397 files changed, 36615 insertions, 27931 deletions

diff --git a/crates/expect/Cargo.toml b/crates/expect/Cargo.toml
new file mode 100644
index 000000000..77775630d
--- /dev/null
+++ b/crates/expect/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "expect"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
+
+[dependencies]
+once_cell = "1"
+difference = "2"
+stdx = { path = "../stdx" }
diff --git a/crates/expect/src/lib.rs b/crates/expect/src/lib.rs
new file mode 100644
index 000000000..21a458d47
--- /dev/null
+++ b/crates/expect/src/lib.rs
@@ -0,0 +1,356 @@
+//! Snapshot testing library, see
+//! https://github.com/rust-analyzer/rust-analyzer/pull/5101
+use std::{
+    collections::HashMap,
+    env, fmt, fs, mem,
+    ops::Range,
+    panic,
+    path::{Path, PathBuf},
+    sync::Mutex,
+};
+
+use difference::Changeset;
+use once_cell::sync::Lazy;
+use stdx::{lines_with_ends, trim_indent};
+
+const HELP: &str = "
+You can update all `expect![[]]` tests by running:
+
+    env UPDATE_EXPECT=1 cargo test
+
+To update a single test, place the cursor on `expect` token and use `run` feature of rust-analyzer.
+";
+
+fn update_expect() -> bool {
+    env::var("UPDATE_EXPECT").is_ok()
+}
+
+/// expect![[r#"inline snapshot"#]]
+#[macro_export]
+macro_rules! expect {
+    [[$data:literal]] => {$crate::Expect {
+        position: $crate::Position {
+            file: file!(),
+            line: line!(),
+            column: column!(),
+        },
+        data: $data,
+    }};
+    [[]] => { $crate::expect![[""]] };
+}
+
+/// expect_file!["/crates/foo/test_data/bar.html"]
+#[macro_export]
+macro_rules! expect_file {
+    [$path:expr] => {$crate::ExpectFile {
+        path: std::path::PathBuf::from($path)
+    }};
+}
+
+#[derive(Debug)]
+pub struct Expect {
+    pub position: Position,
+    pub data: &'static str,
+}
+
+#[derive(Debug)]
+pub struct ExpectFile {
+    pub path: PathBuf,
+}
+
+#[derive(Debug)]
+pub struct Position {
+    pub file: &'static str,
+    pub line: u32,
+    pub column: u32,
+}
+
+impl fmt::Display for Position {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}:{}:{}", self.file, self.line, self.column)
+    }
+}
+
+impl Expect {
+    pub fn assert_eq(&self, actual: &str) {
+        let trimmed = self.trimmed();
+        if &trimmed == actual {
+            return;
+        }
+        Runtime::fail_expect(self, &trimmed, actual);
+    }
+    pub fn assert_debug_eq(&self, actual: &impl fmt::Debug) {
+        let actual = format!("{:#?}\n", actual);
+        self.assert_eq(&actual)
+    }
+
+    fn trimmed(&self) -> String {
+        if !self.data.contains('\n') {
+            return self.data.to_string();
+        }
+        trim_indent(self.data)
+    }
+
+    fn locate(&self, file: &str) -> Location {
+        let mut target_line = None;
+        let mut line_start = 0;
+        for (i, line) in lines_with_ends(file).enumerate() {
+            if i == self.position.line as usize - 1 {
+                let pat = "expect![[";
+                let offset = line.find(pat).unwrap();
+                let literal_start = line_start + offset + pat.len();
+                let indent = line.chars().take_while(|&it| it == ' ').count();
+                target_line = Some((literal_start, indent));
+                break;
+            }
+            line_start += line.len();
+        }
+        let (literal_start, line_indent) = target_line.unwrap();
+        let literal_length =
+            file[literal_start..].find("]]").expect("Couldn't find matching `]]` for `expect![[`.");
+        let literal_range = literal_start..literal_start + literal_length;
+        Location { line_indent, literal_range }
+    }
+}
+
+impl ExpectFile {
+    pub fn assert_eq(&self, actual: &str) {
+        let expected = self.read();
+        if actual == expected {
+            return;
+        }
+        Runtime::fail_file(self, &expected, actual);
+    }
+    pub fn assert_debug_eq(&self, actual: &impl fmt::Debug) {
+        let actual = format!("{:#?}\n", actual);
+        self.assert_eq(&actual)
+    }
+    fn read(&self) -> String {
+        fs::read_to_string(self.abs_path()).unwrap_or_default().replace("\r\n", "\n")
+    }
+    fn write(&self, contents: &str) {
+        fs::write(self.abs_path(), contents).unwrap()
+    }
+    fn abs_path(&self) -> PathBuf {
+        WORKSPACE_ROOT.join(&self.path)
+    }
+}
+
+#[derive(Default)]
+struct Runtime {
+    help_printed: bool,
+    per_file: HashMap<&'static str, FileRuntime>,
+}
+static RT: Lazy<Mutex<Runtime>> = Lazy::new(Default::default);
+
+impl Runtime {
+    fn fail_expect(expect: &Expect, expected: &str, actual: &str) {
+        let mut rt = RT.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        if update_expect() {
+            println!("\x1b[1m\x1b[92mupdating\x1b[0m: {}", expect.position);
+            rt.per_file
+                .entry(expect.position.file)
+                .or_insert_with(|| FileRuntime::new(expect))
+                .update(expect, actual);
+            return;
+        }
+        rt.panic(expect.position.to_string(), expected, actual);
+    }
+
+    fn fail_file(expect: &ExpectFile, expected: &str, actual: &str) {
+        let mut rt = RT.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        if update_expect() {
+            println!("\x1b[1m\x1b[92mupdating\x1b[0m: {}", expect.path.display());
+            expect.write(actual);
+            return;
+        }
+        rt.panic(expect.path.display().to_string(), expected, actual);
+    }
+
+    fn panic(&mut self, position: String, expected: &str, actual: &str) {
+        let print_help = !mem::replace(&mut self.help_printed, true);
+        let help = if print_help { HELP } else { "" };
+
+        let diff = Changeset::new(actual, expected, "\n");
+
+        println!(
+            "\n
+\x1b[1m\x1b[91merror\x1b[97m: expect test failed\x1b[0m
+   \x1b[1m\x1b[34m-->\x1b[0m {}
+{}
+\x1b[1mExpect\x1b[0m:
+----
+{}
+----
+
+\x1b[1mActual\x1b[0m:
+----
+{}
+----
+
+\x1b[1mDiff\x1b[0m:
+----
+{}
+----
+",
+            position, help, expected, actual, diff
+        );
+        // Use resume_unwind instead of panic!() to prevent a backtrace, which is unnecessary noise.
+        panic::resume_unwind(Box::new(()));
+    }
+}
+
+struct FileRuntime {
+    path: PathBuf,
+    original_text: String,
+    patchwork: Patchwork,
+}
+
+impl FileRuntime {
+    fn new(expect: &Expect) -> FileRuntime {
+        let path = WORKSPACE_ROOT.join(expect.position.file);
+        let original_text = fs::read_to_string(&path).unwrap();
+        let patchwork = Patchwork::new(original_text.clone());
+        FileRuntime { path, original_text, patchwork }
+    }
+    fn update(&mut self, expect: &Expect, actual: &str) {
+        let loc = expect.locate(&self.original_text);
+        let patch = format_patch(loc.line_indent.clone(), actual);
+        self.patchwork.patch(loc.literal_range, &patch);
+        fs::write(&self.path, &self.patchwork.text).unwrap()
+    }
+}
+
+#[derive(Debug)]
+struct Location {
+    line_indent: usize,
+    literal_range: Range<usize>,
+}
+
+#[derive(Debug)]
+struct Patchwork {
+    text: String,
+    indels: Vec<(Range<usize>, usize)>,
+}
+
+impl Patchwork {
+    fn new(text: String) -> Patchwork {
+        Patchwork { text, indels: Vec::new() }
+    }
+    fn patch(&mut self, mut range: Range<usize>, patch: &str) {
+        self.indels.push((range.clone(), patch.len()));
+        self.indels.sort_by_key(|(delete, _insert)| delete.start);
+
+        let (delete, insert) = self
+            .indels
+            .iter()
+            .take_while(|(delete, _)| delete.start < range.start)
+            .map(|(delete, insert)| (delete.end - delete.start, insert))
+            .fold((0usize, 0usize), |(x1, y1), (x2, y2)| (x1 + x2, y1 + y2));
+
+        for pos in &mut [&mut range.start, &mut range.end] {
+            **pos -= delete;
+            **pos += insert;
+        }
+
+        self.text.replace_range(range, &patch);
+    }
+}
+
+fn format_patch(line_indent: usize, patch: &str) -> String {
+    let mut max_hashes = 0;
+    let mut cur_hashes = 0;
+    for byte in patch.bytes() {
+        if byte != b'#' {
+            cur_hashes = 0;
+            continue;
+        }
+        cur_hashes += 1;
+        max_hashes = max_hashes.max(cur_hashes);
+    }
+    let hashes = &"#".repeat(max_hashes + 1);
+    let indent = &" ".repeat(line_indent);
+    let is_multiline = patch.contains('\n');
+
+    let mut buf = String::new();
+    buf.push('r');
+    buf.push_str(hashes);
+    buf.push('"');
+    if is_multiline {
+        buf.push('\n');
+    }
+    let mut final_newline = false;
+    for line in lines_with_ends(patch) {
+        if is_multiline && !line.trim().is_empty() {
+            buf.push_str(indent);
+            buf.push_str("    ");
+        }
+        buf.push_str(line);
+        final_newline = line.ends_with('\n');
+    }
+    if final_newline {
+        buf.push_str(indent);
+    }
+    buf.push('"');
+    buf.push_str(hashes);
+    buf
+}
+
+static WORKSPACE_ROOT: Lazy<PathBuf> = Lazy::new(|| {
+    let my_manifest =
+        env::var("CARGO_MANIFEST_DIR").unwrap_or_else(|_| env!("CARGO_MANIFEST_DIR").to_owned());
+    // Heuristic, see https://github.com/rust-lang/cargo/issues/3946
+    Path::new(&my_manifest)
+        .ancestors()
+        .filter(|it| it.join("Cargo.toml").exists())
+        .last()
+        .unwrap()
+        .to_path_buf()
+});
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_format_patch() {
+        let patch = format_patch(0, "hello\nworld\n");
+        expect![[r##"
+            r#"
+                hello
+                world
+            "#"##]]
+        .assert_eq(&patch);
+
+        let patch = format_patch(4, "single line");
+        expect![[r##"r#"single line"#"##]].assert_eq(&patch);
+    }
+
+    #[test]
+    fn test_patchwork() {
+        let mut patchwork = Patchwork::new("one two three".to_string());
+        patchwork.patch(4..7, "zwei");
+        patchwork.patch(0..3, "один");
+        patchwork.patch(8..13, "3");
+        expect![[r#"
+            Patchwork {
+                text: "один zwei 3",
+                indels: [
+                    (
+                        0..3,
+                        8,
+                    ),
+                    (
+                        4..7,
+                        4,
+                    ),
+                    (
+                        8..13,
+                        1,
+                    ),
+                ],
+            }
+        "#]]
+        .assert_debug_eq(&patchwork);
+    }
+}
diff --git a/crates/ra_flycheck/Cargo.toml b/crates/flycheck/Cargo.toml
index 1aa39bade..bea485694 100644
--- a/crates/ra_flycheck/Cargo.toml
+++ b/crates/flycheck/Cargo.toml
@@ -1,8 +1,9 @@
 [package]
 edition = "2018"
-name = "ra_flycheck"
+name = "flycheck"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/flycheck/src/lib.rs b/crates/flycheck/src/lib.rs
new file mode 100644
index 000000000..6804d9bda
--- /dev/null
+++ b/crates/flycheck/src/lib.rs
@@ -0,0 +1,317 @@
+//! cargo_check provides the functionality needed to run `cargo check` or
+//! another compatible command (f.x. clippy) in a background thread and provide
+//! LSP diagnostics based on the output of the command.
+
+use std::{
+    fmt,
+    io::{self, BufReader},
+    ops,
+    path::PathBuf,
+    process::{self, Command, Stdio},
+    time::Duration,
+};
+
+use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
+
+pub use cargo_metadata::diagnostic::{
+    Applicability, Diagnostic, DiagnosticCode, DiagnosticLevel, DiagnosticSpan,
+    DiagnosticSpanMacroExpansion,
+};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum FlycheckConfig {
+    CargoCommand {
+        command: String,
+        all_targets: bool,
+        all_features: bool,
+        features: Vec<String>,
+        extra_args: Vec<String>,
+    },
+    CustomCommand {
+        command: String,
+        args: Vec<String>,
+    },
+}
+
+impl fmt::Display for FlycheckConfig {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            FlycheckConfig::CargoCommand { command, .. } => write!(f, "cargo {}", command),
+            FlycheckConfig::CustomCommand { command, args } => {
+                write!(f, "{} {}", command, args.join(" "))
+            }
+        }
+    }
+}
+
+/// Flycheck wraps the shared state and communication machinery used for
+/// running `cargo check` (or other compatible command) and providing
+/// diagnostics based on the output.
+/// The spawned thread is shut down when this struct is dropped.
+#[derive(Debug)]
+pub struct FlycheckHandle {
+    // XXX: drop order is significant
+    sender: Sender<Restart>,
+    thread: jod_thread::JoinHandle,
+}
+
+impl FlycheckHandle {
+    pub fn spawn(
+        sender: Box<dyn Fn(Message) + Send>,
+        config: FlycheckConfig,
+        workspace_root: PathBuf,
+    ) -> FlycheckHandle {
+        let actor = FlycheckActor::new(sender, config, workspace_root);
+        let (sender, receiver) = unbounded::<Restart>();
+        let thread = jod_thread::spawn(move || actor.run(receiver));
+        FlycheckHandle { sender, thread }
+    }
+
+    /// Schedule a re-start of the cargo check worker.
+    pub fn update(&self) {
+        self.sender.send(Restart).unwrap();
+    }
+}
+
+#[derive(Debug)]
+pub enum Message {
+    /// Request adding a diagnostic with fixes included to a file
+    AddDiagnostic { workspace_root: PathBuf, diagnostic: Diagnostic },
+
+    /// Request check progress notification to client
+    Progress(Progress),
+}
+
+#[derive(Debug)]
+pub enum Progress {
+    DidStart,
+    DidCheckCrate(String),
+    DidFinish(io::Result<()>),
+    DidCancel,
+}
+
+struct Restart;
+
+struct FlycheckActor {
+    sender: Box<dyn Fn(Message) + Send>,
+    config: FlycheckConfig,
+    workspace_root: PathBuf,
+    /// WatchThread exists to wrap around the communication needed to be able to
+    /// run `cargo check` without blocking. Currently the Rust standard library
+    /// doesn't provide a way to read sub-process output without blocking, so we
+    /// have to wrap sub-processes output handling in a thread and pass messages
+    /// back over a channel.
+    cargo_handle: Option<CargoHandle>,
+}
+
+enum Event {
+    Restart(Restart),
+    CheckEvent(Option<cargo_metadata::Message>),
+}
+
+impl FlycheckActor {
