachable_macro_call().into();
+        let unreachable_call = make::expr_unreachable();
         let err_arm = make::match_arm(iter::once(make::placeholder_pat().into()), unreachable_call);
 
         let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index b6dc7cb1b..339f24100 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -10,6 +10,7 @@ macro_rules! eprintln {
     ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
 }
 
+mod assist_config;
 mod assist_context;
 mod marks;
 #[cfg(test)]
@@ -24,6 +25,8 @@ use ra_syntax::TextRange;
 
 pub(crate) use crate::assist_context::{AssistContext, Assists};
 
+pub use assist_config::AssistConfig;
+
 /// Unique identifier of the assist, should not be shown to the user
 /// directly.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -54,9 +57,9 @@ impl Assist {
     ///
     /// Assists are returned in the "unresolved" state, that is only labels are
     /// returned, without actual edits.
-    pub fn unresolved(db: &RootDatabase, range: FileRange) -> Vec<Assist> {
+    pub fn unresolved(db: &RootDatabase, config: &AssistConfig, range: FileRange) -> Vec<Assist> {
         let sema = Semantics::new(db);
-        let ctx = AssistContext::new(sema, range);
+        let ctx = AssistContext::new(sema, config, range);
         let mut acc = Assists::new_unresolved(&ctx);
         handlers::all().iter().for_each(|handler| {
             handler(&mut acc, &ctx);
@@ -68,9 +71,13 @@ impl Assist {
     ///
     /// Assists are returned in the "resolved" state, that is with edit fully
     /// computed.
-    pub fn resolved(db: &RootDatabase, range: FileRange) -> Vec<ResolvedAssist> {
+    pub fn resolved(
+        db: &RootDatabase,
+        config: &AssistConfig,
+        range: FileRange,
+    ) -> Vec<ResolvedAssist> {
         let sema = Semantics::new(db);
-        let ctx = AssistContext::new(sema, range);
+        let ctx = AssistContext::new(sema, config, range);
         let mut acc = Assists::new_resolved(&ctx);
         handlers::all().iter().for_each(|handler| {
             handler(&mut acc, &ctx);
@@ -103,6 +110,7 @@ mod handlers {
     mod add_impl;
     mod add_missing_impl_members;
     mod add_new;
+    mod add_turbo_fish;
     mod apply_demorgan;
     mod auto_import;
     mod change_return_type_to_result;
@@ -140,6 +148,7 @@ mod handlers {
             add_function::add_function,
             add_impl::add_impl,
             add_new::add_new,
+            add_turbo_fish::add_turbo_fish,
             apply_demorgan::apply_demorgan,
             auto_import::auto_import,
             change_return_type_to_result::change_return_type_to_result,
diff --git a/crates/ra_assists/src/marks.rs b/crates/ra_assists/src/marks.rs
index 8d910205f..d579e627f 100644
--- a/crates/ra_assists/src/marks.rs
+++ b/crates/ra_assists/src/marks.rs
@@ -9,4 +9,6 @@ test_utils::marks![
     test_not_applicable_if_variable_unused
     change_visibility_field_false_positive
     test_add_from_impl_already_exists
+    add_turbo_fish_one_fish_is_enough
+    add_turbo_fish_non_generic
 ];
diff --git a/crates/ra_assists/src/tests.rs b/crates/ra_assists/src/tests.rs
index a3eacb8f1..9ba3da786 100644
--- a/crates/ra_assists/src/tests.rs
+++ b/crates/ra_assists/src/tests.rs
@@ -11,7 +11,7 @@ use test_utils::{
     RangeOrOffset,
 };
 
-use crate::{handlers::Handler, Assist, AssistContext, Assists};
+use crate::{handlers::Handler, Assist, AssistConfig, AssistContext, Assists};
 
 pub(crate) fn with_single_file(text: &str) -> (RootDatabase, FileId) {
     let (mut db, file_id) = RootDatabase::with_single_file(text);
@@ -41,14 +41,14 @@ fn check_doc_test(assist_id: &str, before: &str, after: &str) {
     let (db, file_id) = crate::tests::with_single_file(&before);
     let frange = FileRange { file_id, range: selection.into() };
 
-    let mut assist = Assist::resolved(&db, frange)
+    let mut assist = Assist::resolved(&db, &AssistConfig::default(), frange)
         .into_iter()
         .find(|assist| assist.assist.id.0 == assist_id)
         .unwrap_or_else(|| {
             panic!(
                 "\n\nAssist is not applicable: {}\nAvailable assists: {}",
                 assist_id,
-                Assist::resolved(&db, frange)
+                Assist::resolved(&db, &AssistConfig::default(), frange)
                     .into_iter()
                     .map(|assist| assist.assist.id.0)
                     .collect::<Vec<_>>()
@@ -90,7 +90,8 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult) {
     let frange = FileRange { file_id: file_with_caret_id, range: range_or_offset.into() };
 
     let sema = Semantics::new(&db);
-    let ctx = AssistContext::new(sema, frange);
+    let config = AssistConfig::default();
+    let ctx = AssistContext::new(sema, &config, frange);
     let mut acc = Assists::new_resolved(&ctx);
     handler(&mut acc, &ctx);
     let mut res = acc.finish_resolved();
@@ -103,19 +104,20 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult) {
             let mut actual = db.file_text(change.file_id).as_ref().to_owned();
             change.edit.apply(&mut actual);
 
-            match source_change.cursor_position {
-                None => {
-                    if let RangeOrOffset::Offset(before_cursor_pos) = range_or_offset {
-                        let off = change
-                            .edit
-                            .apply_to_offset(before_cursor_pos)
-                            .expect("cursor position is affected by the edit");
-                        actual = add_cursor(&actual, off)
+            if !source_change.is_snippet {
+                match source_change.cursor_position {
+                    None => {
+                        if let RangeOrOffset::Offset(before_cursor_pos) = range_or_offset {
+                            let off = change
+                                .edit
+                                .apply_to_offset(before_cursor_pos)
+                                .expect("cursor position is affected by the edit");
+                            actual = add_cursor(&actual, off)
+                        }
                     }
-                }
-                Some(off) => actual = add_cursor(&actual, off.offset),
-            };
-
+                    Some(off) => actual = add_cursor(&actual, off.offset),
+                };
+            }
             assert_eq_text!(after, &actual);
         }
         (Some(assist), ExpectedResult::Target(target)) => {
@@ -136,7 +138,7 @@ fn assist_order_field_struct() {
     let (before_cursor_pos, before) = extract_offset(before);
     let (db, file_id) = with_single_file(&before);
     let frange = FileRange { file_id, range: TextRange::empty(before_cursor_pos) };
-    let assists = Assist::resolved(&db, frange);
+    let assists = Assist::resolved(&db, &AssistConfig::default(), frange);
     let mut assists = assists.iter();
 
     assert_eq!(
@@ -159,7 +161,7 @@ fn assist_order_if_expr() {
     let (range, before) = extract_range(before);
     let (db, file_id) = with_single_file(&before);
     let frange = FileRange { file_id, range };
-    let assists = Assist::resolved(&db, frange);
+    let assists = Assist::resolved(&db, &AssistConfig::default(), frange);
     let mut assists = assists.iter();
 
     assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
diff --git a/crates/ra_assists/src/tests/generated.rs b/crates/ra_assists/src/tests/generated.rs
index 972dbd251..3808aded1 100644
--- a/crates/ra_assists/src/tests/generated.rs
+++ b/crates/ra_assists/src/tests/generated.rs
@@ -15,7 +15,7 @@ struct S;
 struct S;
 
 impl Debug for S {
-
+    $0
 }
 "#####,
     )
@@ -32,7 +32,7 @@ struct Point {
 }
 "#####,
         r#####"
-#[derive()]
+#[derive($0)]
 struct Point {
     x: u32,
     y: u32,
@@ -78,7 +78,7 @@ fn foo() {
 }
 
 fn bar(arg: &str, baz: Baz) {
-    todo!()
+    ${0:todo!()}
 }
 
 "#####,
@@ -108,16 +108,16 @@ fn doctest_add_impl() {
         "add_impl",
         r#####"
 struct Ctx<T: Clone> {
-     data: T,<|>
+    data: T,<|>
 }
 "#####,
         r#####"
 struct Ctx<T: Clone> {
-     data: T,
+    data: T,
 }
 
 impl<T: Clone> Ctx<T> {
-
+    $0
 }
 "#####,
     )
@@ -150,7 +150,7 @@ trait Trait {
 impl Trait for () {
     Type X = ();
     fn foo(&self) {}
-    fn bar(&self) {}
+    $0fn bar(&self) {}
 
 }
 "#####,
@@ -181,7 +181,7 @@ trait Trait<T> {
 
 impl Trait<u32> for () {
     fn foo(&self) -> u32 {
-        todo!()
+        ${0:todo!()}
     }
 
