Merge branch 'master' of github.com:rust-analyzer/rust-analyzer into fix_4202

11 files changed, 604 insertions, 179 deletions

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 03806724a..49deb6701 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
@@ -1,11 +1,12 @@
+use ra_ide_db::RootDatabase;
 use ra_syntax::{
     ast::{self, AstNode, NameOwner},
     TextSize,
 };
 use stdx::format_to;
 
-use crate::{Assist, AssistCtx, AssistId};
-use ra_ide_db::RootDatabase;
+use crate::{utils::FamousDefs, Assist, AssistCtx, AssistId};
+use test_utils::tested_by;
 
 // Assist add_from_impl_for_enum
 //
@@ -41,7 +42,8 @@ pub(crate) fn add_from_impl_for_enum(ctx: AssistCtx) -> Option<Assist> {
         _ => return None,
     };
 
-    if already_has_from_impl(ctx.sema, &variant) {
+    if existing_from_impl(ctx.sema, &variant).is_some() {
+        tested_by!(test_add_from_impl_already_exists);
         return None;
     }
 
@@ -70,41 +72,33 @@ impl From<{0}> for {1} {{
     )
 }
 
-fn already_has_from_impl(
+fn existing_from_impl(
     sema: &'_ hir::Semantics<'_, RootDatabase>,
     variant: &ast::EnumVariant,
-) -> bool {
-    let scope = sema.scope(&variant.syntax());
+) -> Option<()> {
+    let variant = sema.to_def(variant)?;
+    let enum_ = variant.parent_enum(sema.db);
+    let krate = enum_.module(sema.db).krate();
 
-    let from_path = ast::make::path_from_text("From");
-    let from_hir_path = match hir::Path::from_ast(from_path) {
-        Some(p) => p,
-        None => return false,
-    };
-    let from_trait = match scope.resolve_hir_path(&from_hir_path) {
-        Some(hir::PathResolution::Def(hir::ModuleDef::Trait(t))) => t,
-        _ => return false,
-    };
+    let from_trait = FamousDefs(sema, krate).core_convert_From()?;
 
-    let e: hir::Enum = match sema.to_def(&variant.parent_enum()) {
-        Some(e) => e,
-        None => return false,
-    };
-    let e_ty = e.ty(sema.db);
+    let enum_type = enum_.ty(sema.db);
 
-    let hir_enum_var: hir::EnumVariant = match sema.to_def(variant) {
-        Some(ev) => ev,
-        None => return false,
-    };
-    let var_ty = hir_enum_var.fields(sema.db)[0].signature_ty(sema.db);
+    let wrapped_type = variant.fields(sema.db).get(0)?.signature_ty(sema.db);
 
-    e_ty.impls_trait(sema.db, from_trait, &[var_ty])
+    if enum_type.impls_trait(sema.db, from_trait, &[wrapped_type]) {
+        Some(())
+    } else {
+        None
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+
     use crate::helpers::{check_assist, check_assist_not_applicable};
+    use test_utils::covers;
 
     #[test]
     fn test_add_from_impl_for_enum() {
@@ -136,36 +130,40 @@ mod tests {
         );
     }
 
+    fn check_not_applicable(ra_fixture: &str) {
+        let fixture =
+            format!("//- main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
+        check_assist_not_applicable(add_from_impl_for_enum, &fixture)
+    }
+
     #[test]
     fn test_add_from_impl_no_element() {
-        check_assist_not_applicable(add_from_impl_for_enum, "enum A { <|>One }");
+        check_not_applicable("enum A { <|>One }");
     }
 
     #[test]
     fn test_add_from_impl_more_than_one_element_in_tuple() {
-        check_assist_not_applicable(add_from_impl_for_enum, "enum A { <|>One(u32, String) }");
+        check_not_applicable("enum A { <|>One(u32, String) }");
     }
 
     #[test]
     fn test_add_from_impl_struct_variant() {
-        check_assist_not_applicable(add_from_impl_for_enum, "enum A { <|>One { x: u32 } }");
+        check_not_applicable("enum A { <|>One { x: u32 } }");
     }
 
     #[test]
     fn test_add_from_impl_already_exists() {
-        check_assist_not_applicable(
-            add_from_impl_for_enum,
-            r#"enum A { <|>One(u32), }
+        covers!(test_add_from_impl_already_exists);
+        check_not_applicable(
+            r#"
+enum A { <|>One(u32), }
 
 impl From<u32> for A {
     fn from(v: u32) -> Self {
         A::One(v)
     }
 }
-
-pub trait From<T> {
-    fn from(T) -> Self;
-}"#,
+"#,
         );
     }
 