+    fn new(
+        sender: Box<dyn Fn(Message) + Send>,
+        config: FlycheckConfig,
+        workspace_root: PathBuf,
+    ) -> FlycheckActor {
+        FlycheckActor { sender, config, workspace_root, cargo_handle: None }
+    }
+    fn next_event(&self, inbox: &Receiver<Restart>) -> Option<Event> {
+        let check_chan = self.cargo_handle.as_ref().map(|cargo| &cargo.receiver);
+        select! {
+            recv(inbox) -> msg => msg.ok().map(Event::Restart),
+            recv(check_chan.unwrap_or(&never())) -> msg => Some(Event::CheckEvent(msg.ok())),
+        }
+    }
+    fn run(mut self, inbox: Receiver<Restart>) {
+        while let Some(event) = self.next_event(&inbox) {
+            match event {
+                Event::Restart(Restart) => {
+                    while let Ok(Restart) = inbox.recv_timeout(Duration::from_millis(50)) {}
+
+                    self.cancel_check_process();
+
+                    let mut command = self.check_command();
+                    log::info!("restart flycheck {:?}", command);
+                    command.stdout(Stdio::piped()).stderr(Stdio::null()).stdin(Stdio::null());
+                    if let Ok(child) = command.spawn().map(JodChild) {
+                        self.cargo_handle = Some(CargoHandle::spawn(child));
+                        self.send(Message::Progress(Progress::DidStart));
+                    }
+                }
+                Event::CheckEvent(None) => {
+                    // Watcher finished, replace it with a never channel to
+                    // avoid busy-waiting.
+                    let cargo_handle = self.cargo_handle.take().unwrap();
+                    let res = cargo_handle.join();
+                    self.send(Message::Progress(Progress::DidFinish(res)));
+                }
+                Event::CheckEvent(Some(message)) => match message {
+                    cargo_metadata::Message::CompilerArtifact(msg) => {
+                        self.send(Message::Progress(Progress::DidCheckCrate(msg.target.name)));
+                    }
+
+                    cargo_metadata::Message::CompilerMessage(msg) => {
+                        self.send(Message::AddDiagnostic {
+                            workspace_root: self.workspace_root.clone(),
+                            diagnostic: msg.message,
+                        });
+                    }
+
+                    cargo_metadata::Message::BuildScriptExecuted(_)
+                    | cargo_metadata::Message::BuildFinished(_)
+                    | cargo_metadata::Message::TextLine(_)
+                    | cargo_metadata::Message::Unknown => {}
+                },
+            }
+        }
+        // If we rerun the thread, we need to discard the previous check results first
+        self.cancel_check_process();
+    }
+    fn cancel_check_process(&mut self) {
+        if self.cargo_handle.take().is_some() {
+            self.send(Message::Progress(Progress::DidCancel));
+        }
+    }
+    fn check_command(&self) -> Command {
+        let mut cmd = match &self.config {
+            FlycheckConfig::CargoCommand {
+                command,
+                all_targets,
+                all_features,
+                extra_args,
+                features,
+            } => {
+                let mut cmd = Command::new(ra_toolchain::cargo());
+                cmd.arg(command);
+                cmd.args(&["--workspace", "--message-format=json", "--manifest-path"])
+                    .arg(self.workspace_root.join("Cargo.toml"));
+                if *all_targets {
+                    cmd.arg("--all-targets");
+                }
+                if *all_features {
+                    cmd.arg("--all-features");
+                } else if !features.is_empty() {
+                    cmd.arg("--features");
+                    cmd.arg(features.join(" "));
+                }
+                cmd.args(extra_args);
+                cmd
+            }
+            FlycheckConfig::CustomCommand { command, args } => {
+                let mut cmd = Command::new(command);
+                cmd.args(args);
+                cmd
+            }
+        };
+        cmd.current_dir(&self.workspace_root);
+        cmd
+    }
+
+    fn send(&self, check_task: Message) {
+        (self.sender)(check_task)
+    }
+}
+
+struct CargoHandle {
+    child: JodChild,
+    #[allow(unused)]
+    thread: jod_thread::JoinHandle<io::Result<bool>>,
+    receiver: Receiver<cargo_metadata::Message>,
+}
+
+impl CargoHandle {
+    fn spawn(mut child: JodChild) -> CargoHandle {
+        let child_stdout = child.stdout.take().unwrap();
+        let (sender, receiver) = unbounded();
+        let actor = CargoActor::new(child_stdout, sender);
+        let thread = jod_thread::spawn(move || actor.run());
+        CargoHandle { child, thread, receiver }
+    }
+    fn join(mut self) -> io::Result<()> {
+        // It is okay to ignore the result, as it only errors if the process is already dead
+        let _ = self.child.kill();
+        let exit_status = self.child.wait()?;
+        let read_at_least_one_message = self.thread.join()?;
+        if !exit_status.success() && !read_at_least_one_message {
+            // FIXME: Read the stderr to display the reason, see `read2()` reference in PR comment:
+            // https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298
+            return Err(io::Error::new(
+                io::ErrorKind::Other,
+                format!(
+                    "Cargo watcher failed,the command produced no valid metadata (exit code: {:?})",
+                    exit_status
+                ),
+            ));
+        }
+        Ok(())
+    }
+}
+
+struct CargoActor {
+    child_stdout: process::ChildStdout,
+    sender: Sender<cargo_metadata::Message>,
+}
+
+impl CargoActor {
+    fn new(
+        child_stdout: process::ChildStdout,
+        sender: Sender<cargo_metadata::Message>,
+    ) -> CargoActor {
+        CargoActor { child_stdout, sender }
+    }
+    fn run(self) -> io::Result<bool> {
+        // We manually read a line at a time, instead of using serde's
+        // stream deserializers, because the deserializer cannot recover
+        // from an error, resulting in it getting stuck, because we try to
+        // be resilient against failures.
+        //
+        // Because cargo only outputs one JSON object per line, we can
+        // simply skip a line if it doesn't parse, which just ignores any
+        // erroneus output.
+        let stdout = BufReader::new(self.child_stdout);
+        let mut read_at_least_one_message = false;
+        for message in cargo_metadata::Message::parse_stream(stdout) {
+            let message = match message {
+                Ok(message) => message,
+                Err(err) => {
+                    log::error!("Invalid json from cargo check, ignoring ({})", err);
+                    continue;
+                }
+            };
+
+            read_at_least_one_message = true;
+
+            // Skip certain kinds of messages to only spend time on what's useful
+            match &message {
+                cargo_metadata::Message::CompilerArtifact(artifact) if artifact.fresh => (),
+                cargo_metadata::Message::BuildScriptExecuted(_)
+                | cargo_metadata::Message::Unknown => (),
+                _ => self.sender.send(message).unwrap(),
+            }
+        }
+        Ok(read_at_least_one_message)
+    }
+}
+
+struct JodChild(process::Child);
+
+impl ops::Deref for JodChild {
+    type Target = process::Child;
+    fn deref(&self) -> &process::Child {
+        &self.0
+    }
+}
+
+impl ops::DerefMut for JodChild {
+    fn deref_mut(&mut self) -> &mut process::Child {
+        &mut self.0
+    }
+}
+
+impl Drop for JodChild {
+    fn drop(&mut self) {
+        let _ = self.0.kill();
+    }
+}
diff --git a/crates/paths/Cargo.toml b/crates/paths/Cargo.toml
new file mode 100644
index 000000000..cbe2c26e2
--- /dev/null
+++ b/crates/paths/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "paths"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
diff --git a/crates/paths/src/lib.rs b/crates/paths/src/lib.rs
new file mode 100644
index 000000000..1b259682d
--- /dev/null
+++ b/crates/paths/src/lib.rs
@@ -0,0 +1,217 @@
+//! Thin wrappers around `std::path`, distinguishing between absolute and
+//! relative paths.
+use std::{
+    convert::{TryFrom, TryInto},
+    ops,
+    path::{Component, Path, PathBuf},
+};
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct AbsPathBuf(PathBuf);
+
+impl From<AbsPathBuf> for PathBuf {
+    fn from(AbsPathBuf(path_buf): AbsPathBuf) -> PathBuf {
+        path_buf
+    }
+}
+
+impl ops::Deref for AbsPathBuf {
+    type Target = AbsPath;
+    fn deref(&self) -> &AbsPath {
+        self.as_path()
+    }
+}
+
+impl AsRef<Path> for AbsPathBuf {
+    fn as_ref(&self) -> &Path {
+        self.0.as_path()
+    }
+}
+
+impl AsRef<AbsPath> for AbsPathBuf {
+    fn as_ref(&self) -> &AbsPath {
+        self.as_path()
+    }
+}
+
+impl TryFrom<PathBuf> for AbsPathBuf {
+    type Error = PathBuf;
+    fn try_from(path_buf: PathBuf) -> Result<AbsPathBuf, PathBuf> {
+        if !path_buf.is_absolute() {
+            return Err(path_buf);
+        }
+        Ok(AbsPathBuf(path_buf))
+    }
+}
+
+impl TryFrom<&str> for AbsPathBuf {
+    type Error = PathBuf;
+    fn try_from(path: &str) -> Result<AbsPathBuf, PathBuf> {
+        AbsPathBuf::try_from(PathBuf::from(path))
+    }
+}
+
+impl PartialEq<AbsPath> for AbsPathBuf {
+    fn eq(&self, other: &AbsPath) -> bool {
+        self.as_path() == other
+    }
+}
+
+impl AbsPathBuf {
+    pub fn assert(path: PathBuf) -> AbsPathBuf {
+        AbsPathBuf::try_from(path)
+            .unwrap_or_else(|path| panic!("expected absolute path, got {}", path.display()))
+    }
+    pub fn as_path(&self) -> &AbsPath {
+        AbsPath::assert(self.0.as_path())
+    }
+    pub fn pop(&mut self) -> bool {
+        self.0.pop()
+    }
+}
+
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
+#[repr(transparent)]
+pub struct AbsPath(Path);
+
+impl ops::Deref for AbsPath {
+    type Target = Path;
+    fn deref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl AsRef<Path> for AbsPath {
+    fn as_ref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl<'a> TryFrom<&'a Path> for &'a AbsPath {
+    type Error = &'a Path;
+    fn try_from(path: &'a Path) -> Result<&'a AbsPath, &'a Path> {
+        if !path.is_absolute() {
+            return Err(path);
+        }
+        Ok(AbsPath::assert(path))
+    }
+}
+
+impl AbsPath {
+    pub fn assert(path: &Path) -> &AbsPath {
+        assert!(path.is_absolute());
+        unsafe { &*(path as *const Path as *const AbsPath) }
+    }
+
+    pub fn parent(&self) -> Option<&AbsPath> {
+        self.0.parent().map(AbsPath::assert)
+    }
+    pub fn join(&self, path: impl AsRef<Path>) -> AbsPathBuf {
+        self.as_ref().join(path).try_into().unwrap()
+    }
+    pub fn normalize(&self) -> AbsPathBuf {
+        AbsPathBuf(normalize_path(&self.0))
+    }
+    pub fn to_path_buf(&self) -> AbsPathBuf {
+        AbsPathBuf::try_from(self.0.to_path_buf()).unwrap()
+    }
+    pub fn strip_prefix(&self, base: &AbsPath) -> Option<&RelPath> {
+        self.0.strip_prefix(base).ok().map(RelPath::new_unchecked)
+    }
+}
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct RelPathBuf(PathBuf);
+
+impl From<RelPathBuf> for PathBuf {
+    fn from(RelPathBuf(path_buf): RelPathBuf) -> PathBuf {
+        path_buf
+    }
+}
+
+impl ops::Deref for RelPathBuf {
+    type Target = RelPath;
+    fn deref(&self) -> &RelPath {
+        self.as_path()
+    }
+}
+
+impl AsRef<Path> for RelPathBuf {
+    fn as_ref(&self) -> &Path {
+        self.0.as_path()
+    }
+}
+
+impl TryFrom<PathBuf> for RelPathBuf {
+    type Error = PathBuf;
+    fn try_from(path_buf: PathBuf) -> Result<RelPathBuf, PathBuf> {
+        if !path_buf.is_relative() {
+            return Err(path_buf);
+        }
+        Ok(RelPathBuf(path_buf))
+    }
+}
+
+impl TryFrom<&str> for RelPathBuf {
+    type Error = PathBuf;
+    fn try_from(path: &str) -> Result<RelPathBuf, PathBuf> {
+        RelPathBuf::try_from(PathBuf::from(path))
+    }
+}
+
+impl RelPathBuf {
+    pub fn as_path(&self) -> &RelPath {
+        RelPath::new_unchecked(self.0.as_path())
+    }
+}
+
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
+#[repr(transparent)]
+pub struct RelPath(Path);
+
+impl ops::Deref for RelPath {
+    type Target = Path;
+    fn deref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl AsRef<Path> for RelPath {
+    fn as_ref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl RelPath {
+    pub fn new_unchecked(path: &Path) -> &RelPath {
+        unsafe { &*(path as *const Path as *const RelPath) }
+    }
+}
+
+// https://github.com/rust-lang/cargo/blob/79c769c3d7b4c2cf6a93781575b7f592ef974255/src/cargo/util/paths.rs#L60-L85
+fn normalize_path(path: &Path) -> PathBuf {
+    let mut components = path.components().peekable();
+    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
+        components.next();
+        PathBuf::from(c.as_os_str())
+    } else {
+        PathBuf::new()
+    };
+
+    for component in components {
+        match component {
+            Component::Prefix(..) => unreachable!(),
+            Component::RootDir => {
+                ret.push(component.as_os_str());
+            }
+            Component::CurDir => {}
+            Component::ParentDir => {
+                ret.pop();
+            }
+            Component::Normal(c) => {
+                ret.push(c);
+            }
+        }
+    }
+    ret
+}
diff --git a/crates/ra_arena/Cargo.toml b/crates/ra_arena/Cargo.toml
index d287dbb73..66c3738f4 100644
--- a/crates/ra_arena/Cargo.toml
+++ b/crates/ra_arena/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_arena"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_arena/src/lib.rs b/crates/ra_arena/src/lib.rs
index 441fbb3cb..3169aa5b8 100644
--- a/crates/ra_arena/src/lib.rs
+++ b/crates/ra_arena/src/lib.rs
@@ -116,6 +116,9 @@ impl<T> Arena<T> {
     ) -> impl Iterator<Item = (Idx<T>, &T)> + ExactSizeIterator + DoubleEndedIterator {
         self.data.iter().enumerate().map(|(idx, value)| (Idx::from_raw(RawId(idx as u32)), value))
     }
+    pub fn shrink_to_fit(&mut self) {
+        self.data.shrink_to_fit();
+    }
 }
 