 }
@@ -212,6 +212,25 @@ impl<T: Clone> Ctx<T> {
 }
 
 #[test]
+fn doctest_add_turbo_fish() {
+    check_doc_test(
+        "add_turbo_fish",
+        r#####"
+fn make<T>() -> T { todo!() }
+fn main() {
+    let x = make<|>();
+}
+"#####,
+        r#####"
+fn make<T>() -> T { todo!() }
+fn main() {
+    let x = make::<${0:_}>();
+}
+"#####,
+    )
+}
+
+#[test]
 fn doctest_apply_demorgan() {
     check_doc_test(
         "apply_demorgan",
diff --git a/crates/ra_assists/src/utils.rs b/crates/ra_assists/src/utils.rs
index f3fc92ebf..9af27180b 100644
--- a/crates/ra_assists/src/utils.rs
+++ b/crates/ra_assists/src/utils.rs
@@ -1,18 +1,57 @@
 //! Assorted functions shared by several assists.
 pub(crate) mod insert_use;
 
-use std::iter;
+use std::{iter, ops};
 
 use hir::{Adt, Crate, Semantics, Trait, Type};
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
     ast::{self, make, NameOwner},
-    AstNode, T,
+    AstNode, SyntaxNode, T,
 };
 use rustc_hash::FxHashSet;
 
+use crate::assist_config::SnippetCap;
+
 pub(crate) use insert_use::insert_use_statement;
 
+#[derive(Clone, Copy, Debug)]
+pub(crate) enum Cursor<'a> {
+    Replace(&'a SyntaxNode),
+    Before(&'a SyntaxNode),
+}
+
+impl<'a> Cursor<'a> {
+    fn node(self) -> &'a SyntaxNode {
+        match self {
+            Cursor::Replace(node) | Cursor::Before(node) => node,
+        }
+    }
+}
+
+pub(crate) fn render_snippet(_cap: SnippetCap, node: &SyntaxNode, cursor: Cursor) -> String {
+    assert!(cursor.node().ancestors().any(|it| it == *node));
+    let range = cursor.node().text_range() - node.text_range().start();
+    let range: ops::Range<usize> = range.into();
+
+    let mut placeholder = cursor.node().to_string();
+    escape(&mut placeholder);
+    let tab_stop = match cursor {
+        Cursor::Replace(placeholder) => format!("${{0:{}}}", placeholder),
+        Cursor::Before(placeholder) => format!("$0{}", placeholder),
+    };
+
+    let mut buf = node.to_string();
+    buf.replace_range(range, &tab_stop);
+    return buf;
+
+    fn escape(buf: &mut String) {
+        stdx::replace(buf, '{', r"\{");
+        stdx::replace(buf, '}', r"\}");
+        stdx::replace(buf, '$', r"\$");
+    }
+}
+
 pub fn get_missing_assoc_items(
     sema: &Semantics<RootDatabase>,
     impl_def: &ast::ImplDef,
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index 498a4c917..2f71511ba 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -112,7 +112,7 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
     #[salsa::invoke(Documentation::documentation_query)]
     fn documentation(&self, def: AttrDefId) -> Option<Documentation>;
 
-    #[salsa::invoke(find_path::importable_locations_in_crate)]
+    #[salsa::invoke(find_path::importable_locations_of_query)]
     fn importable_locations_of(
         &self,
         item: ItemInNs,
diff --git a/crates/ra_hir_def/src/find_path.rs b/crates/ra_hir_def/src/find_path.rs
index 1ca20fabd..2eb12ec8f 100644
--- a/crates/ra_hir_def/src/find_path.rs
+++ b/crates/ra_hir_def/src/find_path.rs
@@ -1,5 +1,11 @@
 //! An algorithm to find a path to refer to a certain item.
 
+use std::sync::Arc;
+
+use hir_expand::name::{known, AsName, Name};
+use ra_prof::profile;
+use test_utils::tested_by;
+
 use crate::{
     db::DefDatabase,
     item_scope::ItemInNs,
@@ -7,26 +13,28 @@ use crate::{
     visibility::Visibility,
     CrateId, ModuleDefId, ModuleId,
 };
-use hir_expand::name::{known, AsName, Name};
-use std::sync::Arc;
-use test_utils::tested_by;
+
+// FIXME: handle local items
+
+/// Find a path that can be used to refer to a certain item. This can depend on
+/// *from where* you're referring to the item, hence the `from` parameter.
+pub fn find_path(db: &dyn DefDatabase, item: ItemInNs, from: ModuleId) -> Option<ModPath> {
+    let _p = profile("find_path");
+    find_path_inner(db, item, from, MAX_PATH_LEN)
+}
 
 const MAX_PATH_LEN: usize = 15;
 
 impl ModPath {
     fn starts_with_std(&self) -> bool {
-        self.segments.first().filter(|&first_segment| first_segment == &known::std).is_some()
+        self.segments.first() == Some(&known::std)
     }
 
     // When std library is present, paths starting with `std::`
     // should be preferred over paths starting with `core::` and `alloc::`
     fn can_start_with_std(&self) -> bool {
-        self.segments
-            .first()
-            .filter(|&first_segment| {
-                first_segment == &known::alloc || first_segment == &known::core
-            })
-            .is_some()
+        let first_segment = self.segments.first();
+        first_segment == Some(&known::alloc) || first_segment == Some(&known::core)
     }
 
     fn len(&self) -> usize {
@@ -41,15 +49,6 @@ impl ModPath {
     }
 }
 
-// FIXME: handle local items
-
-/// Find a path that can be used to refer to a certain item. This can depend on
-/// *from where* you're referring to the item, hence the `from` parameter.
-pub fn find_path(db: &dyn DefDatabase, item: ItemInNs, from: ModuleId) -> Option<ModPath> {
-    let _p = ra_prof::profile("find_path");
-    find_path_inner(db, item, from, MAX_PATH_LEN)
-}
-
 fn find_path_inner(
     db: &dyn DefDatabase,
     item: ItemInNs,
@@ -215,11 +214,12 @@ fn find_importable_locations(
 ///
 /// Note that the crate doesn't need to be the one in which the item is defined;
 /// it might be re-exported in other crates.
-pub(crate) fn importable_locations_in_crate(
+pub(crate) fn importable_locations_of_query(
     db: &dyn DefDatabase,
     item: ItemInNs,
     krate: CrateId,
 ) -> Arc<[(ModuleId, Name, Visibility)]> {
+    let _p = profile("importable_locations_of_query");
     let def_map = db.crate_def_map(krate);
     let mut result = Vec::new();
     for (local_id, data) in def_map.modules.iter() {
diff --git a/crates/ra_ide/src/completion.rs b/crates/ra_ide/src/completion.rs
index 8bdc43b1a..191300704 100644
--- a/crates/ra_ide/src/completion.rs
+++ b/crates/ra_ide/src/completion.rs
@@ -59,8 +59,8 @@ pub use crate::completion::{
 /// with ordering of completions (currently this is done by the client).
 pub(crate) fn completions(
     db: &RootDatabase,
-    position: FilePosition,
     config: &CompletionConfig,
+    position: FilePosition,
 ) -> Option<Completions> {
     let ctx = CompletionContext::new(db, position, config)?;
 
diff --git a/crates/ra_ide/src/completion/test_utils.rs b/crates/ra_ide/src/completion/test_utils.rs
index eb90b5279..bf22452a2 100644
--- a/crates/ra_ide/src/completion/test_utils.rs
+++ b/crates/ra_ide/src/completion/test_utils.rs
@@ -20,7 +20,7 @@ pub(crate) fn do_completion_with_options(
     } else {
         single_file_with_position(code)
     };
-    let completions = analysis.completions(position, options).unwrap().unwrap();
+    let completions = analysis.completions(options, position).unwrap().unwrap();
     let completion_items: Vec<CompletionItem> = completions.into();
     let mut kind_completions: Vec<CompletionItem> =
         completion_items.into_iter().filter(|c| c.completion_kind == kind).collect();
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index 87a0b80f1..54c2bcc09 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -629,6 +629,7 @@ mod tests {
                             },
                         ],
                         cursor_position: None,
+                        is_snippet: false,
                     },
                 ),
                 severity: Error,
@@ -685,6 +686,7 @@ mod tests {
                         ],
                         file_system_edits: [],
                         cursor_position: None,
+                        is_snippet: false,
                     },
                 ),
                 severity: Error,
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 78149ddfc..66125f2f5 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -82,7 +82,7 @@ pub use crate::{
 };
 
 pub use hir::Documentation;
-pub use ra_assists::AssistId;
+pub use ra_assists::{AssistConfig, AssistId};
 pub use ra_db::{
     Canceled, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRootId,
 };
@@ -458,17 +458,17 @@ impl Analysis {
     /// Computes completions at the given position.
     pub fn completions(
         &self,
-        position: FilePosition,
         config: &CompletionConfig,
+        position: FilePosition,
     ) -> Cancelable<Option<Vec<CompletionItem>>> {
-        self.with_db(|db| completion::completions(db, position, config).map(Into::into))
+        self.with_db(|db| completion::completions(db, config, position).map(Into::into))
     }
 