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 2d6d44980..e466c9a86 100644
--- a/crates/ra_assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
@@ -1,6 +1,10 @@
 use hir::HasSource;
 use ra_syntax::{
-    ast::{self, edit, make, AstNode, NameOwner},
+    ast::{
+        self,
+        edit::{self, IndentLevel},
+        make, AstNode, NameOwner,
+    },
     SmolStr,
 };
 
@@ -40,7 +44,9 @@ enum AddMissingImplMembersMode {
 // }
 //
 // impl Trait<u32> for () {
-//     fn foo(&self) -> u32 { todo!() }
+//     fn foo(&self) -> u32 {
+//         todo!()
+//     }
 //
 // }
 // ```
@@ -165,7 +171,9 @@ fn add_missing_impl_members_inner(
 
 fn add_body(fn_def: ast::FnDef) -> ast::FnDef {
     if fn_def.body().is_none() {
-        fn_def.with_body(make::block_from_expr(make::expr_todo()))
+        let body = make::block_expr(None, Some(make::expr_todo()));
+        let body = IndentLevel(1).increase_indent(body);
+        fn_def.with_body(body)
     } else {
         fn_def
     }
@@ -181,7 +189,7 @@ mod tests {
     fn test_add_missing_impl_members() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo {
     type Output;
 
@@ -197,8 +205,8 @@ struct S;
 impl Foo for S {
     fn bar(&self) {}
 <|>
-}",
-            "
+}"#,
+            r#"
 trait Foo {
     type Output;
 
@@ -215,10 +223,14 @@ impl Foo for S {
     fn bar(&self) {}
     <|>type Output;
     const CONST: usize = 42;
-    fn foo(&self) { todo!() }
-    fn baz(&self) { todo!() }
+    fn foo(&self) {
+        todo!()
+    }
+    fn baz(&self) {
+        todo!()
+    }
 
-}",
+}"#,
         );
     }
 
@@ -226,7 +238,7 @@ impl Foo for S {
     fn test_copied_overriden_members() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo {
     fn foo(&self);
     fn bar(&self) -> bool { true }
@@ -238,8 +250,8 @@ struct S;
 impl Foo for S {
     fn bar(&self) {}
 <|>
-}",
-            "
+}"#,
+            r#"
 trait Foo {
     fn foo(&self);
     fn bar(&self) -> bool { true }
@@ -250,9 +262,11 @@ struct S;
 
 impl Foo for S {
     fn bar(&self) {}
-    <|>fn foo(&self) { todo!() }
+    <|>fn foo(&self) {
+        todo!()
+    }
 
-}",
+}"#,
         );
     }
 
@@ -260,16 +274,18 @@ impl Foo for S {
     fn test_empty_impl_def() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo { fn foo(&self); }
 struct S;
-impl Foo for S { <|> }",
-            "
+impl Foo for S { <|> }"#,
+            r#"
 trait Foo { fn foo(&self); }
 struct S;
 impl Foo for S {
-    <|>fn foo(&self) { todo!() }
-}",
+    <|>fn foo(&self) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -277,16 +293,18 @@ impl Foo for S {
     fn fill_in_type_params_1() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo<T> { fn foo(&self, t: T) -> &T; }
 struct S;
-impl Foo<u32> for S { <|> }",
-            "
+impl Foo<u32> for S { <|> }"#,
+            r#"
 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 {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -294,16 +312,18 @@ impl Foo<u32> for S {
     fn fill_in_type_params_2() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo<T> { fn foo(&self, t: T) -> &T; }
 struct S;
-impl<U> Foo<U> for S { <|> }",
-            "
+impl<U> Foo<U> for S { <|> }"#,
+            r#"
 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 {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -311,16 +331,18 @@ impl<U> Foo<U> for S {
     fn test_cursor_after_empty_impl_def() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo { fn foo(&self); }
 struct S;
-impl Foo for S {}<|>",
-            "
+impl Foo for S {}<|>"#,
+            r#"
 trait Foo { fn foo(&self); }
 struct S;
 impl Foo for S {
-    <|>fn foo(&self) { todo!() }
-}",
+    <|>fn foo(&self) {
+        todo!()
+    }
+}"#,
         )
     }
 