 impl<T> Default for Arena<T> {
diff --git a/crates/ra_assists/Cargo.toml b/crates/ra_assists/Cargo.toml
index 3bcf58ba4..bd2905f08 100644
--- a/crates/ra_assists/Cargo.toml
+++ b/crates/ra_assists/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_assists"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_assists/src/assist_config.rs b/crates/ra_assists/src/assist_config.rs
index c0a0226fb..cda2abfb9 100644
--- a/crates/ra_assists/src/assist_config.rs
+++ b/crates/ra_assists/src/assist_config.rs
@@ -4,9 +4,12 @@
 //! module, and we use to statically check that we only produce snippet
 //! assists if we are allowed to.
 
+use crate::AssistKind;
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct AssistConfig {
     pub snippet_cap: Option<SnippetCap>,
+    pub allowed: Option<Vec<AssistKind>>,
 }
 
 impl AssistConfig {
@@ -22,6 +25,6 @@ pub struct SnippetCap {
 
 impl Default for AssistConfig {
     fn default() -> Self {
-        AssistConfig { snippet_cap: Some(SnippetCap { _private: () }) }
+        AssistConfig { snippet_cap: Some(SnippetCap { _private: () }), allowed: None }
     }
 }
diff --git a/crates/ra_assists/src/assist_context.rs b/crates/ra_assists/src/assist_context.rs
index 5b1a4680b..3407df856 100644
--- a/crates/ra_assists/src/assist_context.rs
+++ b/crates/ra_assists/src/assist_context.rs
@@ -1,5 +1,7 @@
 //! See `AssistContext`
 
+use std::mem;
+
 use algo::find_covering_element;
 use hir::Semantics;
 use ra_db::{FileId, FileRange};
@@ -17,7 +19,7 @@ use ra_text_edit::TextEditBuilder;
 
 use crate::{
     assist_config::{AssistConfig, SnippetCap},
-    Assist, AssistId, GroupLabel, ResolvedAssist,
+    Assist, AssistId, AssistKind, GroupLabel, ResolvedAssist,
 };
 
 /// `AssistContext` allows to apply an assist or check if it could be applied.
@@ -53,7 +55,6 @@ use crate::{
 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,
     source_file: SourceFile,
 }
@@ -65,8 +66,11 @@ impl<'a> AssistContext<'a> {
         frange: FileRange,
     ) -> AssistContext<'a> {
         let source_file = sema.parse(frange.file_id);
-        let db = sema.db;
-        AssistContext { config, sema, db, frange, source_file }
+        AssistContext { config, sema, frange, source_file }
+    }
+
+    pub(crate) fn db(&self) -> &RootDatabase {
+        self.sema.db
     }
 