     /// Computes assists (aka code actions aka intentions) for the given
     /// position.
-    pub fn assists(&self, frange: FileRange) -> Cancelable<Vec<Assist>> {
+    pub fn assists(&self, config: &AssistConfig, frange: FileRange) -> Cancelable<Vec<Assist>> {
         self.with_db(|db| {
-            ra_assists::Assist::resolved(db, frange)
+            ra_assists::Assist::resolved(db, config, frange)
                 .into_iter()
                 .map(|assist| Assist {
                     id: assist.assist.id,
diff --git a/crates/ra_ide/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index 410dae75c..68a53ad4b 100644
--- a/crates/ra_ide/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
@@ -670,6 +670,7 @@ mod tests {
                         },
                     ],
                     cursor_position: None,
+                    is_snippet: false,
                 },
             },
         )
@@ -722,6 +723,7 @@ mod tests {
                         },
                     ],
                     cursor_position: None,
+                    is_snippet: false,
                 },
             },
         )
@@ -818,6 +820,7 @@ mod tests {
                         },
                     ],
                     cursor_position: None,
+                    is_snippet: false,
                 },
             },
         )
diff --git a/crates/ra_ide/src/runnables.rs b/crates/ra_ide/src/runnables.rs
index fa8a9d92c..131b8f307 100644
--- a/crates/ra_ide/src/runnables.rs
+++ b/crates/ra_ide/src/runnables.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::Semantics;
+use hir::{AsAssocItem, Semantics};
 use itertools::Itertools;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
@@ -65,14 +65,36 @@ fn runnable_fn(sema: &Semantics<RootDatabase>, fn_def: ast::FnDef) -> Option<Run
         RunnableKind::Bin
     } else {
         let test_id = if let Some(module) = sema.to_def(&fn_def).map(|def| def.module(sema.db)) {
-            let path = module
+            let def = sema.to_def(&fn_def)?;
+            let impl_trait_name =
+                def.as_assoc_item(sema.db).and_then(|assoc_item| {
+                    match assoc_item.container(sema.db) {
+                        hir::AssocItemContainer::Trait(trait_item) => {
+                            Some(trait_item.name(sema.db).to_string())
+                        }
+                        hir::AssocItemContainer::ImplDef(impl_def) => impl_def
+                            .target_ty(sema.db)
+                            .as_adt()
+                            .map(|adt| adt.name(sema.db).to_string()),
+                    }
+                });
+
+            let path_iter = module
                 .path_to_root(sema.db)
                 .into_iter()
                 .rev()
                 .filter_map(|it| it.name(sema.db))
-                .map(|name| name.to_string())
-                .chain(std::iter::once(name_string))
-                .join("::");
+                .map(|name| name.to_string());
+
+            let path = if let Some(impl_trait_name) = impl_trait_name {
+                path_iter
+                    .chain(std::iter::once(impl_trait_name))
+                    .chain(std::iter::once(name_string))
+                    .join("::")
+            } else {
+                path_iter.chain(std::iter::once(name_string)).join("::")
+            };
+
             TestId::Path(path)
         } else {
             TestId::Name(name_string)
@@ -238,6 +260,44 @@ mod tests {
     }
 
     #[test]
+    fn test_runnables_doc_test_in_impl() {
+        let (analysis, pos) = analysis_and_position(
+            r#"
+        //- /lib.rs
+        <|> //empty
+        fn main() {}
+
+        struct Data;
+        impl Data {
+            /// ```
+            /// let x = 5;
+            /// ```
+            fn foo() {}
+        }
+        "#,
+        );
+        let runnables = analysis.runnables(pos.file_id).unwrap();
+        assert_debug_snapshot!(&runnables,
+        @r###"
+        [
+            Runnable {
+                range: 1..21,
+                kind: Bin,
+            },
+            Runnable {
+                range: 51..105,
+                kind: DocTest {
+                    test_id: Path(
+                        "Data::foo",
+                    ),
+                },
+            },
+        ]
+        "###
+                );
+    }
+
+    #[test]
     fn test_runnables_module() {
         let (analysis, pos) = analysis_and_position(
             r#"
diff --git a/crates/ra_ide_db/src/source_change.rs b/crates/ra_ide_db/src/source_change.rs
index af81a91a4..c64165f3a 100644
--- a/crates/ra_ide_db/src/source_change.rs
+++ b/crates/ra_ide_db/src/source_change.rs
@@ -13,6 +13,7 @@ pub struct SourceChange {
     pub source_file_edits: Vec<SourceFileEdit>,
     pub file_system_edits: Vec<FileSystemEdit>,
     pub cursor_position: Option<FilePosition>,
+    pub is_snippet: bool,
 }
 
 impl SourceChange {
@@ -28,6 +29,7 @@ impl SourceChange {
             source_file_edits,
             file_system_edits,
             cursor_position: None,
+            is_snippet: false,
         }
     }
 
@@ -41,6 +43,7 @@ impl SourceChange {
             source_file_edits: edits,
             file_system_edits: vec![],
             cursor_position: None,
+            is_snippet: false,
         }
     }
 
@@ -52,6 +55,7 @@ impl SourceChange {
             source_file_edits: vec![],
             file_system_edits: edits,
             cursor_position: None,
+            is_snippet: false,
         }
     }
 
@@ -115,6 +119,7 @@ impl SingleFileChange {
             source_file_edits: vec![SourceFileEdit { file_id, edit: self.edit }],
             file_system_edits: Vec::new(),
             cursor_position: self.cursor_position.map(|offset| FilePosition { file_id, offset }),
+            is_snippet: false,
         }
     }
 }
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 2a8dac757..664894d1f 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -266,6 +266,15 @@ impl<'a> SyntaxRewriter<'a> {
         let replacement = Replacement::Single(with.clone().into());
         self.replacements.insert(what, replacement);
     }
+    pub fn replace_with_many<T: Clone + Into<SyntaxElement>>(
+        &mut self,
+        what: &T,
+        with: Vec<SyntaxElement>,
+    ) {
+        let what = what.clone().into();
+        let replacement = Replacement::Many(with);
+        self.replacements.insert(what, replacement);
+    }
     pub fn replace_ast<T: AstNode>(&mut self, what: &T, with: &T) {
         self.replace(what.syntax(), with.syntax())
     }
@@ -302,31 +311,41 @@ impl<'a> SyntaxRewriter<'a> {
 
     fn rewrite_children(&self, node: &SyntaxNode) -> SyntaxNode {
         //  FIXME: this could be made much faster.
-        let new_children =
-            node.children_with_tokens().flat_map(|it| self.rewrite_self(&it)).collect::<Vec<_>>();
+        let mut new_children = Vec::new();
+        for child in node.children_with_tokens() {
+            self.rewrite_self(&mut new_children, &child);
+        }
         with_children(node, new_children)
     }
 
     fn rewrite_self(
         &self,
+        acc: &mut Vec<NodeOrToken<rowan::GreenNode, rowan::GreenToken>>,
         element: &SyntaxElement,
-    ) -> Option<NodeOrToken<rowan::GreenNode, rowan::GreenToken>> {
+    ) {
         if let Some(replacement) = self.replacement(&element) {
-            return match replacement {
+            match replacement {
                 Replacement::Single(NodeOrToken::Node(it)) => {
-                    Some(NodeOrToken::Node(it.green().clone()))
+                    acc.push(NodeOrToken::Node(it.green().clone()))
                 }
                 Replacement::Single(NodeOrToken::Token(it)) => {
-                    Some(NodeOrToken::Token(it.green().clone()))
+                    acc.push(NodeOrToken::Token(it.green().clone()))
                 }
-                Replacement::Delete => None,
+                Replacement::Many(replacements) => {
+                    acc.extend(replacements.iter().map(|it| match it {
+                        NodeOrToken::Node(it) => NodeOrToken::Node(it.green().clone()),
+                        NodeOrToken::Token(it) => NodeOrToken::Token(it.green().clone()),
+                    }))
+                }
+                Replacement::Delete => (),
             };
+            return;
         }
         let res = match element {
             NodeOrToken::Token(it) => NodeOrToken::Token(it.green().clone()),
             NodeOrToken::Node(it) => NodeOrToken::Node(self.rewrite_children(it).green().clone()),
         };
-        Some(res)
+        acc.push(res)
     }
 }
 