@@ -328,22 +350,24 @@ impl Foo for S {
     fn test_qualify_path_1() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     pub struct Bar;
     trait Foo { fn foo(&self, bar: Bar); }
 }
 struct S;
-impl foo::Foo for S { <|> }",
-            "
+impl foo::Foo for S { <|> }"#,
+            r#"
 mod foo {
     pub struct Bar;
     trait Foo { fn foo(&self, bar: Bar); }
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar) { todo!() }
-}",
+    <|>fn foo(&self, bar: foo::Bar) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -351,22 +375,24 @@ impl foo::Foo for S {
     fn test_qualify_path_generic() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     pub struct Bar<T>;
     trait Foo { fn foo(&self, bar: Bar<u32>); }
 }
 struct S;
-impl foo::Foo for S { <|> }",
-            "
+impl foo::Foo for S { <|> }"#,
+            r#"
 mod foo {
     pub struct Bar<T>;
     trait Foo { fn foo(&self, bar: Bar<u32>); }
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>) { todo!() }
-}",
+    <|>fn foo(&self, bar: foo::Bar<u32>) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -374,22 +400,24 @@ impl foo::Foo for S {
     fn test_qualify_path_and_substitute_param() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     pub struct Bar<T>;
     trait Foo<T> { fn foo(&self, bar: Bar<T>); }
 }
 struct S;
-impl foo::Foo<u32> for S { <|> }",
-            "
+impl foo::Foo<u32> for S { <|> }"#,
+            r#"
 mod foo {
     pub struct Bar<T>;
     trait Foo<T> { fn foo(&self, bar: Bar<T>); }
 }
 struct S;
 impl foo::Foo<u32> for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>) { todo!() }
-}",
+    <|>fn foo(&self, bar: foo::Bar<u32>) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -398,15 +426,15 @@ impl foo::Foo<u32> for S {
         // when substituting params, the substituted param should not be qualified!
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     trait Foo<T> { fn foo(&self, bar: T); }
     pub struct Param;
 }
 struct Param;
 struct S;
-impl foo::Foo<Param> for S { <|> }",
-            "
+impl foo::Foo<Param> for S { <|> }"#,
+            r#"
 mod foo {
     trait Foo<T> { fn foo(&self, bar: T); }
     pub struct Param;
@@ -414,8 +442,10 @@ mod foo {
 struct Param;
 struct S;
 impl foo::Foo<Param> for S {
-    <|>fn foo(&self, bar: Param) { todo!() }
-}",
+    <|>fn foo(&self, bar: Param) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -423,15 +453,15 @@ impl foo::Foo<Param> for S {
     fn test_qualify_path_associated_item() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     pub struct Bar<T>;
     impl Bar<T> { type Assoc = u32; }
     trait Foo { fn foo(&self, bar: Bar<u32>::Assoc); }
 }
 struct S;
-impl foo::Foo for S { <|> }",
-            "
+impl foo::Foo for S { <|> }"#,
+            r#"
 mod foo {
     pub struct Bar<T>;
     impl Bar<T> { type Assoc = u32; }
@@ -439,8 +469,10 @@ 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) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -448,15 +480,15 @@ impl foo::Foo for S {
     fn test_qualify_path_nested() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     pub struct Bar<T>;
     pub struct Baz;
     trait Foo { fn foo(&self, bar: Bar<Baz>); }
 }
 struct S;
-impl foo::Foo for S { <|> }",
-            "
+impl foo::Foo for S { <|> }"#,
+            r#"
 mod foo {
     pub struct Bar<T>;
     pub struct Baz;
@@ -464,8 +496,10 @@ 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>) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -473,22 +507,24 @@ impl foo::Foo for S {
     fn test_qualify_path_fn_trait_notation() {
         check_assist(
             add_missing_impl_members,
-            "
+            r#"
 mod foo {
     pub trait Fn<Args> { type Output; }
     trait Foo { fn foo(&self, bar: dyn Fn(u32) -> i32); }
 }
 struct S;
-impl foo::Foo for S { <|> }",
-            "
+impl foo::Foo for S { <|> }"#,
+            r#"
 mod foo {
     pub trait Fn<Args> { type Output; }
     trait Foo { fn foo(&self, bar: dyn Fn(u32) -> i32); }
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: dyn Fn(u32) -> i32) { todo!() }
-}",
+    <|>fn foo(&self, bar: dyn Fn(u32) -> i32) {
+        todo!()
+    }
+}"#,
         );
     }
 