     // NB, this ignores active selection.
@@ -99,14 +103,26 @@ pub(crate) struct Assists {
     resolve: bool,
     file: FileId,
     buf: Vec<(Assist, Option<SourceChange>)>,
+    allowed: Option<Vec<AssistKind>>,
 }
 
 impl Assists {
     pub(crate) fn new_resolved(ctx: &AssistContext) -> Assists {
-        Assists { resolve: true, file: ctx.frange.file_id, buf: Vec::new() }
+        Assists {
+            resolve: true,
+            file: ctx.frange.file_id,
+            buf: Vec::new(),
+            allowed: ctx.config.allowed.clone(),
+        }
     }
+
     pub(crate) fn new_unresolved(ctx: &AssistContext) -> Assists {
-        Assists { resolve: false, file: ctx.frange.file_id, buf: Vec::new() }
+        Assists {
+            resolve: false,
+            file: ctx.frange.file_id,
+            buf: Vec::new(),
+            allowed: ctx.config.allowed.clone(),
+        }
     }
 
     pub(crate) fn finish_unresolved(self) -> Vec<Assist> {
@@ -135,9 +151,13 @@ impl Assists {
         target: TextRange,
         f: impl FnOnce(&mut AssistBuilder),
     ) -> Option<()> {
+        if !self.is_allowed(&id) {
+            return None;
+        }
         let label = Assist::new(id, label.into(), None, target);
         self.add_impl(label, f)
     }
+
     pub(crate) fn add_group(
         &mut self,
         group: &GroupLabel,
@@ -146,9 +166,14 @@ impl Assists {
         target: TextRange,
         f: impl FnOnce(&mut AssistBuilder),
     ) -> Option<()> {
+        if !self.is_allowed(&id) {
+            return None;
+        }
+
         let label = Assist::new(id, label.into(), Some(group.clone()), target);
         self.add_impl(label, f)
     }
+
     fn add_impl(&mut self, label: Assist, f: impl FnOnce(&mut AssistBuilder)) -> Option<()> {
         let source_change = if self.resolve {
             let mut builder = AssistBuilder::new(self.file);
@@ -166,17 +191,43 @@ impl Assists {
         self.buf.sort_by_key(|(label, _edit)| label.target.len());
         self.buf
     }
+
+    fn is_allowed(&self, id: &AssistId) -> bool {
+        match &self.allowed {
+            Some(allowed) => allowed.iter().any(|kind| kind.contains(id.1)),
+            None => true,
+        }
+    }
 }
 
 pub(crate) struct AssistBuilder {
     edit: TextEditBuilder,
-    file: FileId,
+    file_id: FileId,
     is_snippet: bool,
+    change: SourceChange,
 }
 
 impl AssistBuilder {
-    pub(crate) fn new(file: FileId) -> AssistBuilder {
-        AssistBuilder { edit: TextEditBuilder::default(), file, is_snippet: false }
+    pub(crate) fn new(file_id: FileId) -> AssistBuilder {
+        AssistBuilder {
+            edit: TextEditBuilder::default(),
+            file_id,
+            is_snippet: false,
+            change: SourceChange::default(),
+        }
+    }
+
+    pub(crate) fn edit_file(&mut self, file_id: FileId) {
+        self.file_id = file_id;
+    }
+
+    fn commit(&mut self) {
+        let edit = mem::take(&mut self.edit).finish();
+        if !edit.is_empty() {
+            let new_edit = SourceFileEdit { file_id: self.file_id, edit };
+            assert!(!self.change.source_file_edits.iter().any(|it| it.file_id == new_edit.file_id));
+            self.change.source_file_edits.push(new_edit);
+        }
     }
 
     /// Remove specified `range` of text.
@@ -231,12 +282,7 @@ impl AssistBuilder {
     pub(crate) fn rewrite(&mut self, rewriter: SyntaxRewriter) {
         let node = rewriter.rewrite_root().unwrap();
         let new = rewriter.rewrite(&node);
-        algo::diff(&node, &new).into_text_edit(&mut self.edit)
-    }
-
-    // FIXME: better API
-    pub(crate) fn set_file(&mut self, assist_file: FileId) {
-        self.file = assist_file;
+        algo::diff(&node, &new).into_text_edit(&mut self.edit);
     }
 
     // FIXME: kill this API
@@ -245,13 +291,12 @@ impl AssistBuilder {
         &mut self.edit
     }
 
-    fn finish(self) -> SourceChange {
-        let edit = self.edit.finish();
-        let source_file_edit = SourceFileEdit { file_id: self.file, edit };
-        let mut res: SourceChange = source_file_edit.into();
+    fn finish(mut self) -> SourceChange {
+        self.commit();
+        let mut change = mem::take(&mut self.change);
         if self.is_snippet {
-            res.is_snippet = true;
+            change.is_snippet = true;
         }
-        res
+        change
     }
 }
diff --git a/crates/ra_assists/src/ast_transform.rs b/crates/ra_assists/src/ast_transform.rs
index 3079a02a2..01adb834c 100644
--- a/crates/ra_assists/src/ast_transform.rs
+++ b/crates/ra_assists/src/ast_transform.rs
@@ -2,7 +2,6 @@
 use rustc_hash::FxHashMap;
 
 use hir::{HirDisplay, PathResolution, SemanticsScope};
-use ra_ide_db::RootDatabase;
 use ra_syntax::{
     algo::SyntaxRewriter,
     ast::{self, AstNode},
@@ -32,14 +31,14 @@ impl<'a> AstTransform<'a> for NullTransformer {
 }
 
 pub struct SubstituteTypeParams<'a> {
-    source_scope: &'a SemanticsScope<'a, RootDatabase>,
+    source_scope: &'a SemanticsScope<'a>,
     substs: FxHashMap<hir::TypeParam, ast::TypeRef>,
     previous: Box<dyn AstTransform<'a> + 'a>,
 }
 
 impl<'a> SubstituteTypeParams<'a> {
     pub fn for_trait_impl(
-        source_scope: &'a SemanticsScope<'a, RootDatabase>,
+        source_scope: &'a SemanticsScope<'a>,
         // FIXME: there's implicit invariant that `trait_` and  `source_scope` match...
         trait_: hir::Trait,
         impl_def: ast::ImplDef,
@@ -106,6 +105,7 @@ impl<'a> SubstituteTypeParams<'a> {
             _ => return None,
         };
         // FIXME: use `hir::Path::from_src` instead.
+        #[allow(deprecated)]
         let path = hir::Path::from_ast(path)?;
         let resolution = self.source_scope.resolve_hir_path(&path)?;
         match resolution {
@@ -125,16 +125,13 @@ impl<'a> AstTransform<'a> for SubstituteTypeParams<'a> {
 }
 
 pub struct QualifyPaths<'a> {
-    target_scope: &'a SemanticsScope<'a, RootDatabase>,
-    source_scope: &'a SemanticsScope<'a, RootDatabase>,
+    target_scope: &'a SemanticsScope<'a>,
+    source_scope: &'a SemanticsScope<'a>,
     previous: Box<dyn AstTransform<'a> + 'a>,
 }
 
 impl<'a> QualifyPaths<'a> {
-    pub fn new(
-        target_scope: &'a SemanticsScope<'a, RootDatabase>,
-        source_scope: &'a SemanticsScope<'a, RootDatabase>,
-    ) -> Self {
+    pub fn new(target_scope: &'a SemanticsScope<'a>, source_scope: &'a SemanticsScope<'a>) -> Self {
         Self { target_scope, source_scope, previous: Box::new(NullTransformer) }
     }
 
@@ -150,11 +147,12 @@ impl<'a> QualifyPaths<'a> {
             return None;
         }
         // FIXME: use `hir::Path::from_src` instead.
+        #[allow(deprecated)]
         let hir_path = hir::Path::from_ast(p.clone());
         let resolution = self.source_scope.resolve_hir_path(&hir_path?)?;
         match resolution {
             PathResolution::Def(def) => {
-                let found_path = from.find_use_path(self.source_scope.db, def)?;
+                let found_path = from.find_use_path(self.source_scope.db.upcast(), def)?;
                 let mut path = path_to_ast(found_path);
 
                 let type_args = p
diff --git a/crates/ra_assists/src/handlers/add_custom_impl.rs b/crates/ra_assists/src/handlers/add_custom_impl.rs
index fa70c8496..acb07e36a 100644
--- a/crates/ra_assists/src/handlers/add_custom_impl.rs
+++ b/crates/ra_assists/src/handlers/add_custom_impl.rs
@@ -8,7 +8,7 @@ use stdx::SepBy;
 
 use crate::{
     assist_context::{AssistContext, Assists},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: add_custom_impl
@@ -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, |builder| {
+    acc.add(AssistId("add_custom_impl", AssistKind::Refactor), label, target, |builder| {
         let new_attr_input = input
             .syntax()
             .descendants_with_tokens()
diff --git a/crates/ra_assists/src/handlers/add_explicit_type.rs b/crates/ra_assists/src/handlers/add_explicit_type.rs
index ab20c6649..39a5321d1 100644
--- a/crates/ra_assists/src/handlers/add_explicit_type.rs
+++ b/crates/ra_assists/src/handlers/add_explicit_type.rs
@@ -4,7 +4,7 @@ use ra_syntax::{
     TextRange,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: add_explicit_type
 //
@@ -57,9 +57,9 @@ pub(crate) fn add_explicit_type(acc: &mut Assists, ctx: &AssistContext) -> Optio
         return None;
     }
 
-    let inferred_type = ty.display_source_code(ctx.db, module.into()).ok()?;
+    let inferred_type = ty.display_source_code(ctx.db(), module.into()).ok()?;
     acc.add(
-        AssistId("add_explicit_type"),
+        AssistId("add_explicit_type", AssistKind::RefactorRewrite),
         format!("Insert explicit type `{}`", inferred_type),
         pat_range,
         |builder| match ascribed_ty {
@@ -195,7 +195,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let test<|> = Test { t: 23, k: 33 };
+    let test<|> = Test { t: 23u8, k: 33 };
 }"#,
             r#"
 struct Test<K, T = u8> {
@@ -204,7 +204,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let test: Test<i32> = Test { t: 23, k: 33 };
+    let test: Test<i32> = Test { t: 23u8, k: 33 };
 }"#,
         );
     }
diff --git a/crates/ra_assists/src/handlers/add_impl.rs b/crates/ra_assists/src/handlers/add_impl.rs
deleted file mode 100644
index eceba7d0a..000000000
--- a/crates/ra_assists/src/handlers/add_impl.rs
+++ /dev/null
@@ -1,98 +0,0 @@
-use ra_syntax::ast::{self, AstNode, NameOwner, TypeParamsOwner};
-use stdx::{format_to, SepBy};
-
-use crate::{AssistContext, AssistId, Assists};
-
-// Assist: add_impl
-//
-// Adds a new inherent impl for a type.
-//
-// ```
-// struct Ctx<T: Clone> {
-//     data: T,<|>
-// }
-// ```
-// ->
-// ```
-// struct Ctx<T: Clone> {
-//     data: T,
-// }
-//
-// impl<T: Clone> Ctx<T> {
-//     $0
-// }
-// ```
-pub(crate) fn add_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let nominal = ctx.find_node_at_offset::<ast::NominalDef>()?;
-    let name = nominal.name()?;
-    let target = nominal.syntax().text_range();
-    acc.add(AssistId("add_impl"), format!("Implement {}", name.text().as_str()), target, |edit| {
-        let type_params = nominal.type_param_list();
-        let start_offset = nominal.syntax().text_range().end();
-        let mut buf = String::new();
-        buf.push_str("\n\nimpl");
-        if let Some(type_params) = &type_params {
-            format_to!(buf, "{}", type_params.syntax());
-        }
-        buf.push_str(" ");
-        buf.push_str(name.text().as_str());
-        if let Some(type_params) = type_params {
-            let lifetime_params = type_params
-                .lifetime_params()
-                .filter_map(|it| it.lifetime_token())
-                .map(|it| it.text().clone());
-            let type_params =
-                type_params.type_params().filter_map(|it| it.name()).map(|it| it.text().clone());
-
-            let generic_params = lifetime_params.chain(type_params).sep_by(", ");
-            format_to!(buf, "<{}>", generic_params)
-        }
-        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 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    $0\n}\n");
-        check_assist(
-            add_impl,
-            "struct Foo<T: Clone> {<|>}",
-            "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    $0\n}",
-        );
-    }
-
-    #[test]
-    fn add_impl_target() {
-        check_assist_target(
-            add_impl,
-            "
-struct SomeThingIrrelevant;
-/// Has a lifetime parameter
-struct Foo<'a, T: Foo<'a>> {<|>}
-struct EvenMoreIrrelevant;
-",
-            "/// Has a lifetime parameter
-struct Foo<'a, T: Foo<'a>> {}",
-        );
-    }
-}
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 abacd4065..f185e61e5 100644
--- a/crates/ra_assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
@@ -12,7 +12,7 @@ use crate::{
     assist_context::{AssistContext, Assists},
     ast_transform::{self, AstTransform, QualifyPaths, SubstituteTypeParams},
     utils::{get_missing_assoc_items, render_snippet, resolve_target_trait, Cursor},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 #[derive(PartialEq)]
@@ -128,9 +128,9 @@ fn add_missing_impl_members_inner(
     let missing_items = get_missing_assoc_items(&ctx.sema, &impl_def)
         .iter()
         .map(|i| match i {
-            hir::AssocItem::Function(i) => ast::AssocItem::FnDef(i.source(ctx.db).value),
-            hir::AssocItem::TypeAlias(i) => ast::AssocItem::TypeAliasDef(i.source(ctx.db).value),
-            hir::AssocItem::Const(i) => ast::AssocItem::ConstDef(i.source(ctx.db).value),
+            hir::AssocItem::Function(i) => ast::AssocItem::FnDef(i.source(ctx.db()).value),
+            hir::AssocItem::TypeAlias(i) => ast::AssocItem::TypeAliasDef(i.source(ctx.db()).value),
+            hir::AssocItem::Const(i) => ast::AssocItem::ConstDef(i.source(ctx.db()).value),
         })
         .filter(|t| def_name(&t).is_some())
         .filter(|t| match t {
@@ -147,7 +147,7 @@ fn add_missing_impl_members_inner(
     }
 