@@ -341,6 +360,7 @@ impl ops::AddAssign for SyntaxRewriter<'_> {
 enum Replacement {
     Delete,
     Single(SyntaxElement),
+    Many(Vec<SyntaxElement>),
 }
 
 fn with_children(
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
index 24a1e1d91..29eb3fcb9 100644
--- a/crates/ra_syntax/src/ast/edit.rs
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -1,7 +1,10 @@
 //! This module contains functions for editing syntax trees. As the trees are
 //! immutable, all function here return a fresh copy of the tree, instead of
 //! doing an in-place modification.
-use std::{iter, ops::RangeInclusive};
+use std::{
+    fmt, iter,
+    ops::{self, RangeInclusive},
+};
 
 use arrayvec::ArrayVec;
 
@@ -437,6 +440,28 @@ impl From<u8> for IndentLevel {
     }
 }
 
+impl fmt::Display for IndentLevel {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let spaces = "                                        ";
+        let buf;
+        let len = self.0 as usize * 4;
+        let indent = if len <= spaces.len() {
+            &spaces[..len]
+        } else {
+            buf = iter::repeat(' ').take(len).collect::<String>();
+            &buf
+        };
+        fmt::Display::fmt(indent, f)
+    }
+}
+
+impl ops::Add<u8> for IndentLevel {
+    type Output = IndentLevel;
+    fn add(self, rhs: u8) -> IndentLevel {
+        IndentLevel(self.0 + rhs)
+    }
+}
+
 impl IndentLevel {
     pub fn from_node(node: &SyntaxNode) -> IndentLevel {
         let first_token = match node.first_token() {
@@ -453,6 +478,14 @@ impl IndentLevel {
         IndentLevel(0)
     }
 
+    /// XXX: this intentionally doesn't change the indent of the very first token.
+    /// Ie, in something like
+    /// ```
+    /// fn foo() {
+    ///    92
+    /// }
+    /// ```
+    /// if you indent the block, the `{` token would stay put.
     fn increase_indent(self, node: SyntaxNode) -> SyntaxNode {
         let mut rewriter = SyntaxRewriter::default();
         node.descendants_with_tokens()
@@ -463,12 +496,7 @@ impl IndentLevel {
                 text.contains('\n')
             })
             .for_each(|ws| {
-                let new_ws = make::tokens::whitespace(&format!(
-                    "{}{:width$}",
-                    ws.syntax().text(),
-                    "",
-                    width = self.0 as usize * 4
-                ));
+                let new_ws = make::tokens::whitespace(&format!("{}{}", ws.syntax(), self,));
                 rewriter.replace(ws.syntax(), &new_ws)
             });
         rewriter.rewrite(&node)
@@ -485,7 +513,7 @@ impl IndentLevel {
             })
             .for_each(|ws| {
                 let new_ws = make::tokens::whitespace(
-                    &ws.syntax().text().replace(&format!("\n{:1$}", "", self.0 as usize * 4), "\n"),
+                    &ws.syntax().text().replace(&format!("\n{}", self), "\n"),
                 );
                 rewriter.replace(ws.syntax(), &new_ws)
             });
diff --git a/crates/ra_syntax/src/ast/make.rs b/crates/ra_syntax/src/ast/make.rs
index d0e960fb4..da0eb0926 100644
--- a/crates/ra_syntax/src/ast/make.rs
+++ b/crates/ra_syntax/src/ast/make.rs
@@ -1,5 +1,9 @@
 //! This module contains free-standing functions for creating AST fragments out
 //! of smaller pieces.
+//!
+//! Note that all functions here intended to be stupid constructors, which just
+//! assemble a finish node from immediate children. If you want to do something
+//! smarter than that, it probably doesn't belong in this module.
 use itertools::Itertools;
 use stdx::format_to;
 
@@ -95,6 +99,9 @@ pub fn expr_empty_block() -> ast::Expr {
 pub fn expr_unimplemented() -> ast::Expr {
     expr_from_text("unimplemented!()")
 }
+pub fn expr_unreachable() -> ast::Expr {
+    expr_from_text("unreachable!()")
+}
 pub fn expr_todo() -> ast::Expr {
     expr_from_text("todo!()")
 }
@@ -264,10 +271,6 @@ pub fn token(kind: SyntaxKind) -> SyntaxToken {
         .unwrap_or_else(|| panic!("unhandled token: {:?}", kind))
 }
 
-pub fn unreachable_macro_call() -> ast::MacroCall {
-    ast_from_text(&format!("unreachable!()"))
-}
-
 pub fn param(name: String, ty: String) -> ast::Param {
     ast_from_text(&format!("fn f({}: {}) {{ }}", name, ty))
 }
@@ -277,7 +280,12 @@ pub fn param_list(pats: impl IntoIterator<Item = ast::Param>) -> ast::ParamList
     ast_from_text(&format!("fn f({}) {{ }}", args))
 }
 
+pub fn visibility_pub_crate() -> ast::Visibility {
+    ast_from_text("pub(crate) struct S")
+}
+
 pub fn fn_def(
+    visibility: Option<ast::Visibility>,
     fn_name: ast::Name,
     type_params: Option<ast::TypeParamList>,
     params: ast::ParamList,
@@ -285,21 +293,11 @@ pub fn fn_def(
 ) -> ast::FnDef {
     let type_params =
         if let Some(type_params) = type_params { format!("<{}>", type_params) } else { "".into() };
-    ast_from_text(&format!("fn {}{}{} {}", fn_name, type_params, params, body))
-}
-
-pub fn add_leading_newlines(amount_of_newlines: usize, t: impl AstNode) -> ast::SourceFile {
-    let newlines = "\n".repeat(amount_of_newlines);
-    ast_from_text(&format!("{}{}", newlines, t.syntax()))
-}
-
-pub fn add_trailing_newlines(amount_of_newlines: usize, t: impl AstNode) -> ast::SourceFile {
-    let newlines = "\n".repeat(amount_of_newlines);
-    ast_from_text(&format!("{}{}", t.syntax(), newlines))
-}
-
-pub fn add_pub_crate_modifier(fn_def: ast::FnDef) -> ast::FnDef {
-    ast_from_text(&format!("pub(crate) {}", fn_def))
+    let visibility = match visibility {
+        None => String::new(),
+        Some(it) => format!("{} ", it),
+    };
+    ast_from_text(&format!("{}fn {}{}{} {}", visibility, fn_name, type_params, params, body))
 }
 
 fn ast_from_text<N: AstNode>(text: &str) -> N {
diff --git a/crates/rust-analyzer/src/cli/analysis_bench.rs b/crates/rust-analyzer/src/cli/analysis_bench.rs
index 6147ae207..b20efe98d 100644
--- a/crates/rust-analyzer/src/cli/analysis_bench.rs
+++ b/crates/rust-analyzer/src/cli/analysis_bench.rs
@@ -105,7 +105,7 @@ pub fn analysis_bench(
             if is_completion {
                 let options = CompletionConfig::default();
                 let res = do_work(&mut host, file_id, |analysis| {
-                    analysis.completions(file_position, &options)
+                    analysis.completions(&options, file_position)
                 });
                 if verbosity.is_verbose() {
                     println!("\n{:#?}", res);
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index b5dc6f0fa..d75c48597 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -11,7 +11,7 @@ use std::{ffi::OsString, path::PathBuf};
 
 use lsp_types::ClientCapabilities;
 use ra_flycheck::FlycheckConfig;
-use ra_ide::{CompletionConfig, InlayHintsConfig};
+use ra_ide::{AssistConfig, CompletionConfig, InlayHintsConfig};
 use ra_project_model::CargoConfig;
 use serde::Deserialize;
 
@@ -32,6 +32,7 @@ pub struct Config {
 
     pub inlay_hints: InlayHintsConfig,
     pub completion: CompletionConfig,
+    pub assist: AssistConfig,
     pub call_info_full: bool,
     pub lens: LensConfig,
 }
@@ -136,6 +137,7 @@ impl Default for Config {
                 add_call_argument_snippets: true,
                 ..CompletionConfig::default()
             },
+            assist: AssistConfig::default(),
             call_info_full: true,
             lens: LensConfig::default(),
         }
@@ -273,6 +275,7 @@ impl Config {
             {
                 self.client_caps.code_action_literals = value;
             }
+
             self.completion.allow_snippets(false);
             if let Some(completion) = &doc_caps.completion {
                 if let Some(completion_item) = &completion.completion_item {
@@ -288,5 +291,12 @@ impl Config {
                 self.client_caps.work_done_progress = value;
             }
         }
+
+        self.assist.allow_snippets(false);
+        if let Some(experimental) = &caps.experimental {
+            let enable =
+                experimental.get("snippetTextEdit").and_then(|it| it.as_bool()) == Some(true);
+            self.assist.allow_snippets(enable);
+        }
     }
 }
diff --git a/crates/rust-analyzer/src/diagnostics.rs b/crates/rust-analyzer/src/diagnostics.rs
index 4bdd45a7d..25856c543 100644
--- a/crates/rust-analyzer/src/diagnostics.rs
+++ b/crates/rust-analyzer/src/diagnostics.rs
@@ -3,9 +3,11 @@ pub(crate) mod to_proto;
 
 use std::{collections::HashMap, sync::Arc};
 