@@ -496,10 +532,10 @@ impl foo::Foo for S {
     fn test_empty_trait() {
         check_assist_not_applicable(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo;
 struct S;
-impl Foo for S { <|> }",
+impl Foo for S { <|> }"#,
         )
     }
 
@@ -507,13 +543,13 @@ impl Foo for S { <|> }",
     fn test_ignore_unnamed_trait_members_and_default_methods() {
         check_assist_not_applicable(
             add_missing_impl_members,
-            "
+            r#"
 trait Foo {
     fn (arg: u32);
     fn valid(some: u32) -> bool { false }
 }
 struct S;
-impl Foo for S { <|> }",
+impl Foo for S { <|> }"#,
         )
     }
 
@@ -544,7 +580,9 @@ trait Foo {
 struct S;
 impl Foo for S {
     <|>type Output;
-    fn foo(&self) { todo!() }
+    fn foo(&self) {
+        todo!()
+    }
 }"#,
         )
     }
@@ -553,7 +591,7 @@ impl Foo for S {
     fn test_default_methods() {
         check_assist(
             add_missing_default_members,
-            "
+            r#"
 trait Foo {
     type Output;
 
@@ -563,8 +601,8 @@ trait Foo {
     fn foo(some: u32) -> bool;
 }
 struct S;
-impl Foo for S { <|> }",
-            "
+impl Foo for S { <|> }"#,
+            r#"
 trait Foo {
     type Output;
 
@@ -576,7 +614,7 @@ trait Foo {
 struct S;
 impl Foo for S {
     <|>fn valid(some: u32) -> bool { false }
-}",
+}"#,
         )
     }
 }
diff --git a/crates/ra_assists/src/handlers/early_return.rs b/crates/ra_assists/src/handlers/early_return.rs
index ea6c56f8c..eede2fe91 100644
--- a/crates/ra_assists/src/handlers/early_return.rs
+++ b/crates/ra_assists/src/handlers/early_return.rs
@@ -2,7 +2,7 @@ use std::{iter::once, ops::RangeInclusive};
 
 use ra_syntax::{
     algo::replace_children,
-    ast::{self, edit::IndentLevel, make, Block, Pat::TupleStructPat},
+    ast::{self, edit::IndentLevel, make},
     AstNode,
     SyntaxKind::{FN_DEF, LOOP_EXPR, L_CURLY, R_CURLY, WHILE_EXPR, WHITESPACE},
     SyntaxNode,
@@ -47,7 +47,7 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx) -> Option<Assist> {
     // Check if there is an IfLet that we can handle.
     let if_let_pat = match cond.pat() {
         None => None, // No IfLet, supported.
-        Some(TupleStructPat(pat)) if pat.args().count() == 1 => {
+        Some(ast::Pat::TupleStructPat(pat)) if pat.args().count() == 1 => {
             let path = pat.path()?;
             match path.qualifier() {
                 None => {
@@ -61,9 +61,9 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx) -> Option<Assist> {
     };
 
     let cond_expr = cond.expr()?;
-    let then_block = if_expr.then_branch()?.block()?;
+    let then_block = if_expr.then_branch()?;
 
-    let parent_block = if_expr.syntax().parent()?.ancestors().find_map(ast::Block::cast)?;
+    let parent_block = if_expr.syntax().parent()?.ancestors().find_map(ast::BlockExpr::cast)?;
 
     if parent_block.expr()? != if_expr.clone().into() {
         return None;
@@ -80,7 +80,7 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx) -> Option<Assist> {
         return None;
     }
 
-    let parent_container = parent_block.syntax().parent()?.parent()?;
+    let parent_container = parent_block.syntax().parent()?;
 
     let early_expression: ast::Expr = match parent_container.kind() {
         WHILE_EXPR | LOOP_EXPR => make::expr_continue(),
@@ -144,13 +144,13 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx) -> Option<Assist> {
             }
         };
         edit.target(if_expr.syntax().text_range());
-        edit.replace_ast(parent_block, ast::Block::cast(new_block).unwrap());
+        edit.replace_ast(parent_block, ast::BlockExpr::cast(new_block).unwrap());
         edit.set_cursor(cursor_position);
 
