13 files changed, 155 insertions, 40 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 9ddbeac47..1aa0c072d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -349,6 +349,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
 
 [[package]]
+name = "dissimilar"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc4b29f4b9bb94bf267d57269fd0706d343a160937108e9619fe380645428abb"
+
+[[package]]
 name = "drop_bomb"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1343,6 +1349,7 @@ dependencies = [
  "anyhow",
  "cfg",
  "crossbeam-channel 0.5.0",
+ "dissimilar",
  "env_logger",
  "expect-test",
  "flycheck",
diff --git a/crates/completion/src/completions/attribute.rs b/crates/completion/src/completions/attribute.rs
index 19ce2482f..8695eed39 100644
--- a/crates/completion/src/completions/attribute.rs
+++ b/crates/completion/src/completions/attribute.rs
@@ -234,7 +234,7 @@ fn parse_comma_sep_input(derive_input: ast::TokenTree) -> Result<FxHashSet<Strin
                         current_derive = String::new();
                     }
                 } else {
-                    current_derive.push_str(token.to_string().trim());
+                    current_derive.push_str(token.text().trim());
                 }
             }
 
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index 9bf358775..5682e122d 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -454,7 +454,7 @@ mod diagnostics {
                                     });
                                 for token in tokens {
                                     if token.kind() == SyntaxKind::IDENT
-                                        && token.to_string() == *name
+                                        && token.text() == name.as_str()
                                     {
                                         precise_location = Some(token.text_range());
                                         break 'outer;
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index 6382521fb..80b60d59f 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -259,7 +259,8 @@ fn format_args_expand(
     }
     for arg in &mut args {
         // Remove `key =`.
-        if matches!(arg.get(1), Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p))) if p.char == '=') {
+        if matches!(arg.get(1), Some(tt::TokenTree::Leaf(tt::Leaf::Punct(p))) if p.char == '=' && p.spacing != tt::Spacing::Joint)
+        {
             arg.drain(..2);
         }
     }
diff --git a/crates/proc_macro_srv/src/rustc_server.rs b/crates/proc_macro_srv/src/rustc_server.rs
index 503f4c101..b54aa1f3b 100644
--- a/crates/proc_macro_srv/src/rustc_server.rs
+++ b/crates/proc_macro_srv/src/rustc_server.rs
@@ -204,17 +204,18 @@ pub mod token_stream {
                 let content = subtree
                     .token_trees
                     .iter()
-                    .map(|tkn| {
-                        let s = to_text(tkn);
+                    .fold((String::new(), true), |(last, last_to_joint), tkn| {
+                        let s = [last, to_text(tkn)].join(if last_to_joint { "" } else { " " });
+                        let mut is_joint = false;
                         if let tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) = tkn {
-                            if punct.spacing == tt::Spacing::Alone {
-                                return s + " ";
+                            if punct.spacing == tt::Spacing::Joint {
+                                is_joint = true;
                             }
                         }
-                        s
+                        (s, is_joint)
                     })
-                    .collect::<Vec<_>>()
-                    .concat();
+                    .0;
+
                 let (open, close) = match subtree.delimiter.map(|it| it.kind) {
                     None => ("", ""),
                     Some(tt::DelimiterKind::Brace) => ("{", "}"),
@@ -710,4 +711,32 @@ mod tests {
         assert_eq!(srv.character('c').text, "'c'");
         assert_eq!(srv.byte_string(b"1234586\x88").text, "b\"1234586\\x88\"");
     }
+
+    #[test]
+    fn test_rustc_server_to_string() {
+        let s = TokenStream {
+            subtree: tt::Subtree {
+                delimiter: None,
+                token_trees: vec![
+                    tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                        text: "struct".into(),
+                        id: tt::TokenId::unspecified(),
+                    })),
+                    tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                        text: "T".into(),
+                        id: tt::TokenId::unspecified(),
+                    })),
+                    tt::TokenTree::Subtree(tt::Subtree {
+                        delimiter: Some(tt::Delimiter {
+                            id: tt::TokenId::unspecified(),
+                            kind: tt::DelimiterKind::Brace,
+                        }),
+                        token_trees: vec![],
+                    }),
+                ],
+            },
+        };
+
+        assert_eq!(s.to_string(), "struct T {}");
+    }
 }
diff --git a/crates/project_model/src/cargo_workspace.rs b/crates/project_model/src/cargo_workspace.rs
index bb3b6f2ef..1700cb8a7 100644
--- a/crates/project_model/src/cargo_workspace.rs
+++ b/crates/project_model/src/cargo_workspace.rs
@@ -1,6 +1,7 @@
 //! FIXME: write short doc here
 