-use lsp_types::{CodeActionOrCommand, Diagnostic, Range};
+use lsp_types::{Diagnostic, Range};
 use ra_ide::FileId;
 
+use crate::lsp_ext;
+
 pub type CheckFixes = Arc<HashMap<FileId, Vec<Fix>>>;
 
 #[derive(Debug, Default, Clone)]
@@ -18,13 +20,13 @@ pub struct DiagnosticCollection {
 #[derive(Debug, Clone)]
 pub struct Fix {
     pub range: Range,
-    pub action: CodeActionOrCommand,
+    pub action: lsp_ext::CodeAction,
 }
 
 #[derive(Debug)]
 pub enum DiagnosticTask {
     ClearCheck,
-    AddCheck(FileId, Diagnostic, Vec<CodeActionOrCommand>),
+    AddCheck(FileId, Diagnostic, Vec<lsp_ext::CodeAction>),
     SetNative(FileId, Vec<Diagnostic>),
 }
 
@@ -38,7 +40,7 @@ impl DiagnosticCollection {
         &mut self,
         file_id: FileId,
         diagnostic: Diagnostic,
-        fixes: Vec<CodeActionOrCommand>,
+        fixes: Vec<lsp_ext::CodeAction>,
     ) {
         let diagnostics = self.check.entry(file_id).or_default();
         for existing_diagnostic in diagnostics.iter() {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
index 076b3cf27..96466b5c9 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
+++ b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
@@ -68,9 +68,9 @@ expression: diag
                 kind: Some(
                     "quickfix",
                 ),
-                diagnostics: None,
+                command: None,
                 edit: Some(
-                    WorkspaceEdit {
+                    SnippetWorkspaceEdit {
                         changes: Some(
                             {
                                 "file:///test/src/main.rs": [
@@ -106,8 +106,6 @@ expression: diag
                         document_changes: None,
                     },
                 ),
-                command: None,
-                is_preferred: None,
             },
         ],
     },
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
index 69138c15b..8f962277f 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
+++ b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
@@ -53,9 +53,9 @@ expression: diag
                 kind: Some(
                     "quickfix",
                 ),
-                diagnostics: None,
+                command: None,
                 edit: Some(
-                    WorkspaceEdit {
+                    SnippetWorkspaceEdit {
                         changes: Some(
                             {
                                 "file:///test/driver/subcommand/repl.rs": [
@@ -78,8 +78,6 @@ expression: diag
                         document_changes: None,
                     },
                 ),
-                command: None,
-                is_preferred: None,
             },
         ],
     },
diff --git a/crates/rust-analyzer/src/diagnostics/to_proto.rs b/crates/rust-analyzer/src/diagnostics/to_proto.rs
index eabf4908f..afea59525 100644
--- a/crates/rust-analyzer/src/diagnostics/to_proto.rs
+++ b/crates/rust-analyzer/src/diagnostics/to_proto.rs
@@ -7,13 +7,13 @@ use std::{
 };
 
 use lsp_types::{
-    CodeAction, Diagnostic, DiagnosticRelatedInformation, DiagnosticSeverity, DiagnosticTag,
-    Location, NumberOrString, Position, Range, TextEdit, Url, WorkspaceEdit,
+    Diagnostic, DiagnosticRelatedInformation, DiagnosticSeverity, DiagnosticTag, Location,
+    NumberOrString, Position, Range, TextEdit, Url,
 };
 use ra_flycheck::{Applicability, DiagnosticLevel, DiagnosticSpan, DiagnosticSpanMacroExpansion};
 use stdx::format_to;
 
-use crate::Result;
+use crate::{lsp_ext, Result};
 
 /// Converts a Rust level string to a LSP severity
 fn map_level_to_severity(val: DiagnosticLevel) -> Option<DiagnosticSeverity> {
@@ -110,7 +110,7 @@ fn is_deprecated(rd: &ra_flycheck::Diagnostic) -> bool {
 
 enum MappedRustChildDiagnostic {
     Related(DiagnosticRelatedInformation),
-    SuggestedFix(CodeAction),
+    SuggestedFix(lsp_ext::CodeAction),
     MessageLine(String),
 }
 
@@ -143,13 +143,15 @@ fn map_rust_child_diagnostic(
             message: rd.message.clone(),
         })
     } else {
-        MappedRustChildDiagnostic::SuggestedFix(CodeAction {
+        MappedRustChildDiagnostic::SuggestedFix(lsp_ext::CodeAction {
             title: rd.message.clone(),
             kind: Some("quickfix".to_string()),
-            diagnostics: None,
-            edit: Some(WorkspaceEdit::new(edit_map)),
+            edit: Some(lsp_ext::SnippetWorkspaceEdit {
+                // FIXME: there's no good reason to use edit_map here....
+                changes: Some(edit_map),
+                document_changes: None,
+            }),
             command: None,
-            is_preferred: None,
         })
     }
 }
@@ -158,7 +160,7 @@ fn map_rust_child_diagnostic(
 pub(crate) struct MappedRustDiagnostic {
     pub location: Location,
     pub diagnostic: Diagnostic,
-    pub fixes: Vec<CodeAction>,
+    pub fixes: Vec<lsp_ext::CodeAction>,
 }
 
 /// Converts a Rust root diagnostic to LSP form
diff --git a/crates/rust-analyzer/src/lsp_ext.rs b/crates/rust-analyzer/src/lsp_ext.rs
index 313a8c769..f75a26eb7 100644
--- a/crates/rust-analyzer/src/lsp_ext.rs
+++ b/crates/rust-analyzer/src/lsp_ext.rs
@@ -1,6 +1,6 @@
 //! rust-analyzer extensions to the LSP.
 
-use std::path::PathBuf;
+use std::{collections::HashMap, path::PathBuf};
 
 use lsp_types::request::Request;
 use lsp_types::{Location, Position, Range, TextDocumentIdentifier};
@@ -137,7 +137,7 @@ pub struct Runnable {
 #[serde(rename_all = "camelCase")]
 pub struct SourceChange {
     pub label: String,
-    pub workspace_edit: lsp_types::WorkspaceEdit,
+    pub workspace_edit: SnippetWorkspaceEdit,
     pub cursor_position: Option<lsp_types::TextDocumentPositionParams>,
 }
 
@@ -183,3 +183,54 @@ pub struct SsrParams {
     pub query: String,
     pub parse_only: bool,
 }
+
+pub enum CodeActionRequest {}
+
+impl Request for CodeActionRequest {
+    type Params = lsp_types::CodeActionParams;
+    type Result = Option<Vec<CodeAction>>;
+    const METHOD: &'static str = "textDocument/codeAction";
+}
+
+#[derive(Debug, PartialEq, Clone, Default, Deserialize, Serialize)]
+pub struct CodeAction {
+    pub title: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub kind: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub command: Option<lsp_types::Command>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub edit: Option<SnippetWorkspaceEdit>,
+}
+
+#[derive(Debug, Eq, PartialEq, Clone, Default, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SnippetWorkspaceEdit {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub changes: Option<HashMap<lsp_types::Url, Vec<lsp_types::TextEdit>>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub document_changes: Option<Vec<SnippetDocumentChangeOperation>>,
+}
+
+#[derive(Debug, Eq, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(untagged, rename_all = "lowercase")]
+pub enum SnippetDocumentChangeOperation {
+    Op(lsp_types::ResourceOp),
+    Edit(SnippetTextDocumentEdit),
+}
+
+#[derive(Debug, Eq, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SnippetTextDocumentEdit {
+    pub text_document: lsp_types::VersionedTextDocumentIdentifier,
+    pub edits: Vec<SnippetTextEdit>,
+}
+
+#[derive(Debug, Eq, PartialEq, Clone, Default, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SnippetTextEdit {
+    pub range: Range,
+    pub new_text: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub insert_text_format: Option<lsp_types::InsertTextFormat>,
+}
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index 15e5bb354..87795fffb 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -518,6 +518,7 @@ fn on_request(
         .on::<lsp_ext::ParentModule>(handlers::handle_parent_module)?
         .on::<lsp_ext::Runnables>(handlers::handle_runnables)?
         .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)?
+        .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)?
         .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)?
         .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)?
         .on::<lsp_types::request::WorkspaceSymbol>(handlers::handle_workspace_symbol)?
@@ -525,7 +526,6 @@ fn on_request(
         .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)?
         .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)?
         .on::<lsp_types::request::Completion>(handlers::handle_completion)?
-        .on::<lsp_types::request::CodeActionRequest>(handlers::handle_code_action)?
         .on::<lsp_types::request::CodeLensRequest>(handlers::handle_code_lens)?
         .on::<lsp_types::request::CodeLensResolve>(handlers::handle_code_lens_resolve)?
         .on::<lsp_types::request::FoldingRangeRequest>(handlers::handle_folding_range)?
diff --git a/crates/rust-analyzer/src/main_loop/handlers.rs b/crates/rust-analyzer/src/main_loop/handlers.rs
index e67556752..4ff8fa69e 100644
--- a/crates/rust-analyzer/src/main_loop/handlers.rs
+++ b/crates/rust-analyzer/src/main_loop/handlers.rs
@@ -11,12 +11,11 @@ use lsp_server::ErrorCode;
 use lsp_types::{
     CallHierarchyIncomingCall, CallHierarchyIncomingCallsParams, CallHierarchyItem,
     CallHierarchyOutgoingCall, CallHierarchyOutgoingCallsParams, CallHierarchyPrepareParams,
-    CodeAction, CodeActionResponse, CodeLens, Command, CompletionItem, Diagnostic,
-    DocumentFormattingParams, DocumentHighlight, DocumentSymbol, FoldingRange, FoldingRangeParams,
-    Hover, HoverContents, Location, MarkupContent, MarkupKind, Position, PrepareRenameResponse,
-    Range, RenameParams, SemanticTokensParams, SemanticTokensRangeParams,
-    SemanticTokensRangeResult, SemanticTokensResult, SymbolInformation, TextDocumentIdentifier,
-    TextEdit, Url, WorkspaceEdit,
+    CodeLens, Command, CompletionItem, Diagnostic, DocumentFormattingParams, DocumentHighlight,
+    DocumentSymbol, FoldingRange, FoldingRangeParams, Hover, HoverContents, Location,
+    MarkupContent, MarkupKind, Position, PrepareRenameResponse, Range, RenameParams,
+    SemanticTokensParams, SemanticTokensRangeParams, SemanticTokensRangeResult,
+    SemanticTokensResult, SymbolInformation, TextDocumentIdentifier, TextEdit, Url, WorkspaceEdit,
 };
 use ra_ide::{
     Assist, FileId, FilePosition, FileRange, Query, RangeInfo, Runnable, RunnableKind, SearchScope,
@@ -476,7 +475,7 @@ pub fn handle_completion(
         return Ok(None);
     }
 