         fn replace(
             new_expr: &SyntaxNode,
-            then_block: &Block,
-            parent_block: &Block,
+            then_block: &ast::BlockExpr,
+            parent_block: &ast::BlockExpr,
             if_expr: &ast::IfExpr,
         ) -> SyntaxNode {
             let then_block_items = IndentLevel::from(1).decrease_indent(then_block.clone());
diff --git a/crates/ra_assists/src/handlers/inline_local_variable.rs b/crates/ra_assists/src/handlers/inline_local_variable.rs
index f5702f6e0..60ec536a7 100644
--- a/crates/ra_assists/src/handlers/inline_local_variable.rs
+++ b/crates/ra_assists/src/handlers/inline_local_variable.rs
@@ -89,6 +89,7 @@ pub(crate) fn inline_local_variable(ctx: AssistCtx) -> Option<Assist> {
             | (ast::Expr::ParenExpr(_), _)
             | (ast::Expr::PathExpr(_), _)
             | (ast::Expr::BlockExpr(_), _)
+            | (ast::Expr::EffectExpr(_), _)
             | (_, ast::Expr::CallExpr(_))
             | (_, ast::Expr::TupleExpr(_))
             | (_, ast::Expr::ArrayExpr(_))
diff --git a/crates/ra_assists/src/handlers/introduce_variable.rs b/crates/ra_assists/src/handlers/introduce_variable.rs
index eda9ac296..39c656305 100644
--- a/crates/ra_assists/src/handlers/introduce_variable.rs
+++ b/crates/ra_assists/src/handlers/introduce_variable.rs
@@ -111,7 +111,7 @@ fn valid_target_expr(node: SyntaxNode) -> Option<ast::Expr> {
 /// expression like a lambda or match arm.
 fn anchor_stmt(expr: ast::Expr) -> Option<(SyntaxNode, bool)> {
     expr.syntax().ancestors().find_map(|node| {
-        if let Some(expr) = node.parent().and_then(ast::Block::cast).and_then(|it| it.expr()) {
+        if let Some(expr) = node.parent().and_then(ast::BlockExpr::cast).and_then(|it| it.expr()) {
             if expr.syntax() == &node {
                 tested_by!(test_introduce_var_last_expr);
                 return Some((node, false));
diff --git a/crates/ra_assists/src/handlers/move_guard.rs b/crates/ra_assists/src/handlers/move_guard.rs
index d5ccdd91c..b084dd9ee 100644
--- a/crates/ra_assists/src/handlers/move_guard.rs
+++ b/crates/ra_assists/src/handlers/move_guard.rs
@@ -113,9 +113,9 @@ pub(crate) fn move_arm_cond_to_match_guard(ctx: AssistCtx) -> Option<Assist> {
         "Move condition to match guard",
         |edit| {
             edit.target(if_expr.syntax().text_range());
-            let then_only_expr = then_block.block().and_then(|it| it.statements().next()).is_none();
+            let then_only_expr = then_block.statements().next().is_none();
 
-            match &then_block.block().and_then(|it| it.expr()) {
+            match &then_block.expr() {
                 Some(then_expr) if then_only_expr => {
                     edit.replace(if_expr.syntax().text_range(), then_expr.syntax().text())
                 }
diff --git a/crates/ra_assists/src/handlers/replace_if_let_with_match.rs b/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
index 0a0a88f3d..9841f6980 100644
--- a/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
+++ b/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
@@ -1,11 +1,10 @@
 use ra_fmt::unwrap_trivial_block;
 use ra_syntax::{
-    ast::{self, make},
+    ast::{self, edit::IndentLevel, make},
     AstNode,
 };
 
-use crate::{Assist, AssistCtx, AssistId};
-use ast::edit::IndentLevel;
+use crate::{utils::TryEnum, Assist, AssistCtx, AssistId};
 
 // Assist: replace_if_let_with_match
 //
@@ -44,15 +43,21 @@ pub(crate) fn replace_if_let_with_match(ctx: AssistCtx) -> Option<Assist> {
         ast::ElseBranch::IfExpr(_) => return None,
     };
 
-    ctx.add_assist(AssistId("replace_if_let_with_match"), "Replace with match", |edit| {
+    let sema = ctx.sema;
+    ctx.add_assist(AssistId("replace_if_let_with_match"), "Replace with match", move |edit| {
         let match_expr = {
             let then_arm = {
                 let then_expr = unwrap_trivial_block(then_block);
-                make::match_arm(vec![pat], then_expr)
+                make::match_arm(vec![pat.clone()], then_expr)
             };
             let else_arm = {
+                let pattern = sema
+                    .type_of_pat(&pat)
+                    .and_then(|ty| TryEnum::from_ty(sema, &ty))
+                    .map(|it| it.sad_pattern())
+                    .unwrap_or_else(|| make::placeholder_pat().into());
                 let else_expr = unwrap_trivial_block(else_block);
-                make::match_arm(vec![make::placeholder_pat().into()], else_expr)
+                make::match_arm(vec![pattern], else_expr)
             };
             make::expr_match(expr, make::match_arm_list(vec![then_arm, else_arm]))
         };
@@ -68,6 +73,7 @@ pub(crate) fn replace_if_let_with_match(ctx: AssistCtx) -> Option<Assist> {
 #[cfg(test)]
 mod tests {
     use super::*;
+
     use crate::helpers::{check_assist, check_assist_target};
 