 use std::{
+    convert::TryInto,
     ffi::OsStr,
     ops,
     path::{Path, PathBuf},
@@ -196,8 +197,23 @@ impl CargoWorkspace {
         if let Some(target) = target {
             meta.other_options(vec![String::from("--filter-platform"), target]);
         }
+
         let mut meta = meta.exec().with_context(|| {
-            format!("Failed to run `cargo metadata --manifest-path {}`", cargo_toml.display())
+            let cwd: Option<AbsPathBuf> =
+                std::env::current_dir().ok().and_then(|p| p.try_into().ok());
+
+            let workdir = cargo_toml
+                .parent()
+                .map(|p| p.to_path_buf())
+                .or(cwd)
+                .map(|dir| dir.to_string_lossy().to_string())
+                .unwrap_or_else(|| "<failed to get path>".into());
+
+            format!(
+                "Failed to run `cargo metadata --manifest-path {}` in `{}`",
+                cargo_toml.display(),
+                workdir
+            )
         })?;
 
         let mut out_dir_by_id = FxHashMap::default();
@@ -334,6 +350,11 @@ pub(crate) fn load_extern_resources(
     let mut cmd = Command::new(toolchain::cargo());
     cmd.args(&["check", "--message-format=json", "--manifest-path"]).arg(cargo_toml);
 
+    // --all-targets includes tests, benches and examples in addition to the
+    // default lib and bins. This is an independent concept from the --targets
+    // flag below.
+    cmd.arg("--all-targets");
+
     if let Some(target) = &cargo_features.target {
         cmd.args(&["--target", target]);
     }
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 0a002337b..0a63593fb 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -17,6 +17,7 @@ path = "src/bin/main.rs"
 [dependencies]
 anyhow = "1.0.26"
 crossbeam-channel = "0.5.0"
+dissimilar = "1.0.2"
 env_logger = { version = "0.8.1", default-features = false }
 itertools = "0.10.0"
 jod-thread = "0.1.0"
diff --git a/crates/rust-analyzer/src/diff.rs b/crates/rust-analyzer/src/diff.rs
new file mode 100644
index 000000000..231be5807
--- /dev/null
+++ b/crates/rust-analyzer/src/diff.rs
@@ -0,0 +1,53 @@
+//! Generate minimal `TextEdit`s from different text versions
+use dissimilar::Chunk;
+use ide::{TextEdit, TextRange, TextSize};
+
+pub(crate) fn diff(left: &str, right: &str) -> TextEdit {
+    let chunks = dissimilar::diff(left, right);
+    textedit_from_chunks(chunks)
+}
+
+fn textedit_from_chunks(chunks: Vec<dissimilar::Chunk>) -> TextEdit {
+    let mut builder = TextEdit::builder();
+    let mut pos = TextSize::default();
+
+    let mut chunks = chunks.into_iter().peekable();
+    while let Some(chunk) = chunks.next() {
+        if let (Chunk::Delete(deleted), Some(&Chunk::Insert(inserted))) = (chunk, chunks.peek()) {
+            chunks.next().unwrap();
+            let deleted_len = TextSize::of(deleted);
+            builder.replace(TextRange::at(pos, deleted_len), inserted.into());
+            pos += deleted_len;
+            continue;
+        }
+
+        match chunk {
+            Chunk::Equal(text) => {
+                pos += TextSize::of(text);
+            }
+            Chunk::Delete(deleted) => {
+                let deleted_len = TextSize::of(deleted);
+                builder.delete(TextRange::at(pos, deleted_len));
+                pos += deleted_len;
+            }
+            Chunk::Insert(inserted) => {
+                builder.insert(pos, inserted.into());
+            }
+        }
+    }
+    builder.finish()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn diff_applies() {
+        let mut original = String::from("fn foo(a:u32){\n}");
+        let result = "fn foo(a: u32) {}";
+        let edit = diff(&original, result);
+        edit.apply(&mut original);
+        assert_eq!(original, result);
+    }
+}
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 23f323f55..948cfc17c 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -31,6 +31,7 @@ use serde_json::to_value;
 use stdx::{format_to, split_once};
 use syntax::{algo, ast, AstNode, TextRange, TextSize};
 
+use crate::diff::diff;
 use crate::{
     cargo_target_spec::CargoTargetSpec,
     config::RustfmtConfig,
@@ -840,7 +841,7 @@ pub(crate) fn handle_formatting(
     let crate_ids = snap.analysis.crate_for(file_id)?;
 
     let file_line_index = snap.analysis.file_line_index(file_id)?;
-    let end_position = to_proto::position(&file_line_index, TextSize::of(file.as_str()));
+    let file_line_endings = snap.file_line_endings(file_id);
 
     let mut rustfmt = match &snap.config.rustfmt {
         RustfmtConfig::Rustfmt { extra_args } => {
@@ -861,16 +862,18 @@ pub(crate) fn handle_formatting(
         }
     };
 