     let target = impl_def.syntax().text_range();
-    acc.add(AssistId(assist_id), label, target, |builder| {
+    acc.add(AssistId(assist_id, AssistKind::QuickFix), 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());
@@ -158,6 +158,9 @@ fn add_missing_impl_members_inner(
             .map(|it| ast_transform::apply(&*ast_transform, it))
             .map(|it| match it {
                 ast::AssocItem::FnDef(def) => ast::AssocItem::FnDef(add_body(def)),
+                ast::AssocItem::TypeAliasDef(def) => {
+                    ast::AssocItem::TypeAliasDef(def.remove_bounds())
+                }
                 _ => it,
             })
             .map(|it| edit::remove_attrs_and_docs(&it));
@@ -684,4 +687,26 @@ impl Foo<T> for S<T> {
 }"#,
         )
     }
+
+    #[test]
+    fn test_assoc_type_bounds_are_removed() {
+        check_assist(
+            add_missing_impl_members,
+            r#"
+trait Tr {
+    type Ty: Copy + 'static;
+}
+
+impl Tr for ()<|> {
+}"#,
+            r#"
+trait Tr {
+    type Ty: Copy + 'static;
+}
+
+impl Tr for () {
+    $0type Ty;
+}"#,
+        )
+    }
 }
diff --git a/crates/ra_assists/src/handlers/add_turbo_fish.rs b/crates/ra_assists/src/handlers/add_turbo_fish.rs
index 26acf81f2..f7e1a7b05 100644
--- a/crates/ra_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ra_assists/src/handlers/add_turbo_fish.rs
@@ -4,7 +4,7 @@ use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: add_turbo_fish
@@ -45,12 +45,15 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
         mark::hit!(add_turbo_fish_non_generic);
         return None;
     }
-    acc.add(AssistId("add_turbo_fish"), "Add `::<>`", ident.text_range(), |builder| {
-        match ctx.config.snippet_cap {
+    acc.add(
+        AssistId("add_turbo_fish", AssistKind::RefactorRewrite),
+        "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)]
diff --git a/crates/ra_assists/src/handlers/apply_demorgan.rs b/crates/ra_assists/src/handlers/apply_demorgan.rs
index 233e8fb8e..de701f8b8 100644
--- a/crates/ra_assists/src/handlers/apply_demorgan.rs
+++ b/crates/ra_assists/src/handlers/apply_demorgan.rs
@@ -1,6 +1,6 @@
 use ra_syntax::ast::{self, AstNode};
 
-use crate::{utils::invert_boolean_expression, AssistContext, AssistId, Assists};
+use crate::{utils::invert_boolean_expression, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: apply_demorgan
 //
@@ -39,11 +39,16 @@ pub(crate) fn apply_demorgan(acc: &mut Assists, ctx: &AssistContext) -> Option<(
     let rhs_range = rhs.syntax().text_range();
     let not_rhs = invert_boolean_expression(rhs);
 
-    acc.add(AssistId("apply_demorgan"), "Apply De Morgan's law", op_range, |edit| {
-        edit.replace(op_range, opposite_op);
-        edit.replace(lhs_range, format!("!({}", not_lhs.syntax().text()));
-        edit.replace(rhs_range, format!("{})", not_rhs.syntax().text()));
-    })
+    acc.add(
+        AssistId("apply_demorgan", AssistKind::RefactorRewrite),
+        "Apply De Morgan's law",
+        op_range,
+        |edit| {
+            edit.replace(op_range, opposite_op);
+            edit.replace(lhs_range, format!("!({}", not_lhs.syntax().text()));
+            edit.replace(rhs_range, format!("{})", not_rhs.syntax().text()));
+        },
+    )
 }
 
 // Return the opposite text for a given logical operator, if it makes sense
diff --git a/crates/ra_assists/src/handlers/auto_import.rs b/crates/ra_assists/src/handlers/auto_import.rs
index edf96d50e..947be3b9b 100644
--- a/crates/ra_assists/src/handlers/auto_import.rs
+++ b/crates/ra_assists/src/handlers/auto_import.rs
@@ -5,7 +5,7 @@ use hir::{
     AsAssocItem, AssocItemContainer, ModPath, Module, ModuleDef, PathResolution, Semantics, Trait,
     Type,
 };
-use ra_ide_db::{imports_locator::ImportsLocator, RootDatabase};
+use ra_ide_db::{imports_locator, RootDatabase};
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode},
@@ -13,7 +13,9 @@ use ra_syntax::{
 };
 use rustc_hash::FxHashSet;
 
-use crate::{utils::insert_use_statement, AssistContext, AssistId, Assists, GroupLabel};
+use crate::{
+    utils::insert_use_statement, AssistContext, AssistId, AssistKind, Assists, GroupLabel,
+};
 
 // Assist: auto_import
 //
@@ -35,8 +37,8 @@ use crate::{utils::insert_use_statement, AssistContext, AssistId, Assists, Group
 // # pub mod std { pub mod collections { pub struct HashMap { } } }
 // ```
 pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let auto_import_assets = AutoImportAssets::new(&ctx)?;
-    let proposed_imports = auto_import_assets.search_for_imports(ctx.db);
+    let auto_import_assets = AutoImportAssets::new(ctx)?;
+    let proposed_imports = auto_import_assets.search_for_imports(ctx);
     if proposed_imports.is_empty() {
         return None;
     }
@@ -46,7 +48,7 @@ pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     for import in proposed_imports {
         acc.add_group(
             &group,
-            AssistId("auto_import"),
+            AssistId("auto_import", AssistKind::QuickFix),
             format!("Import `{}`", &import),
             range,
             |builder| {
@@ -127,11 +129,11 @@ impl AutoImportAssets {
         GroupLabel(name)
     }
 
-    fn search_for_imports(&self, db: &RootDatabase) -> BTreeSet<ModPath> {
+    fn search_for_imports(&self, ctx: &AssistContext) -> BTreeSet<ModPath> {
         let _p = profile("auto_import::search_for_imports");
+        let db = ctx.db();
         let current_crate = self.module_with_name_to_import.krate();
-        ImportsLocator::new(db)
-            .find_imports(&self.get_search_query())
+        imports_locator::find_imports(&ctx.sema, current_crate, &self.get_search_query())
             .into_iter()
             .filter_map(|candidate| match &self.import_candidate {
                 ImportCandidate::TraitAssocItem(assoc_item_type, _) => {
@@ -488,16 +490,17 @@ mod tests {
         check_assist(
             auto_import,
             r"
-                    //- /lib.rs crate:crate_with_macro
-                    #[macro_export]
-                    macro_rules! foo {
-                        () => ()
-                    }
+//- /lib.rs crate:crate_with_macro
+#[macro_export]
+macro_rules! foo {
+    () => ()
+}
 
-                    //- /main.rs crate:main deps:crate_with_macro
-                    fn main() {
-                        foo<|>
-                    }",
+//- /main.rs crate:main deps:crate_with_macro
+fn main() {
+    foo<|>
+}
+",
             r"use crate_with_macro::foo;
 
 fn main() {
@@ -810,6 +813,146 @@ fn main() {
     }
 
     #[test]
+    fn trait_method_cross_crate() {
+        check_assist(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_meth<|>od()
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_method(&self) {}
+                }
+            }
+            ",
+            r"
+            use dep::test_mod::TestTrait;
+
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_method()
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn assoc_fn_cross_crate() {
+        check_assist(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                dep::test_mod::TestStruct::test_func<|>tion
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_function() {}
+                }
+            }
+            ",
+            r"
+            use dep::test_mod::TestTrait;
+
+            fn main() {
+                dep::test_mod::TestStruct::test_function
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn assoc_const_cross_crate() {
+        check_assist(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                dep::test_mod::TestStruct::CONST<|>
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    const CONST: bool;
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    const CONST: bool = true;
+                }
+            }
+            ",
+            r"
+            use dep::test_mod::TestTrait;
+
+            fn main() {
+                dep::test_mod::TestStruct::CONST
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn assoc_fn_as_method_cross_crate() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_func<|>tion()
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_function() {}
+                }
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn private_trait_cross_crate() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_meth<|>od()
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_method(&self) {}
+                }
+            }
+            ",
+        );
+    }
+
+    #[test]
     fn not_applicable_for_imported_trait_for_method() {
         check_assist_not_applicable(
             auto_import,
@@ -841,4 +984,106 @@ fn main() {
             ",
         )
     }
+
+    #[test]
+    fn dep_import() {
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+pub struct Struct;
+
+//- /main.rs crate:main deps:dep
+fn main() {
+    Struct<|>
+}
+",
+            r"use dep::Struct;
+
+fn main() {
+    Struct
+}
+",
+        );
+    }
+
+    #[test]
+    fn whole_segment() {
+        // Tests that only imports whose last segment matches the identifier get suggested.
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+pub mod fmt {
+    pub trait Display {}
+}
+
+pub fn panic_fmt() {}
+
+//- /main.rs crate:main deps:dep
+struct S;
+
+impl f<|>mt::Display for S {}
+",
+            r"use dep::fmt;
+
+struct S;
+
+impl fmt::Display for S {}
+",
+        );
+    }
+
+    #[test]
+    fn macro_generated() {
+        // Tests that macro-generated items are suggested from external crates.
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+macro_rules! mac {
+    () => {
+        pub struct Cheese;
+    };
+}
+
+mac!();
+
+//- /main.rs crate:main deps:dep
+fn main() {
+    Cheese<|>;
+}
+",
+            r"use dep::Cheese;
+
+fn main() {
+    Cheese;
+}
+",
+        );
+    }
+
+    #[test]
+    fn casing() {
+        // Tests that differently cased names don't interfere and we only suggest the matching one.
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+pub struct FMT;
+pub struct fmt;
+
+//- /main.rs crate:main deps:dep
+fn main() {
+    FMT<|>;
+}
+",
+            r"use dep::FMT;
+
+fn main() {
+    FMT;
+}
+",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/change_return_type_to_result.rs b/crates/ra_assists/src/handlers/change_return_type_to_result.rs
index c6baa0a57..24e5f6963 100644
--- a/crates/ra_assists/src/handlers/change_return_type_to_result.rs
+++ b/crates/ra_assists/src/handlers/change_return_type_to_result.rs
@@ -3,7 +3,8 @@ use ra_syntax::{
     AstNode, SyntaxNode,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+use test_utils::mark;
 