     #[test]
@@ -145,4 +151,64 @@ impl VariantData {
         }",
         );
     }
+
+    #[test]
+    fn special_case_option() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn foo(x: Option<i32>) {
+    <|>if let Some(x) = x {
+        println!("{}", x)
+    } else {
+        println!("none")
+    }
+}
+           "#,
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn foo(x: Option<i32>) {
+    <|>match x {
+        Some(x) => println!("{}", x),
+        None => println!("none"),
+    }
+}
+           "#,
+        );
+    }
+
+    #[test]
+    fn special_case_result() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+use Result::*;
+
+fn foo(x: Result<i32, ()>) {
+    <|>if let Ok(x) = x {
+        println!("{}", x)
+    } else {
+        println!("none")
+    }
+}
+           "#,
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+use Result::*;
+
+fn foo(x: Result<i32, ()>) {
+    <|>match x {
+        Ok(x) => println!("{}", x),
+        Err(_) => println!("none"),
+    }
+}
+           "#,
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/replace_let_with_if_let.rs b/crates/ra_assists/src/handlers/replace_let_with_if_let.rs
index bdbaae389..0cf23b754 100644
--- a/crates/ra_assists/src/handlers/replace_let_with_if_let.rs
+++ b/crates/ra_assists/src/handlers/replace_let_with_if_let.rs
@@ -1,6 +1,5 @@
 use std::iter::once;
 
-use hir::Adt;
 use ra_syntax::{
     ast::{
         self,
@@ -12,6 +11,7 @@ use ra_syntax::{
 
 use crate::{
     assist_ctx::{Assist, AssistCtx},
+    utils::TryEnum,
     AssistId,
 };
 
@@ -45,20 +45,10 @@ pub(crate) fn replace_let_with_if_let(ctx: AssistCtx) -> Option<Assist> {
     let init = let_stmt.initializer()?;
     let original_pat = let_stmt.pat()?;
     let ty = ctx.sema.type_of_expr(&init)?;
-    let enum_ = match ty.as_adt() {
-        Some(Adt::Enum(it)) => it,
-        _ => return None,
-    };
-    let happy_case =
-        [("Result", "Ok"), ("Option", "Some")].iter().find_map(|(known_type, happy_case)| {
-            if &enum_.name(ctx.db).to_string() == known_type {
-                return Some(happy_case);
-            }
-            None
-        });
+    let happy_variant = TryEnum::from_ty(ctx.sema, &ty).map(|it| it.happy_case());
 
     ctx.add_assist(AssistId("replace_let_with_if_let"), "Replace with if-let", |edit| {
-        let with_placeholder: ast::Pat = match happy_case {
+        let with_placeholder: ast::Pat = match happy_variant {
             None => make::placeholder_pat().into(),
             Some(var_name) => make::tuple_struct_pat(
                 make::path_unqualified(make::path_segment(make::name_ref(var_name))),
diff --git a/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs b/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
index 2f02df303..918e8dd8d 100644
--- a/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
@@ -27,7 +27,7 @@ pub(crate) fn replace_qualified_name_with_use(ctx: AssistCtx) -> Option<Assist>
         return None;
     }
 
-    let hir_path = hir::Path::from_ast(path.clone())?;
+    let hir_path = ctx.sema.lower_path(&path)?;
     let segments = collect_hir_path_segments(&hir_path)?;
     if segments.len() < 2 {
         return None;
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 62cb7a763..62d4ea522 100644
--- a/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
+++ b/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
@@ -1,12 +1,11 @@
 use std::iter;
 
 use ra_syntax::{
-    ast::{self, make},
+    ast::{self, edit::IndentLevel, make},
     AstNode,
 };
 
-use crate::{Assist, AssistCtx, AssistId};
-use ast::edit::IndentLevel;
+use crate::{utils::TryEnum, Assist, AssistCtx, AssistId};
 