-    let mut rustfmt = rustfmt.stdin(Stdio::piped()).stdout(Stdio::piped()).spawn()?;
+    let mut rustfmt =
+        rustfmt.stdin(Stdio::piped()).stdout(Stdio::piped()).stderr(Stdio::piped()).spawn()?;
 
     rustfmt.stdin.as_mut().unwrap().write_all(file.as_bytes())?;
 
     let output = rustfmt.wait_with_output()?;
     let captured_stdout = String::from_utf8(output.stdout)?;
+    let captured_stderr = String::from_utf8(output.stderr).unwrap_or_default();
 
     if !output.status.success() {
         match output.status.code() {
-            Some(1) => {
+            Some(1) if !captured_stderr.contains("not installed") => {
                 // While `rustfmt` doesn't have a specific exit code for parse errors this is the
                 // likely cause exiting with 1. Most Language Servers swallow parse errors on
                 // formatting because otherwise an error is surfaced to the user on top of the
@@ -886,8 +889,9 @@ pub(crate) fn handle_formatting(
                     format!(
                         r#"rustfmt exited with:
                            Status: {}
-                           stdout: {}"#,
-                        output.status, captured_stdout,
+                           stdout: {}
+                           stderr: {}"#,
+                        output.status, captured_stdout, captured_stderr,
                     ),
                 )
                 .into());
@@ -899,10 +903,11 @@ pub(crate) fn handle_formatting(
         // The document is already formatted correctly -- no edits needed.
         Ok(None)
     } else {
-        Ok(Some(vec![lsp_types::TextEdit {
-            range: Range::new(Position::new(0, 0), end_position),
-            new_text: captured_stdout,
-        }]))
+        Ok(Some(to_proto::text_edit_vec(
+            &file_line_index,
+            file_line_endings,
+            diff(&file, &captured_stdout),
+        )))
     }
 }
 
diff --git a/crates/rust-analyzer/src/lib.rs b/crates/rust-analyzer/src/lib.rs
index d538ad69a..c9494e300 100644
--- a/crates/rust-analyzer/src/lib.rs
+++ b/crates/rust-analyzer/src/lib.rs
@@ -34,6 +34,7 @@ mod request_metrics;
 mod lsp_utils;
 mod thread_pool;
 mod document;
+mod diff;
 pub mod lsp_ext;
 pub mod config;
 
diff --git a/crates/rust-analyzer/tests/rust-analyzer/main.rs b/crates/rust-analyzer/tests/rust-analyzer/main.rs
index e51eb2626..84db0856d 100644
--- a/crates/rust-analyzer/tests/rust-analyzer/main.rs
+++ b/crates/rust-analyzer/tests/rust-analyzer/main.rs
@@ -190,15 +190,10 @@ pub use std::collections::HashMap;
         },
         json!([
             {
-                "newText": r#"mod bar;
-
-fn main() {}
-
-pub use std::collections::HashMap;
-"#,
+                "newText": "",
                 "range": {
-                    "end": { "character": 0, "line": 6 },
-                    "start": { "character": 0, "line": 0 }
+                    "end": { "character": 0, "line": 3 },
+                    "start": { "character": 11, "line": 2 }
                 }
             }
         ]),
@@ -248,17 +243,17 @@ pub use std::collections::HashMap;
         },
         json!([
             {
-                "newText": r#"mod bar;
-
-async fn test() {}
-
-fn main() {}
-
-pub use std::collections::HashMap;
-"#,
+                "newText": "",
+                "range": {
+                    "end": { "character": 0, "line": 3 },
+                    "start": { "character": 17, "line": 2 }
+                }
+            },
+            {
+                "newText": "",
                 "range": {
-                    "end": { "character": 0, "line": 9 },
-                    "start": { "character": 0, "line": 0 }
+                    "end": { "character": 0, "line": 6 },
+                    "start": { "character": 11, "line": 5 }
                 }
             }
         ]),
diff --git a/crates/ssr/src/matching.rs b/crates/ssr/src/matching.rs
index 99b187311..6cf831431 100644
--- a/crates/ssr/src/matching.rs
+++ b/crates/ssr/src/matching.rs
@@ -473,7 +473,9 @@ impl<'db, 'sema> Matcher<'db, 'sema> {
                         }
                         SyntaxElement::Node(n) => {
                             if let Some(first_token) = n.first_token() {
-                                if Some(first_token.to_string()) == next_pattern_token {
+                                if Some(first_token.text().as_str())
+                                    == next_pattern_token.as_deref()
+                                {
                                     if let Some(SyntaxElement::Node(p)) = pattern.next() {
                                         // We have a subtree that starts with the next token in our pattern.
                                         self.attempt_match_token_tree(phase, &p, &n)?;
diff --git a/xtask/tests/tidy.rs b/xtask/tests/tidy.rs
index 6bfa922e6..d1ffb70ad 100644
--- a/xtask/tests/tidy.rs
+++ b/xtask/tests/tidy.rs
@@ -139,7 +139,7 @@ fn deny_clippy(path: &PathBuf, text: &String) {
         return;
     }
 
-    if text.contains("[\u{61}llow(clippy") {
+    if text.contains("\u{61}llow(clippy") {
         panic!(
             "\n\nallowing lints is forbidden: {}.
 rust-analyzer intentionally doesn't check clippy on CI.