 // Assist: change_return_type_to_result
 //
@@ -22,14 +23,19 @@ pub(crate) fn change_return_type_to_result(acc: &mut Assists, ctx: &AssistContex
     let fn_def = ret_type.syntax().parent().and_then(ast::FnDef::cast)?;
 
     let type_ref = &ret_type.type_ref()?;
-    if type_ref.syntax().text().to_string().starts_with("Result<") {
-        return None;
+    let ret_type_str = type_ref.syntax().text().to_string();
+    let first_part_ret_type = ret_type_str.splitn(2, '<').next();
+    if let Some(ret_type_first_part) = first_part_ret_type {
+        if ret_type_first_part.ends_with("Result") {
+            mark::hit!(change_return_type_to_result_simple_return_type_already_result);
+            return None;
+        }
     }
 
     let block_expr = &fn_def.body()?;
 
     acc.add(
-        AssistId("change_return_type_to_result"),
+        AssistId("change_return_type_to_result", AssistKind::RefactorRewrite),
         "Change return type to Result",
         type_ref.syntax().text_range(),
         |builder| {
@@ -297,6 +303,29 @@ mod tests {
     }
 
     #[test]
+    fn change_return_type_to_result_simple_return_type_already_result_std() {
+        check_assist_not_applicable(
+            change_return_type_to_result,
+            r#"fn foo() -> std::result::Result<i32<|>, String> {
+                let test = "test";
+                return 42i32;
+            }"#,
+        );
+    }
+
+    #[test]
+    fn change_return_type_to_result_simple_return_type_already_result() {
+        mark::check!(change_return_type_to_result_simple_return_type_already_result);
+        check_assist_not_applicable(
+            change_return_type_to_result,
+            r#"fn foo() -> Result<i32<|>, String> {
+                let test = "test";
+                return 42i32;
+            }"#,
+        );
+    }
+
+    #[test]
     fn change_return_type_to_result_simple_with_cursor() {
         check_assist(
             change_return_type_to_result,
diff --git a/crates/ra_assists/src/handlers/change_visibility.rs b/crates/ra_assists/src/handlers/change_visibility.rs
index c21d75be0..4343b423c 100644
--- a/crates/ra_assists/src/handlers/change_visibility.rs
+++ b/crates/ra_assists/src/handlers/change_visibility.rs
@@ -2,14 +2,13 @@ use ra_syntax::{
     ast::{self, NameOwner, VisibilityOwner},
     AstNode,
     SyntaxKind::{
-        ATTR, COMMENT, CONST_DEF, ENUM_DEF, FN_DEF, MODULE, STRUCT_DEF, TRAIT_DEF, VISIBILITY,
-        WHITESPACE,
+        CONST_DEF, ENUM_DEF, FN_DEF, MODULE, STATIC_DEF, STRUCT_DEF, TRAIT_DEF, VISIBILITY,
     },
-    SyntaxNode, TextSize, T,
+    T,
 };
 use test_utils::mark;
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{utils::vis_offset, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: change_visibility
 //
@@ -30,14 +29,16 @@ pub(crate) fn change_visibility(acc: &mut Assists, ctx: &AssistContext) -> Optio
 }
 
 fn add_vis(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let item_keyword = ctx.token_at_offset().find(|leaf| match leaf.kind() {
-        T![const] | T![fn] | T![mod] | T![struct] | T![enum] | T![trait] => true,
-        _ => false,
+    let item_keyword = ctx.token_at_offset().find(|leaf| {
+        matches!(
+            leaf.kind(),
+            T![const] | T![static] | T![fn] | T![mod] | T![struct] | T![enum] | T![trait]
+        )
     });
 
     let (offset, target) = if let Some(keyword) = item_keyword {
         let parent = keyword.parent();
-        let def_kws = vec![CONST_DEF, FN_DEF, MODULE, STRUCT_DEF, ENUM_DEF, TRAIT_DEF];
+        let def_kws = vec![CONST_DEF, STATIC_DEF, FN_DEF, MODULE, STRUCT_DEF, ENUM_DEF, TRAIT_DEF];
         // Parent is not a definition, can't add visibility
         if !def_kws.iter().any(|&def_kw| def_kw == parent.kind()) {
             return None;
@@ -66,27 +67,21 @@ fn add_vis(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
         return None;
     };
 
-    acc.add(AssistId("change_visibility"), "Change visibility to pub(crate)", target, |edit| {
-        edit.insert(offset, "pub(crate) ");
-    })
-}
-
-fn vis_offset(node: &SyntaxNode) -> TextSize {
-    node.children_with_tokens()
-        .skip_while(|it| match it.kind() {
-            WHITESPACE | COMMENT | ATTR => true,
-            _ => false,
-        })
-        .next()
-        .map(|it| it.text_range().start())
-        .unwrap_or_else(|| node.text_range().start())
+    acc.add(
+        AssistId("change_visibility", AssistKind::RefactorRewrite),
+        "Change visibility to pub(crate)",
+        target,
+        |edit| {
+            edit.insert(offset, "pub(crate) ");
+        },
+    )
 }
 
 fn change_vis(acc: &mut Assists, vis: ast::Visibility) -> Option<()> {
     if vis.syntax().text() == "pub" {
         let target = vis.syntax().text_range();
         return acc.add(
-            AssistId("change_visibility"),
+            AssistId("change_visibility", AssistKind::RefactorRewrite),
             "Change Visibility to pub(crate)",
             target,
             |edit| {
@@ -97,7 +92,7 @@ fn change_vis(acc: &mut Assists, vis: ast::Visibility) -> Option<()> {
     if vis.syntax().text() == "pub(crate)" {
         let target = vis.syntax().text_range();
         return acc.add(
-            AssistId("change_visibility"),
+            AssistId("change_visibility", AssistKind::RefactorRewrite),
             "Change visibility to pub",
             target,
             |edit| {
@@ -162,6 +157,11 @@ mod tests {
     }
 
     #[test]
+    fn change_visibility_static() {
+        check_assist(change_visibility, "<|>static FOO = 3u8;", "pub(crate) static FOO = 3u8;");
+    }
+
+    #[test]
     fn change_visibility_handles_comment_attrs() {
         check_assist(
             change_visibility,
diff --git a/crates/ra_assists/src/handlers/early_return.rs b/crates/ra_assists/src/handlers/early_return.rs
index 4cc75a7ce..330459f3c 100644
--- a/crates/ra_assists/src/handlers/early_return.rs
+++ b/crates/ra_assists/src/handlers/early_return.rs
@@ -15,7 +15,7 @@ use ra_syntax::{
 use crate::{
     assist_context::{AssistContext, Assists},
     utils::invert_boolean_expression,
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: convert_to_guarded_return
@@ -99,86 +99,92 @@ pub(crate) fn convert_to_guarded_return(acc: &mut Assists, ctx: &AssistContext)
     then_block.syntax().last_child_or_token().filter(|t| t.kind() == R_CURLY)?;
 
     let target = if_expr.syntax().text_range();
-    acc.add(AssistId("convert_to_guarded_return"), "Convert to guarded return", target, |edit| {
-        let if_indent_level = IndentLevel::from_node(&if_expr.syntax());
-        let new_block = match if_let_pat {
-            None => {
-                // If.
-                let new_expr = {
-                    let then_branch =
-                        make::block_expr(once(make::expr_stmt(early_expression).into()), None);
-                    let cond = invert_boolean_expression(cond_expr);
-                    make::expr_if(make::condition(cond, None), then_branch).indent(if_indent_level)
-                };
-                replace(new_expr.syntax(), &then_block, &parent_block, &if_expr)
-            }
-            Some((path, bound_ident)) => {
-                // If-let.
-                let match_expr = {
-                    let happy_arm = {
-                        let pat = make::tuple_struct_pat(
-                            path,
-                            once(make::bind_pat(make::name("it")).into()),
-                        );
-                        let expr = {
-                            let name_ref = make::name_ref("it");
-                            let segment = make::path_segment(name_ref);
-                            let path = make::path_unqualified(segment);
-                            make::expr_path(path)
-                        };
-                        make::match_arm(once(pat.into()), expr)
+    acc.add(
+        AssistId("convert_to_guarded_return", AssistKind::RefactorRewrite),
+        "Convert to guarded return",
+        target,
+        |edit| {
+            let if_indent_level = IndentLevel::from_node(&if_expr.syntax());
+            let new_block = match if_let_pat {
+                None => {
+                    // If.
+                    let new_expr = {
+                        let then_branch =
+                            make::block_expr(once(make::expr_stmt(early_expression).into()), None);
+                        let cond = invert_boolean_expression(cond_expr);
+                        make::expr_if(make::condition(cond, None), then_branch)
+                            .indent(if_indent_level)
                     };
+                    replace(new_expr.syntax(), &then_block, &parent_block, &if_expr)
+                }
+                Some((path, bound_ident)) => {
+                    // If-let.
+                    let match_expr = {
+                        let happy_arm = {
+                            let pat = make::tuple_struct_pat(
+                                path,
+                                once(make::bind_pat(make::name("it")).into()),
+                            );
+                            let expr = {
+                                let name_ref = make::name_ref("it");
+                                let segment = make::path_segment(name_ref);
+                                let path = make::path_unqualified(segment);
+                                make::expr_path(path)
+                            };
+                            make::match_arm(once(pat.into()), expr)
+                        };
 
-                    let sad_arm = make::match_arm(
-                        // FIXME: would be cool to use `None` or `Err(_)` if appropriate
-                        once(make::placeholder_pat().into()),
-                        early_expression,
-                    );
+                        let sad_arm = make::match_arm(
+                            // FIXME: would be cool to use `None` or `Err(_)` if appropriate
+                            once(make::placeholder_pat().into()),
+                            early_expression,
+                        );
 
-                    make::expr_match(cond_expr, make::match_arm_list(vec![happy_arm, sad_arm]))
-                };
+                        make::expr_match(cond_expr, make::match_arm_list(vec![happy_arm, sad_arm]))
+                    };
 