 // Assist: replace_unwrap_with_match
 //
@@ -38,42 +37,27 @@ pub(crate) fn replace_unwrap_with_match(ctx: AssistCtx) -> Option<Assist> {
     }
     let caller = method_call.expr()?;
     let ty = ctx.sema.type_of_expr(&caller)?;
+    let happy_variant = TryEnum::from_ty(ctx.sema, &ty)?.happy_case();
 
-    let type_name = ty.as_adt()?.name(ctx.sema.db).to_string();
+    ctx.add_assist(AssistId("replace_unwrap_with_match"), "Replace unwrap with match", |edit| {
+        let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
+        let it = make::bind_pat(make::name("a")).into();
+        let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
 
-    for (unwrap_type, variant_name) in [("Result", "Ok"), ("Option", "Some")].iter() {
-        if &type_name == unwrap_type {
-            return ctx.add_assist(
-                AssistId("replace_unwrap_with_match"),
-                "Replace unwrap with match",
-                |edit| {
-                    let ok_path =
-                        make::path_unqualified(make::path_segment(make::name_ref(variant_name)));
-                    let it = make::bind_pat(make::name("a")).into();
-                    let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
+        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 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 err_arm = make::match_arm(iter::once(make::placeholder_pat().into()), unreachable_call);
 
-                    let unreachable_call = make::unreachable_macro_call().into();
-                    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]);
+        let match_expr = make::expr_match(caller.clone(), match_arm_list);
+        let match_expr = IndentLevel::from_node(method_call.syntax()).increase_indent(match_expr);
 