-    let items = match world.analysis().completions(position, &world.config.completion)? {
+    let items = match world.analysis().completions(&world.config.completion, position)? {
         None => return Ok(None),
         Some(items) => items,
     };
@@ -585,9 +584,8 @@ pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Optio
         None => return Ok(None),
         Some(it) => it.info,
     };
-
-    let source_change = to_proto::source_change(&world, source_change)?;
-    Ok(Some(source_change.workspace_edit))
+    let workspace_edit = to_proto::workspace_edit(&world, source_change)?;
+    Ok(Some(workspace_edit))
 }
 
 pub fn handle_references(
@@ -696,14 +694,21 @@ pub fn handle_formatting(
 pub fn handle_code_action(
     world: WorldSnapshot,
     params: lsp_types::CodeActionParams,
-) -> Result<Option<CodeActionResponse>> {
+) -> Result<Option<Vec<lsp_ext::CodeAction>>> {
     let _p = profile("handle_code_action");
+    // We intentionally don't support command-based actions, as those either
+    // requires custom client-code anyway, or requires server-initiated edits.
+    // Server initiated edits break causality, so we avoid those as well.
+    if !world.config.client_caps.code_action_literals {
+        return Ok(None);
+    }
+
     let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
     let line_index = world.analysis().file_line_index(file_id)?;
     let range = from_proto::text_range(&line_index, params.range);
 
     let diagnostics = world.analysis().diagnostics(file_id)?;
-    let mut res = CodeActionResponse::default();
+    let mut res: Vec<lsp_ext::CodeAction> = Vec::new();
 
     let fixes_from_diagnostics = diagnostics
         .into_iter()
@@ -713,22 +718,9 @@ pub fn handle_code_action(
 
     for source_edit in fixes_from_diagnostics {
         let title = source_edit.label.clone();
-        let edit = to_proto::source_change(&world, source_edit)?;
-
-        let command = Command {
-            title,
-            command: "rust-analyzer.applySourceChange".to_string(),
-            arguments: Some(vec![to_value(edit).unwrap()]),
-        };
-        let action = CodeAction {
-            title: command.title.clone(),
-            kind: None,
-            diagnostics: None,
-            edit: None,
-            command: Some(command),
-            is_preferred: None,
-        };
-        res.push(action.into());
+        let edit = to_proto::snippet_workspace_edit(&world, source_edit)?;
+        let action = lsp_ext::CodeAction { title, kind: None, edit: Some(edit), command: None };
+        res.push(action);
     }
 
     for fix in world.check_fixes.get(&file_id).into_iter().flatten() {
@@ -740,14 +732,21 @@ pub fn handle_code_action(
     }
 
     let mut grouped_assists: FxHashMap<String, (usize, Vec<Assist>)> = FxHashMap::default();
-    for assist in world.analysis().assists(FileRange { file_id, range })?.into_iter() {
+    for assist in
+        world.analysis().assists(&world.config.assist, FileRange { file_id, range })?.into_iter()
+    {
         match &assist.group_label {
             Some(label) => grouped_assists
                 .entry(label.to_owned())
                 .or_insert_with(|| {
                     let idx = res.len();
-                    let dummy = Command::new(String::new(), String::new(), None);
-                    res.push(dummy.into());
+                    let dummy = lsp_ext::CodeAction {
+                        title: String::new(),
+                        kind: None,
+                        command: None,
+                        edit: None,
+                    };
+                    res.push(dummy);
                     (idx, Vec::new())
                 })
                 .1
@@ -775,35 +774,10 @@ pub fn handle_code_action(
                 command: "rust-analyzer.selectAndApplySourceChange".to_string(),
                 arguments: Some(vec![serde_json::Value::Array(arguments)]),
             });
-            res[idx] = CodeAction {
-                title,
-                kind: None,
-                diagnostics: None,
-                edit: None,
-                command,
-                is_preferred: None,
-            }
-            .into();
+            res[idx] = lsp_ext::CodeAction { title, kind: None, edit: None, command };
         }
     }
 
-    // If the client only supports commands then filter the list
-    // and remove and actions that depend on edits.
-    if !world.config.client_caps.code_action_literals {
-        // FIXME: use drain_filter once it hits stable.
-        res = res
-            .into_iter()
-            .filter_map(|it| match it {
-                cmd @ lsp_types::CodeActionOrCommand::Command(_) => Some(cmd),
-                lsp_types::CodeActionOrCommand::CodeAction(action) => match action.command {
-                    Some(cmd) if action.edit.is_none() => {
-                        Some(lsp_types::CodeActionOrCommand::Command(cmd))
-                    }
-                    _ => None,
-                },
-            })
-            .collect();
-    }
     Ok(Some(res))
 }
 
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index a8e2e535f..af54f81b7 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -112,6 +112,22 @@ pub(crate) fn text_edit(
     lsp_types::TextEdit { range, new_text }
 }
 
+pub(crate) fn snippet_text_edit(
+    line_index: &LineIndex,
+    line_endings: LineEndings,
+    is_snippet: bool,
+    indel: Indel,
+) -> lsp_ext::SnippetTextEdit {
+    let text_edit = text_edit(line_index, line_endings, indel);
+    let insert_text_format =
+        if is_snippet { Some(lsp_types::InsertTextFormat::Snippet) } else { None };
+    lsp_ext::SnippetTextEdit {
+        range: text_edit.range,
+        new_text: text_edit.new_text,
+        insert_text_format,
+    }
+}
+
 pub(crate) fn text_edit_vec(
     line_index: &LineIndex,
     line_endings: LineEndings,
@@ -441,10 +457,11 @@ pub(crate) fn goto_definition_response(
     }
 }
 