-                let let_stmt = make::let_stmt(
-                    make::bind_pat(make::name(&bound_ident.syntax().to_string())).into(),
-                    Some(match_expr),
+                    let let_stmt = make::let_stmt(
+                        make::bind_pat(make::name(&bound_ident.syntax().to_string())).into(),
+                        Some(match_expr),
+                    );
+                    let let_stmt = let_stmt.indent(if_indent_level);
+                    replace(let_stmt.syntax(), &then_block, &parent_block, &if_expr)
+                }
+            };
+            edit.replace_ast(parent_block, ast::BlockExpr::cast(new_block).unwrap());
+
+            fn replace(
+                new_expr: &SyntaxNode,
+                then_block: &ast::BlockExpr,
+                parent_block: &ast::BlockExpr,
+                if_expr: &ast::IfExpr,
+            ) -> SyntaxNode {
+                let then_block_items = then_block.dedent(IndentLevel(1));
+                let end_of_then = then_block_items.syntax().last_child_or_token().unwrap();
+                let end_of_then =
+                    if end_of_then.prev_sibling_or_token().map(|n| n.kind()) == Some(WHITESPACE) {
+                        end_of_then.prev_sibling_or_token().unwrap()
+                    } else {
+                        end_of_then
+                    };
+                let mut then_statements = new_expr.children_with_tokens().chain(
+                    then_block_items
+                        .syntax()
+                        .children_with_tokens()
+                        .skip(1)
+                        .take_while(|i| *i != end_of_then),
                 );
-                let let_stmt = let_stmt.indent(if_indent_level);
-                replace(let_stmt.syntax(), &then_block, &parent_block, &if_expr)
+                replace_children(
+                    &parent_block.syntax(),
+                    RangeInclusive::new(
+                        if_expr.clone().syntax().clone().into(),
+                        if_expr.syntax().clone().into(),
+                    ),
+                    &mut then_statements,
+                )
             }
-        };
-        edit.replace_ast(parent_block, ast::BlockExpr::cast(new_block).unwrap());
-
-        fn replace(
-            new_expr: &SyntaxNode,
-            then_block: &ast::BlockExpr,
-            parent_block: &ast::BlockExpr,
-            if_expr: &ast::IfExpr,
-        ) -> SyntaxNode {
-            let then_block_items = then_block.dedent(IndentLevel::from(1));
-            let end_of_then = then_block_items.syntax().last_child_or_token().unwrap();
-            let end_of_then =
-                if end_of_then.prev_sibling_or_token().map(|n| n.kind()) == Some(WHITESPACE) {
-                    end_of_then.prev_sibling_or_token().unwrap()
-                } else {
-                    end_of_then
-                };
-            let mut then_statements = new_expr.children_with_tokens().chain(
-                then_block_items
-                    .syntax()
-                    .children_with_tokens()
-                    .skip(1)
-                    .take_while(|i| *i != end_of_then),
-            );
-            replace_children(
-                &parent_block.syntax(),
-                RangeInclusive::new(
-                    if_expr.clone().syntax().clone().into(),
-                    if_expr.syntax().clone().into(),
-                ),
-                &mut then_statements,
-            )
-        }
-    })
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs
new file mode 100644
index 000000000..2b8e273b3
--- /dev/null
+++ b/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -0,0 +1,321 @@
+use hir::{EnumVariant, Module, ModuleDef, Name};
+use ra_db::FileId;
+use ra_fmt::leading_indent;
+use ra_ide_db::{defs::Definition, search::Reference, RootDatabase};
+use ra_syntax::{
+    algo::find_node_at_offset,
+    ast::{self, ArgListOwner, AstNode, NameOwner, VisibilityOwner},
+    SourceFile, SyntaxNode, TextRange, TextSize,
+};
+use rustc_hash::FxHashSet;
+
+use crate::{
+    assist_context::AssistBuilder, utils::insert_use_statement, AssistContext, AssistId,
+    AssistKind, Assists,
+};
+
+// Assist: extract_struct_from_enum_variant
+//
+// Extracts a struct from enum variant.
+//
+// ```
+// enum A { <|>One(u32, u32) }
+// ```
+// ->
+// ```
+// struct One(pub u32, pub u32);
+//
+// enum A { One(One) }
+// ```
+pub(crate) fn extract_struct_from_enum_variant(
+    acc: &mut Assists,
+    ctx: &AssistContext,
+) -> Option<()> {
+    let variant = ctx.find_node_at_offset::<ast::EnumVariant>()?;
+    let field_list = match variant.kind() {
+        ast::StructKind::Tuple(field_list) => field_list,
+        _ => return None,
+    };
+    let variant_name = variant.name()?.to_string();
+    let variant_hir = ctx.sema.to_def(&variant)?;
+    if existing_struct_def(ctx.db(), &variant_name, &variant_hir) {
+        return None;
+    }
+    let enum_ast = variant.parent_enum();
+    let visibility = enum_ast.visibility();
+    let enum_hir = ctx.sema.to_def(&enum_ast)?;
+    let variant_hir_name = variant_hir.name(ctx.db());
+    let enum_module_def = ModuleDef::from(enum_hir);
+    let current_module = enum_hir.module(ctx.db());
+    let target = variant.syntax().text_range();
+    acc.add(
+        AssistId("extract_struct_from_enum_variant", AssistKind::RefactorRewrite),
+        "Extract struct from enum variant",
+        target,
+        |builder| {
+            let definition = Definition::ModuleDef(ModuleDef::EnumVariant(variant_hir));
+            let res = definition.find_usages(&ctx.sema, None);
+            let start_offset = variant.parent_enum().syntax().text_range().start();
+            let mut visited_modules_set = FxHashSet::default();
+            visited_modules_set.insert(current_module);
+            for reference in res {
+                let source_file = ctx.sema.parse(reference.file_range.file_id);
+                update_reference(
+                    ctx,
+                    builder,
+                    reference,
+                    &source_file,
+                    &enum_module_def,
+                    &variant_hir_name,
+                    &mut visited_modules_set,
+                );
+            }
+            extract_struct_def(
+                builder,
+                enum_ast.syntax(),
+                &variant_name,
+                &field_list.to_string(),
+                start_offset,
+                ctx.frange.file_id,
+                &visibility,
+            );
+            let list_range = field_list.syntax().text_range();
+            update_variant(builder, &variant_name, ctx.frange.file_id, list_range);
+        },
+    )
+}
+
+fn existing_struct_def(db: &RootDatabase, variant_name: &str, variant: &EnumVariant) -> bool {
+    variant
+        .parent_enum(db)
+        .module(db)
+        .scope(db, None)
+        .into_iter()
+        .any(|(name, _)| name.to_string() == variant_name.to_string())
+}
+
+fn insert_import(
+    ctx: &AssistContext,
+    builder: &mut AssistBuilder,
+    path: &ast::PathExpr,
+    module: &Module,
+    enum_module_def: &ModuleDef,
+    variant_hir_name: &Name,
+) -> Option<()> {
+    let db = ctx.db();
+    let mod_path = module.find_use_path(db, enum_module_def.clone());
+    if let Some(mut mod_path) = mod_path {
+        mod_path.segments.pop();
+        mod_path.segments.push(variant_hir_name.clone());
+        insert_use_statement(path.syntax(), &mod_path, ctx, builder.text_edit_builder());
+    }
+    Some(())
+}
+
+fn extract_struct_def(
+    builder: &mut AssistBuilder,
+    enum_ast: &SyntaxNode,
+    variant_name: &str,
+    variant_list: &str,
+    start_offset: TextSize,
+    file_id: FileId,
+    visibility: &Option<ast::Visibility>,
+) -> Option<()> {
+    let visibility_string = if let Some(visibility) = visibility {
+        format!("{} ", visibility.to_string())
+    } else {
+        "".to_string()
+    };
+    let indent = if let Some(indent) = leading_indent(enum_ast) {
+        indent.to_string()
+    } else {
+        "".to_string()
+    };
+    let struct_def = format!(
+        r#"{}struct {}{};
+
+{}"#,
+        visibility_string,
+        variant_name,
+        list_with_visibility(variant_list),
+        indent
+    );
+    builder.edit_file(file_id);
+    builder.insert(start_offset, struct_def);
+    Some(())
+}
+
+fn update_variant(
+    builder: &mut AssistBuilder,
+    variant_name: &str,
+    file_id: FileId,
+    list_range: TextRange,
+) -> Option<()> {
+    let inside_variant_range = TextRange::new(
+        list_range.start().checked_add(TextSize::from(1))?,
+        list_range.end().checked_sub(TextSize::from(1))?,
+    );
+    builder.edit_file(file_id);
+    builder.replace(inside_variant_range, variant_name);
+    Some(())
+}
+
+fn update_reference(
+    ctx: &AssistContext,
+    builder: &mut AssistBuilder,
+    reference: Reference,
+    source_file: &SourceFile,
+    enum_module_def: &ModuleDef,
+    variant_hir_name: &Name,
+    visited_modules_set: &mut FxHashSet<Module>,
+) -> Option<()> {
+    let path_expr: ast::PathExpr = find_node_at_offset::<ast::PathExpr>(
+        source_file.syntax(),
+        reference.file_range.range.start(),
+    )?;
+    let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?;
+    let list = call.arg_list()?;
+    let segment = path_expr.path()?.segment()?;
+    let module = ctx.sema.scope(&path_expr.syntax()).module()?;
+    let list_range = list.syntax().text_range();
+    let inside_list_range = TextRange::new(
+        list_range.start().checked_add(TextSize::from(1))?,
+        list_range.end().checked_sub(TextSize::from(1))?,
+    );
+    builder.edit_file(reference.file_range.file_id);
+    if !visited_modules_set.contains(&module) {
+        if insert_import(ctx, builder, &path_expr, &module, enum_module_def, variant_hir_name)
+            .is_some()
+        {
+            visited_modules_set.insert(module);
+        }
+    }
+    builder.replace(inside_list_range, format!("{}{}", segment, list));
+    Some(())
+}
+
+fn list_with_visibility(list: &str) -> String {
+    list.split(',')
+        .map(|part| {
+            let index = if part.chars().next().unwrap() == '(' { 1usize } else { 0 };
+            let mut mod_part = part.trim().to_string();
+            mod_part.insert_str(index, "pub ");
+            mod_part
+        })
+        .collect::<Vec<String>>()
+        .join(", ")
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::{
+        tests::{check_assist, check_assist_not_applicable},
+        utils::FamousDefs,
+    };
+
+    use super::*;
+
+    #[test]
+    fn test_extract_struct_several_fields() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { <|>One(u32, u32) }",
+            r#"struct One(pub u32, pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_one_field() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { <|>One(u32) }",
+            r#"struct One(pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_pub_visibility() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "pub enum A { <|>One(u32, u32) }",
+            r#"pub struct One(pub u32, pub u32);
+
+pub enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_with_complex_imports() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"mod my_mod {
+    fn another_fn() {
+        let m = my_other_mod::MyEnum::MyField(1, 1);
+    }
+
+    pub mod my_other_mod {
+        fn another_fn() {
+            let m = MyEnum::MyField(1, 1);
+        }
+
+        pub enum MyEnum {
+            <|>MyField(u8, u8),
+        }
+    }
+}
+
+fn another_fn() {
+    let m = my_mod::my_other_mod::MyEnum::MyField(1, 1);
+}"#,
+            r#"use my_mod::my_other_mod::MyField;
+
+mod my_mod {
+    use my_other_mod::MyField;
+
+    fn another_fn() {
+        let m = my_other_mod::MyEnum::MyField(MyField(1, 1));
+    }
+
+    pub mod my_other_mod {
+        fn another_fn() {
+            let m = MyEnum::MyField(MyField(1, 1));
+        }
+
+        pub struct MyField(pub u8, pub u8);
+
+        pub enum MyEnum {
+            MyField(MyField),
+        }
+    }
+}
+
+fn another_fn() {
+    let m = my_mod::my_other_mod::MyEnum::MyField(MyField(1, 1));
+}"#,
+        );
+    }
+
+    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(extract_struct_from_enum_variant, &fixture)
+    }
+
+    #[test]
+    fn test_extract_enum_not_applicable_for_element_with_no_fields() {
+        check_not_applicable("enum A { <|>One }");
+    }
+
+    #[test]
+    fn test_extract_enum_not_applicable_if_struct_exists() {
+        check_not_applicable(
+            r#"struct One;
+        enum A { <|>One(u8) }"#,
+        );
+    }
+}
diff --git a/crates/ra_assists/src/handlers/introduce_variable.rs b/crates/ra_assists/src/handlers/extract_variable.rs
index 31d6539f7..481baf1a4 100644
--- a/crates/ra_assists/src/handlers/introduce_variable.rs
+++ b/crates/ra_assists/src/handlers/extract_variable.rs
@@ -9,9 +9,9 @@ use ra_syntax::{
 use stdx::format_to;
 use test_utils::mark;
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
-// Assist: introduce_variable
+// Assist: extract_variable
 //
 // Extracts subexpression into a variable.
 //
@@ -27,13 +27,13 @@ use crate::{AssistContext, AssistId, Assists};
 //     var_name * 4;
 // }
 // ```
-pub(crate) fn introduce_variable(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn extract_variable(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     if ctx.frange.range.is_empty() {
         return None;
     }
     let node = ctx.covering_element();
     if node.kind() == COMMENT {
-        mark::hit!(introduce_var_in_comment_is_not_applicable);
+        mark::hit!(extract_var_in_comment_is_not_applicable);
         return None;
     }
     let expr = node.ancestors().find_map(valid_target_expr)?;
@@ -43,65 +43,85 @@ pub(crate) fn introduce_variable(acc: &mut Assists, ctx: &AssistContext) -> Opti
         return None;
     }
     let target = expr.syntax().text_range();
-    acc.add(AssistId("introduce_variable"), "Extract into variable", target, move |edit| {
-        let mut buf = String::new();
-
-        if wrap_in_block {
-            buf.push_str("{ let var_name = ");
-        } else {
-            buf.push_str("let var_name = ");
-        };
-        format_to!(buf, "{}", expr.syntax());
-
-        let full_stmt = ast::ExprStmt::cast(anchor_stmt.clone());
-        let is_full_stmt = if let Some(expr_stmt) = &full_stmt {
-            Some(expr.syntax().clone()) == expr_stmt.expr().map(|e| e.syntax().clone())
-        } else {
-            false
-        };
-        if is_full_stmt {
-            mark::hit!(test_introduce_var_expr_stmt);
-            if full_stmt.unwrap().semicolon_token().is_none() {
-                buf.push_str(";");
+    acc.add(
+        AssistId("extract_variable", AssistKind::RefactorExtract),
+        "Extract into variable",
+        target,
+        move |edit| {
+            let field_shorthand = match expr.syntax().parent().and_then(ast::RecordField::cast) {
+                Some(field) => field.name_ref(),
+                None => None,
+            };
+
+            let mut buf = String::new();
+
+            let var_name = match &field_shorthand {
+                Some(it) => it.to_string(),
+                None => "var_name".to_string(),
+            };
+            let expr_range = match &field_shorthand {
+                Some(it) => it.syntax().text_range().cover(expr.syntax().text_range()),
+                None => expr.syntax().text_range(),
+            };
+
+            if wrap_in_block {
+                format_to!(buf, "{{ let {} = ", var_name);
+            } else {
+                format_to!(buf, "let {} = ", var_name);
+            };
+            format_to!(buf, "{}", expr.syntax());
+
+            let full_stmt = ast::ExprStmt::cast(anchor_stmt.clone());
+            let is_full_stmt = if let Some(expr_stmt) = &full_stmt {
+                Some(expr.syntax().clone()) == expr_stmt.expr().map(|e| e.syntax().clone())
+            } else {
+                false
+            };
+            if is_full_stmt {
+                mark::hit!(test_extract_var_expr_stmt);
+                if full_stmt.unwrap().semicolon_token().is_none() {
+                    buf.push_str(";");
+                }
+                match ctx.config.snippet_cap {
+                    Some(cap) => {
+                        let snip = buf
+                            .replace(&format!("let {}", var_name), &format!("let $0{}", var_name));
+                        edit.replace_snippet(cap, expr_range, snip)
+                    }
+                    None => edit.replace(expr_range, buf),
+                }
+                return;
+            }
+
+            buf.push_str(";");
+
+            // We want to maintain the indent level,
+            // but we do not want to duplicate possible
+            // extra newlines in the indent block
+            let text = indent.text();
+            if text.starts_with('\n') {
+                buf.push_str("\n");
+                buf.push_str(text.trim_start_matches('\n'));
+            } else {
+                buf.push_str(text);
             }
-            let offset = expr.syntax().text_range();
+
+            edit.replace(expr_range, var_name.clone());
+            let offset = anchor_stmt.text_range().start();
             match ctx.config.snippet_cap {
                 Some(cap) => {
-                    let snip = buf.replace("let var_name", "let $0var_name");
-                    edit.replace_snippet(cap, offset, snip)
+                    let snip =
+                        buf.replace(&format!("let {}", var_name), &format!("let $0{}", var_name));
+                    edit.insert_snippet(cap, offset, snip)
                 }
-                None => edit.replace(offset, buf),
+                None => edit.insert(offset, buf),
             }
-            return;
-        }
 