-                    let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
-                    let match_expr = make::expr_match(caller.clone(), match_arm_list);
-                    let match_expr =
-                        IndentLevel::from_node(method_call.syntax()).increase_indent(match_expr);
-
-                    edit.target(method_call.syntax().text_range());
-                    edit.set_cursor(caller.syntax().text_range().start());
-                    edit.replace_ast::<ast::Expr>(method_call.into(), match_expr);
-                },
-            );
-        }
-    }
-    None
+        edit.target(method_call.syntax().text_range());
+        edit.set_cursor(caller.syntax().text_range().start());
+        edit.replace_ast::<ast::Expr>(method_call.into(), match_expr);
+    })
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/unwrap_block.rs b/crates/ra_assists/src/handlers/unwrap_block.rs
new file mode 100644
index 000000000..58649c47e
--- /dev/null
+++ b/crates/ra_assists/src/handlers/unwrap_block.rs
@@ -0,0 +1,348 @@
+use crate::{Assist, AssistCtx, AssistId};
+
+use ast::{BlockExpr, Expr, ForExpr, IfExpr, LoopBodyOwner, LoopExpr, WhileExpr};
+use ra_fmt::unwrap_trivial_block;
+use ra_syntax::{ast, AstNode, TextRange, T};
+
+// Assist: unwrap_block
+//
+// This assist removes if...else, for, while and loop control statements to just keep the body.
+//
+// ```
+// fn foo() {
+//     if true {<|>
+//         println!("foo");
+//     }
+// }
+// ```
+// ->
+// ```
+// fn foo() {
+//     println!("foo");
+// }
+// ```
+pub(crate) fn unwrap_block(ctx: AssistCtx) -> Option<Assist> {
+    let l_curly_token = ctx.find_token_at_offset(T!['{'])?;
+
+    let res = if let Some(if_expr) = l_curly_token.ancestors().find_map(IfExpr::cast) {
+        // if expression
+        let expr_to_unwrap = if_expr.blocks().find_map(|expr| extract_expr(ctx.frange.range, expr));
+        let expr_to_unwrap = expr_to_unwrap?;
+        // Find if we are in a else if block
+        let ancestor = if_expr.syntax().ancestors().skip(1).find_map(ast::IfExpr::cast);
+
+        if let Some(ancestor) = ancestor {
+            Some((ast::Expr::IfExpr(ancestor), expr_to_unwrap))
+        } else {
+            Some((ast::Expr::IfExpr(if_expr), expr_to_unwrap))
+        }
+    } else if let Some(for_expr) = l_curly_token.ancestors().find_map(ForExpr::cast) {
+        // for expression
+        let block_expr = for_expr.loop_body()?;
+        extract_expr(ctx.frange.range, block_expr)
+            .map(|expr_to_unwrap| (ast::Expr::ForExpr(for_expr), expr_to_unwrap))
+    } else if let Some(while_expr) = l_curly_token.ancestors().find_map(WhileExpr::cast) {
+        // while expression
+        let block_expr = while_expr.loop_body()?;
+        extract_expr(ctx.frange.range, block_expr)
+            .map(|expr_to_unwrap| (ast::Expr::WhileExpr(while_expr), expr_to_unwrap))
+    } else if let Some(loop_expr) = l_curly_token.ancestors().find_map(LoopExpr::cast) {
+        // loop expression
+        let block_expr = loop_expr.loop_body()?;
+        extract_expr(ctx.frange.range, block_expr)
+            .map(|expr_to_unwrap| (ast::Expr::LoopExpr(loop_expr), expr_to_unwrap))
+    } else {
+        None
+    };
+
+    let (expr, expr_to_unwrap) = res?;
+    ctx.add_assist(AssistId("unwrap_block"), "Unwrap block", |edit| {
+        edit.set_cursor(expr.syntax().text_range().start());
+        edit.target(expr_to_unwrap.syntax().text_range());
+
+        let pat_start: &[_] = &[' ', '{', '\n'];
+        let expr_to_unwrap = expr_to_unwrap.to_string();
+        let expr_string = expr_to_unwrap.trim_start_matches(pat_start);
+        let mut expr_string_lines: Vec<&str> = expr_string.lines().collect();
+        expr_string_lines.pop(); // Delete last line
+
+        let expr_string = expr_string_lines
+            .into_iter()
+            .map(|line| line.replacen("    ", "", 1)) // Delete indentation
+            .collect::<Vec<String>>()
+            .join("\n");
+
+        edit.replace(expr.syntax().text_range(), expr_string);
+    })
+}
+
+fn extract_expr(cursor_range: TextRange, block: BlockExpr) -> Option<Expr> {
+    let cursor_in_range = block.l_curly_token()?.text_range().contains_range(cursor_range);
+
+    if cursor_in_range {
+        Some(unwrap_trivial_block(block))
+    } else {
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::helpers::{check_assist, check_assist_not_applicable};
+
+    use super::*;
+
+    #[test]
+    fn simple_if() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                bar();
+                if true {<|>
+                    foo();
+
+                    //comment
+                    bar();
+                } else {
+                    println!("bar");
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                bar();
+                <|>foo();
+
+                //comment
+                bar();
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_if_else() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                bar();
+                if true {
+                    foo();
+
+                    //comment
+                    bar();
+                } else {<|>
+                    println!("bar");
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                bar();
+                <|>println!("bar");
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_if_else_if() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                //bar();
+                if true {
+                    println!("true");
+
+                    //comment
+                    //bar();
+                } else if false {<|>
+                    println!("bar");
+                } else {
+                    println!("foo");
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                //bar();
+                <|>println!("bar");
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_if_bad_cursor_position() {
+        check_assist_not_applicable(
+            unwrap_block,
+            r#"
+            fn main() {
+                bar();<|>
+                if true {
+                    foo();
+
+                    //comment
+                    bar();
+                } else {
+                    println!("bar");
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_for() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                for i in 0..5 {<|>
+                    if true {
+                        foo();
+
+                        //comment
+                        bar();
+                    } else {
+                        println!("bar");
+                    }
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                <|>if true {
+                    foo();
+
+                    //comment
+                    bar();
+                } else {
+                    println!("bar");
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_if_in_for() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                for i in 0..5 {
+                    if true {<|>
+                        foo();
+
+                        //comment
+                        bar();
+                    } else {
+                        println!("bar");
+                    }
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                for i in 0..5 {
+                    <|>foo();
+
+                    //comment
+                    bar();
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_loop() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                loop {<|>
+                    if true {
+                        foo();
+
+                        //comment
+                        bar();
+                    } else {
+                        println!("bar");
+                    }
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                <|>if true {
+                    foo();
+
+                    //comment
+                    bar();
+                } else {
+                    println!("bar");
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_while() {
+        check_assist(
+            unwrap_block,
+            r#"
+            fn main() {
+                while true {<|>
+                    if true {
+                        foo();
+
+                        //comment
+                        bar();
+                    } else {
+                        println!("bar");
+                    }
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                <|>if true {
+                    foo();
+
+                    //comment
+                    bar();
+                } else {
+                    println!("bar");
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn simple_if_in_while_bad_cursor_position() {
+        check_assist_not_applicable(
+            unwrap_block,
+            r#"
+            fn main() {
+                while true {
+                    if true {
+                        foo();<|>
+
+                        //comment
+                        bar();
+                    } else {
+                        println!("bar");
+                    }
+                }
+            }
+            "#,
+        );
+    }
+}