-pub(crate) fn text_document_edit(
+pub(crate) fn snippet_text_document_edit(
     world: &WorldSnapshot,
+    is_snippet: bool,
     source_file_edit: SourceFileEdit,
-) -> Result<lsp_types::TextDocumentEdit> {
+) -> Result<lsp_ext::SnippetTextDocumentEdit> {
     let text_document = versioned_text_document_identifier(world, source_file_edit.file_id, None)?;
     let line_index = world.analysis().file_line_index(source_file_edit.file_id)?;
     let line_endings = world.file_line_endings(source_file_edit.file_id);
@@ -452,9 +469,9 @@ pub(crate) fn text_document_edit(
         .edit
         .as_indels()
         .iter()
-        .map(|it| text_edit(&line_index, line_endings, it.clone()))
+        .map(|it| snippet_text_edit(&line_index, line_endings, is_snippet, it.clone()))
         .collect();
-    Ok(lsp_types::TextDocumentEdit { text_document, edits })
+    Ok(lsp_ext::SnippetTextDocumentEdit { text_document, edits })
 }
 
 pub(crate) fn resource_op(
@@ -500,20 +517,70 @@ pub(crate) fn source_change(
             })
         }
     };
-    let mut document_changes: Vec<lsp_types::DocumentChangeOperation> = Vec::new();
+    let label = source_change.label.clone();
+    let workspace_edit = self::snippet_workspace_edit(world, source_change)?;
+    Ok(lsp_ext::SourceChange { label, workspace_edit, cursor_position })
+}
+
+pub(crate) fn snippet_workspace_edit(
+    world: &WorldSnapshot,
+    source_change: SourceChange,
+) -> Result<lsp_ext::SnippetWorkspaceEdit> {
+    let mut document_changes: Vec<lsp_ext::SnippetDocumentChangeOperation> = Vec::new();
     for op in source_change.file_system_edits {
         let op = resource_op(&world, op)?;
-        document_changes.push(lsp_types::DocumentChangeOperation::Op(op));
+        document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Op(op));
     }
     for edit in source_change.source_file_edits {
-        let edit = text_document_edit(&world, edit)?;
-        document_changes.push(lsp_types::DocumentChangeOperation::Edit(edit));
+        let edit = snippet_text_document_edit(&world, source_change.is_snippet, edit)?;
+        document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Edit(edit));
+    }
+    let workspace_edit =
+        lsp_ext::SnippetWorkspaceEdit { changes: None, document_changes: Some(document_changes) };
+    Ok(workspace_edit)
+}
+
+pub(crate) fn workspace_edit(
+    world: &WorldSnapshot,
+    source_change: SourceChange,
+) -> Result<lsp_types::WorkspaceEdit> {
+    assert!(!source_change.is_snippet);
+    snippet_workspace_edit(world, source_change).map(|it| it.into())
+}
+
+impl From<lsp_ext::SnippetWorkspaceEdit> for lsp_types::WorkspaceEdit {
+    fn from(snippet_workspace_edit: lsp_ext::SnippetWorkspaceEdit) -> lsp_types::WorkspaceEdit {
+        lsp_types::WorkspaceEdit {
+            changes: None,
+            document_changes: snippet_workspace_edit.document_changes.map(|changes| {
+                lsp_types::DocumentChanges::Operations(
+                    changes
+                        .into_iter()
+                        .map(|change| match change {
+                            lsp_ext::SnippetDocumentChangeOperation::Op(op) => {
+                                lsp_types::DocumentChangeOperation::Op(op)
+                            }
+                            lsp_ext::SnippetDocumentChangeOperation::Edit(edit) => {
+                                lsp_types::DocumentChangeOperation::Edit(
+                                    lsp_types::TextDocumentEdit {
+                                        text_document: edit.text_document,
+                                        edits: edit
+                                            .edits
+                                            .into_iter()
+                                            .map(|edit| lsp_types::TextEdit {
+                                                range: edit.range,
+                                                new_text: edit.new_text,
+                                            })
+                                            .collect(),
+                                    },
+                                )
+                            }
+                        })
+                        .collect(),
+                )
+            }),
+        }
     }
-    let workspace_edit = lsp_types::WorkspaceEdit {
-        changes: None,
-        document_changes: Some(lsp_types::DocumentChanges::Operations(document_changes)),
-    };
-    Ok(lsp_ext::SourceChange { label: source_change.label, workspace_edit, cursor_position })
 }
 
 pub fn call_hierarchy_item(
@@ -571,22 +638,26 @@ fn main() <fold>{
     }
 }
 
-pub(crate) fn code_action(world: &WorldSnapshot, assist: Assist) -> Result<lsp_types::CodeAction> {
-    let source_change = source_change(&world, assist.source_change)?;
-    let arg = serde_json::to_value(source_change)?;
-    let title = assist.label;
-    let command = lsp_types::Command {
-        title: title.clone(),
-        command: "rust-analyzer.applySourceChange".to_string(),
-        arguments: Some(vec![arg]),
-    };
+pub(crate) fn code_action(world: &WorldSnapshot, assist: Assist) -> Result<lsp_ext::CodeAction> {
+    let res = if assist.source_change.cursor_position.is_none() {
+        lsp_ext::CodeAction {
+            title: assist.label,
+            kind: Some(String::new()),
+            edit: Some(snippet_workspace_edit(world, assist.source_change)?),
+            command: None,
+        }
+    } else {
+        assert!(!assist.source_change.is_snippet);
+        let source_change = source_change(&world, assist.source_change)?;
+        let arg = serde_json::to_value(source_change)?;
+        let title = assist.label;
+        let command = lsp_types::Command {
+            title: title.clone(),
+            command: "rust-analyzer.applySourceChange".to_string(),
+            arguments: Some(vec![arg]),
+        };
 
-    Ok(lsp_types::CodeAction {
-        title,
-        kind: Some(String::new()),
-        diagnostics: None,
-        edit: None,
-        command: Some(command),
-        is_preferred: None,
-    })
+        lsp_ext::CodeAction { title, kind: Some(String::new()), edit: None, command: Some(command) }
+    };
+    Ok(res)
 }
diff --git a/crates/rust-analyzer/tests/heavy_tests/main.rs b/crates/rust-analyzer/tests/heavy_tests/main.rs
index 5011cc273..74676b3ee 100644
--- a/crates/rust-analyzer/tests/heavy_tests/main.rs
+++ b/crates/rust-analyzer/tests/heavy_tests/main.rs
@@ -333,29 +333,17 @@ fn main() {}
             partial_result_params: PartialResultParams::default(),
             work_done_progress_params: WorkDoneProgressParams::default(),
         },
-        json!([
-          {
-            "command": {
-              "arguments": [
+        json!([{
+            "edit": {
+              "documentChanges": [
                 {
-                  "cursorPosition": null,
-                  "label": "Create module",
-                  "workspaceEdit": {
-                    "documentChanges": [
-                      {
-                        "kind": "create",
-                        "uri": "file:///[..]/src/bar.rs"
-                      }
-                    ]
-                  }
+                  "kind": "create",
+                  "uri": "file:///[..]/src/bar.rs"
                 }
-              ],
-              "command": "rust-analyzer.applySourceChange",
-              "title": "Create module"
+              ]
             },
             "title": "Create module"
-          }
-        ]),
+        }]),
     );
 
     server.request::<CodeActionRequest>(
@@ -416,29 +404,17 @@ fn main() {{}}
             partial_result_params: PartialResultParams::default(),
             work_done_progress_params: WorkDoneProgressParams::default(),
         },
-        json!([
-          {
-            "command": {
-              "arguments": [
+        json!([{
+            "edit": {
+              "documentChanges": [
                 {
-                  "cursorPosition": null,
-                  "label": "Create module",
-                  "workspaceEdit": {
-                    "documentChanges": [
-                      {
-                        "kind": "create",
-                        "uri": "file:///[..]/src/bar.rs"
-                      }
-                    ]
-                  }
+                  "kind": "create",
+                  "uri": "file://[..]/src/bar.rs"
                 }
-              ],
-              "command": "rust-analyzer.applySourceChange",
-              "title": "Create module"
+              ]
             },
             "title": "Create module"
-          }
-        ]),
+        }]),
     );
 
     server.request::<CodeActionRequest>(
diff --git a/crates/stdx/src/lib.rs b/crates/stdx/src/lib.rs
index 0f34ce70e..71a57fba2 100644
--- a/crates/stdx/src/lib.rs
+++ b/crates/stdx/src/lib.rs
@@ -116,3 +116,11 @@ pub fn to_lower_snake_case(s: &str) -> String {
     }
     buf
 }
+
+pub fn replace(buf: &mut String, from: char, to: &str) {
+    if !buf.contains(from) {
+        return;
+    }
+    // FIXME: do this in place.
+    *buf = buf.replace(from, to)
+}
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
new file mode 100644
index 000000000..d2ec6c021
--- /dev/null
+++ b/docs/dev/lsp-extensions.md
@@ -0,0 +1,34 @@
+# LSP Extensions
+
+This document describes LSP extensions used by rust-analyzer.
+It's a best effort document, when in doubt, consult the source (and send a PR with clarification ;-) ).
+We aim to upstream all non Rust-specific extensions to the protocol, but this is not a top priority.
+All capabilities are enabled via `experimental` field of `ClientCapabilities`.
+
+## `SnippetTextEdit`
+
+**Capability**
+
+```typescript
+{
+    "snippetTextEdit": boolean
+}
+```
+
+If this capability is set, `WorkspaceEdit`s returned from `codeAction` requests might contain `SnippetTextEdit`s instead of usual `TextEdit`s:
+
+```typescript
+interface SnippetTextEdit extends TextEdit {
+    insertTextFormat?: InsertTextFormat;
+}
+```
+
+```typescript
+export interface TextDocumentEdit {
+        textDocument: VersionedTextDocumentIdentifier;
+        edits: (TextEdit | SnippetTextEdit)[];
+}
+```
+
+When applying such code action, the editor should insert snippet, with tab stops and placeholder.
+At the moment, rust-analyzer guarantees that only a single edit will have `InsertTextFormat.Snippet`.
diff --git a/docs/user/assists.md b/docs/user/assists.md
index 692fd4f52..f329fcc10 100644
--- a/docs/user/assists.md
+++ b/docs/user/assists.md
@@ -17,7 +17,7 @@ struct S;
 struct S;
 
 impl Debug for S {
-
+    $0
 }
 ```
 
@@ -33,7 +33,7 @@ struct Point {
 }
 
 // AFTER
-#[derive()]
+#[derive($0)]
 struct Point {
     x: u32,
     y: u32,
@@ -77,7 +77,7 @@ fn foo() {
 }
 
 fn bar(arg: &str, baz: Baz) {
-    todo!()
+    ${0:todo!()}
 }
 