-        buf.push_str(";");
-
-        // We want to maintain the indent level,
-        // but we do not want to duplicate possible
-        // extra newlines in the indent block
-        let text = indent.text();
-        if text.starts_with('\n') {
-            buf.push_str("\n");
-            buf.push_str(text.trim_start_matches('\n'));
-        } else {
-            buf.push_str(text);
-        }
-
-        edit.replace(expr.syntax().text_range(), "var_name".to_string());
-        let offset = anchor_stmt.text_range().start();
-        match ctx.config.snippet_cap {
-            Some(cap) => {
-                let snip = buf.replace("let var_name", "let $0var_name");
-                edit.insert_snippet(cap, offset, snip)
+            if wrap_in_block {
+                edit.insert(anchor_stmt.text_range().end(), " }");
             }
-            None => edit.insert(offset, buf),
-        }
-
-        if wrap_in_block {
-            edit.insert(anchor_stmt.text_range().end(), " }");
-        }
-    })
+        },
+    )
 }
 
 /// Check whether the node is a valid expression which can be extracted to a variable.
@@ -118,7 +138,7 @@ fn valid_target_expr(node: SyntaxNode) -> Option<ast::Expr> {
     }
 }
 
-/// Returns the syntax node which will follow the freshly introduced var
+/// Returns the syntax node which will follow the freshly extractd var
 /// and a boolean indicating whether we have to wrap it within a { } block
 /// to produce correct code.
 /// It can be a statement, the last in a block expression or a wanna be block
@@ -127,7 +147,7 @@ fn anchor_stmt(expr: ast::Expr) -> Option<(SyntaxNode, bool)> {
     expr.syntax().ancestors().find_map(|node| {
         if let Some(expr) = node.parent().and_then(ast::BlockExpr::cast).and_then(|it| it.expr()) {
             if expr.syntax() == &node {
-                mark::hit!(test_introduce_var_last_expr);
+                mark::hit!(test_extract_var_last_expr);
                 return Some((node, false));
             }
         }
@@ -155,9 +175,9 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_introduce_var_simple() {
+    fn test_extract_var_simple() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             r#"
 fn foo() {
     foo(<|>1 + 1<|>);
@@ -171,16 +191,16 @@ fn foo() {
     }
 
     #[test]
-    fn introduce_var_in_comment_is_not_applicable() {
-        mark::check!(introduce_var_in_comment_is_not_applicable);
-        check_assist_not_applicable(introduce_variable, "fn main() { 1 + /* <|>comment<|> */ 1; }");
+    fn extract_var_in_comment_is_not_applicable() {
+        mark::check!(extract_var_in_comment_is_not_applicable);
+        check_assist_not_applicable(extract_variable, "fn main() { 1 + /* <|>comment<|> */ 1; }");
     }
 
     #[test]
-    fn test_introduce_var_expr_stmt() {
-        mark::check!(test_introduce_var_expr_stmt);
+    fn test_extract_var_expr_stmt() {
+        mark::check!(test_extract_var_expr_stmt);
         check_assist(
-            introduce_variable,
+            extract_variable,
             r#"
 fn foo() {
     <|>1 + 1<|>;
@@ -191,7 +211,7 @@ fn foo() {
 }"#,
         );
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() {
     <|>{ let x = 0; x }<|>
@@ -206,9 +226,9 @@ fn foo() {
     }
 
     #[test]
-    fn test_introduce_var_part_of_expr_stmt() {
+    fn test_extract_var_part_of_expr_stmt() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() {
     <|>1<|> + 1;
@@ -222,38 +242,42 @@ fn foo() {
     }
 
     #[test]
-    fn test_introduce_var_last_expr() {
-        mark::check!(test_introduce_var_last_expr);
+    fn test_extract_var_last_expr() {
+        mark::check!(test_extract_var_last_expr);
         check_assist(
-            introduce_variable,
-            "
+            extract_variable,
+            r#"
 fn foo() {
     bar(<|>1 + 1<|>)
-}",
-            "
+}
+"#,
+            r#"
 fn foo() {
     let $0var_name = 1 + 1;
     bar(var_name)
-}",
+}
+"#,
         );
         check_assist(
-            introduce_variable,
-            "
+            extract_variable,
+            r#"
 fn foo() {
     <|>bar(1 + 1)<|>
-}",
-            "
+}
+"#,
+            r#"
 fn foo() {
     let $0var_name = bar(1 + 1);
     var_name
-}",
+}
+"#,
         )
     }
 
     #[test]
-    fn test_introduce_var_in_match_arm_no_block() {
+    fn test_extract_var_in_match_arm_no_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let x = true;
@@ -276,9 +300,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_in_match_arm_with_block() {
+    fn test_extract_var_in_match_arm_with_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let x = true;
@@ -308,9 +332,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_in_closure_no_block() {
+    fn test_extract_var_in_closure_no_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let lambda = |x: u32| <|>x * 2<|>;
@@ -325,9 +349,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_in_closure_with_block() {
+    fn test_extract_var_in_closure_with_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let lambda = |x: u32| { <|>x * 2<|> };
@@ -342,9 +366,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_path_simple() {
+    fn test_extract_var_path_simple() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let o = <|>Some(true)<|>;
@@ -360,9 +384,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_path_method() {
+    fn test_extract_var_path_method() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let v = <|>bar.foo()<|>;
@@ -378,9 +402,9 @@ fn main() {
     }