 ```
@@ -105,16 +105,16 @@ Adds a new inherent impl for a type.
 ```rust
 // BEFORE
 struct Ctx<T: Clone> {
-     data: T,┃
+    data: T,┃
 }
 
 // AFTER
 struct Ctx<T: Clone> {
-     data: T,
+    data: T,
 }
 
 impl<T: Clone> Ctx<T> {
-
+    $0
 }
 ```
 
@@ -146,7 +146,7 @@ trait Trait {
 impl Trait for () {
     Type X = ();
     fn foo(&self) {}
-    fn bar(&self) {}
+    $0fn bar(&self) {}
 
 }
 ```
@@ -176,7 +176,7 @@ trait Trait<T> {
 
 impl Trait<u32> for () {
     fn foo(&self) -> u32 {
-        todo!()
+        ${0:todo!()}
     }
 
 }
@@ -203,6 +203,24 @@ impl<T: Clone> Ctx<T> {
 
 ```
 
+## `add_turbo_fish`
+
+Adds `::<_>` to a call of a generic method or function.
+
+```rust
+// BEFORE
+fn make<T>() -> T { todo!() }
+fn main() {
+    let x = make┃();
+}
+
+// AFTER
+fn make<T>() -> T { todo!() }
+fn main() {
+    let x = make::<${0:_}>();
+}
+```
+
 ## `apply_demorgan`
 
 Apply [De Morgan's law](https://en.wikipedia.org/wiki/De_Morgan%27s_laws).
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index cffdcf11a..fac1a0be3 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -31,24 +31,79 @@ export function createClient(serverPath: string, cwd: string): lc.LanguageClient
                 const res = await next(document, token);
                 if (res === undefined) throw new Error('busy');
                 return res;
+            },
+            async provideCodeActions(document: vscode.TextDocument, range: vscode.Range, context: vscode.CodeActionContext, token: vscode.CancellationToken, _next: lc.ProvideCodeActionsSignature) {
+                const params: lc.CodeActionParams = {
+                    textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(document),
+                    range: client.code2ProtocolConverter.asRange(range),
+                    context: client.code2ProtocolConverter.asCodeActionContext(context)
+                };
+                return client.sendRequest(lc.CodeActionRequest.type, params, token).then((values) => {
+                    if (values === null) return undefined;
+                    const result: (vscode.CodeAction | vscode.Command)[] = [];
+                    for (const item of values) {
+                        if (lc.CodeAction.is(item)) {
+                            const action = client.protocol2CodeConverter.asCodeAction(item);
+                            if (isSnippetEdit(item)) {
+                                action.command = {
+                                    command: "rust-analyzer.applySnippetWorkspaceEdit",
+                                    title: "",
+                                    arguments: [action.edit],
+                                };
+                                action.edit = undefined;
+                            }
+                            result.push(action);
+                        } else {
+                            const command = client.protocol2CodeConverter.asCommand(item);
+                            result.push(command);
+                        }
+                    }
+                    return result;
+                },
+                    (_error) => undefined
+                );
             }
+
         } as any
     };
 
-    const res = new lc.LanguageClient(
+    const client = new lc.LanguageClient(
         'rust-analyzer',
         'Rust Analyzer Language Server',
         serverOptions,
         clientOptions,
     );
 
-    // To turn on all proposed features use: res.registerProposedFeatures();
+    // To turn on all proposed features use: client.registerProposedFeatures();
     // Here we want to enable CallHierarchyFeature and SemanticTokensFeature
     // since they are available on stable.
     // Note that while these features are stable in vscode their LSP protocol
     // implementations are still in the "proposed" category for 3.16.
-    res.registerFeature(new CallHierarchyFeature(res));
-    res.registerFeature(new SemanticTokensFeature(res));
+    client.registerFeature(new CallHierarchyFeature(client));
+    client.registerFeature(new SemanticTokensFeature(client));
+    client.registerFeature(new SnippetTextEditFeature());
+
+    return client;
+}
 
-    return res;
+class SnippetTextEditFeature implements lc.StaticFeature {
+    fillClientCapabilities(capabilities: lc.ClientCapabilities): void {
+        const caps: any = capabilities.experimental ?? {};
+        caps.snippetTextEdit = true;
+        capabilities.experimental = caps;
+    }
+    initialize(_capabilities: lc.ServerCapabilities<any>, _documentSelector: lc.DocumentSelector | undefined): void {
+    }
+}
+
+function isSnippetEdit(action: lc.CodeAction): boolean {
+    const documentChanges = action.edit?.documentChanges ?? [];
+    for (const edit of documentChanges) {
+        if (lc.TextDocumentEdit.is(edit)) {
+            if (edit.edits.some((indel) => (indel as any).insertTextFormat === lc.InsertTextFormat.Snippet)) {
+                return true;
+            }
+        }
+    }
+    return false;
 }
diff --git a/editors/code/src/commands/index.ts b/editors/code/src/commands/index.ts
index bdb7fc3b0..0937b495c 100644
--- a/editors/code/src/commands/index.ts
+++ b/editors/code/src/commands/index.ts
@@ -4,6 +4,7 @@ import * as ra from '../rust-analyzer-api';
 
 import { Ctx, Cmd } from '../ctx';
 import * as sourceChange from '../source_change';
+import { assert } from '../util';
 
 export * from './analyzer_status';
 export * from './matching_brace';
@@ -51,3 +52,37 @@ export function selectAndApplySourceChange(ctx: Ctx): Cmd {
         }
     };
 }
+
+export function applySnippetWorkspaceEdit(_ctx: Ctx): Cmd {
+    return async (edit: vscode.WorkspaceEdit) => {
+        assert(edit.entries().length === 1, `bad ws edit: ${JSON.stringify(edit)}`);
+        const [uri, edits] = edit.entries()[0];
+
+        const editor = vscode.window.visibleTextEditors.find((it) => it.document.uri.toString() === uri.toString());
+        if (!editor) return;
+
+        let editWithSnippet: vscode.TextEdit | undefined = undefined;
+        let lineDelta = 0;
+        await editor.edit((builder) => {
+            for (const indel of edits) {
+                const isSnippet = indel.newText.indexOf('$0') !== -1 || indel.newText.indexOf('${') !== -1;
+                if (isSnippet) {
+                    editWithSnippet = indel;
+                } else {
+                    if (!editWithSnippet) {
+                        lineDelta = (indel.newText.match(/\n/g) || []).length - (indel.range.end.line - indel.range.start.line);
+                    }
+                    builder.replace(indel.range, indel.newText);
+                }
+            }
+        });
+        if (editWithSnippet) {
+            const snip = editWithSnippet as vscode.TextEdit;
+            const range = snip.range.with(
+                snip.range.start.with(snip.range.start.line + lineDelta),
+                snip.range.end.with(snip.range.end.line + lineDelta),
+            );
+            await editor.insertSnippet(new vscode.SnippetString(snip.newText), range);
+        }
+    };
+}
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index c015460b8..ac3bb365e 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -91,6 +91,7 @@ export async function activate(context: vscode.ExtensionContext) {
     ctx.registerCommand('debugSingle', commands.debugSingle);
     ctx.registerCommand('showReferences', commands.showReferences);
     ctx.registerCommand('applySourceChange', commands.applySourceChange);
+    ctx.registerCommand('applySnippetWorkspaceEdit', commands.applySnippetWorkspaceEdit);
     ctx.registerCommand('selectAndApplySourceChange', commands.selectAndApplySourceChange);
 
     ctx.pushCleanup(activateTaskProvider(workspaceFolder));
diff --git a/xtask/tests/tidy.rs b/xtask/tests/tidy.rs
index b8e8860ba..2e9fcf07c 100644
--- a/xtask/tests/tidy.rs
+++ b/xtask/tests/tidy.rs
@@ -57,6 +57,7 @@ fn check_todo(path: &Path, text: &str) {
         "tests/generated.rs",
         "handlers/add_missing_impl_members.rs",
         "handlers/add_function.rs",
+        "handlers/add_turbo_fish.rs",
         // To support generating `todo!()` in assists, we have `expr_todo()` in ast::make.
         "ast/make.rs",
     ];