16 files changed, 227 insertions, 61 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 320f70529..d470d84f2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,5 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-# asdasdasdasd
 [[package]]
 name = "addr2line"
 version = "0.13.0"
@@ -130,9 +129,9 @@ checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
 [[package]]
 name = "cargo_metadata"
-version = "0.11.3"
+version = "0.11.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e708746e51dfaeff27c6c3979a4005a7faddabe40144204a0b1ce5ad34a1d0a5"
+checksum = "a3a567c24b86754d629addc2db89e340ac9398d07b5875efcff837e3878e17ec"
 dependencies = [
  "semver",
  "serde",
@@ -251,6 +250,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "const_fn"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce90df4c658c62f12d78f7508cf92f9173e5184a539c10bfe54a3107b3ffd0f2"
+
+[[package]]
 name = "crc32fast"
 version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -265,18 +270,28 @@ version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b153fe7cbef478c567df0f972e02e6d736db11affe43dfc9c56a9374d1adfb87"
 dependencies = [
- "crossbeam-utils",
+ "crossbeam-utils 0.7.2",
  "maybe-uninit",
 ]
 
 [[package]]
+name = "crossbeam-channel"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dca26ee1f8d361640700bde38b2c37d8c22b3ce2d360e1fc1c74ea4b0aa7d775"
+dependencies = [
+ "cfg-if 1.0.0",
+ "crossbeam-utils 0.8.0",
+]
+
+[[package]]
 name = "crossbeam-deque"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f02af974daeee82218205558e51ec8768b48cf524bd01d550abe5573a608285"
 dependencies = [
  "crossbeam-epoch",
- "crossbeam-utils",
+ "crossbeam-utils 0.7.2",
  "maybe-uninit",
 ]
 
@@ -288,7 +303,7 @@ checksum = "058ed274caafc1f60c4997b5fc07bf7dc7cca454af7c6e81edffe5f33f70dace"
 dependencies = [
  "autocfg",
  "cfg-if 0.1.10",
- "crossbeam-utils",
+ "crossbeam-utils 0.7.2",
  "lazy_static",
  "maybe-uninit",
  "memoffset",
@@ -307,6 +322,18 @@ dependencies = [
 ]
 
 [[package]]
+name = "crossbeam-utils"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec91540d98355f690a86367e566ecad2e9e579f230230eb7c21398372be73ea5"
+dependencies = [
+ "autocfg",
+ "cfg-if 1.0.0",
+ "const_fn",
+ "lazy_static",
+]
+
+[[package]]
 name = "difference"
 version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -387,7 +414,7 @@ name = "flycheck"
 version = "0.0.0"
 dependencies = [
  "cargo_metadata",
- "crossbeam-channel",
+ "crossbeam-channel 0.5.0",
  "jod-thread",
  "log",
  "serde_json",
@@ -775,11 +802,11 @@ dependencies = [
 
 [[package]]
 name = "lsp-server"
-version = "0.3.4"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87fce8851309a325974ec76efe7c9d954d152c9ff4fded6520eb3c96d0aa3a96"
+checksum = "ff7452ee21b8de64f10ceb4e9fee1212e1a9579cd717226613333e751676c86a"
 dependencies = [
- "crossbeam-channel",
+ "crossbeam-channel 0.5.0",
  "log",
  "serde",
  "serde_json",
@@ -939,7 +966,7 @@ checksum = "77d03607cf88b4b160ba0e9ed425fff3cee3b55ac813f0c685b3a3772da37d0e"
 dependencies = [
  "anymap",
  "bitflags",
- "crossbeam-channel",
+ "crossbeam-channel 0.4.4",
  "filetime",
  "fsevent",
  "fsevent-sys",
@@ -1101,7 +1128,7 @@ dependencies = [
 name = "proc_macro_api"
 version = "0.0.0"
 dependencies = [
- "crossbeam-channel",
+ "crossbeam-channel 0.5.0",
  "jod-thread",
  "log",
  "serde",
@@ -1164,9 +1191,9 @@ dependencies = [
 
 [[package]]
 name = "pulldown-cmark"
-version = "0.7.2"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca36dea94d187597e104a5c8e4b07576a8a45aa5db48a65e12940d3eb7461f55"
+checksum = "ffade02495f22453cd593159ea2f59827aae7f53fa8323f756799b670881dcf8"
 dependencies = [
  "bitflags",
  "memchr",
@@ -1175,9 +1202,9 @@ dependencies = [
 
 [[package]]
 name = "pulldown-cmark-to-cmark"
-version = "5.0.0"
+version = "6.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32accf4473121d8c0b508ca5673363703762d6cc59cf25af1df48f653346f736"
+checksum = "e8f2b9878102358ec65434fdd1a9a161f8648bb2f531acc9260e4d094c96de23"
 dependencies = [
  "pulldown-cmark",
 ]
@@ -1209,9 +1236,9 @@ version = "1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e8c4fec834fb6e6d2dd5eece3c7b432a52f0ba887cf40e595190c4107edc08bf"
 dependencies = [
- "crossbeam-channel",
+ "crossbeam-channel 0.4.4",
  "crossbeam-deque",
- "crossbeam-utils",
+ "crossbeam-utils 0.7.2",
  "lazy_static",
  "num_cpus",
 ]
@@ -1224,9 +1251,9 @@ checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 
 [[package]]
 name = "regex"
-version = "1.3.9"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c3780fcf44b193bc4d09f36d2a3c87b251da4a046c87795a0d35f4f927ad8e6"
+checksum = "8963b85b8ce3074fecffde43b4b0dded83ce2f367dc8d363afc56679f3ee820b"
 dependencies = [
  "regex-syntax",
 ]
@@ -1243,9 +1270,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.18"
+version = "0.6.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26412eb97c6b088a6997e05f69403a802a92d520de2f8e63c2b65f9e0f47c4e8"
+checksum = "8cab7a364d15cde1e505267766a2d3c4e22a843e1a601f0fa7564c0f82ced11c"
 
 [[package]]
 name = "rowan"
@@ -1266,7 +1293,7 @@ dependencies = [
  "anyhow",
  "base_db",
  "cfg",
- "crossbeam-channel",
+ "crossbeam-channel 0.5.0",
  "env_logger",
  "expect-test",
  "flycheck",
@@ -1307,9 +1334,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_lexer"
-version = "682.0.0"
+version = "683.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5fea544ba13e72077e363981b0a4a87997b97f772b25a0aa7ec3df35a6adfe82"
+checksum = "c0c9a47e24d4b7d74ec583d8813803b36985ee082fe7debe55f257df92d5fe50"
 dependencies = [
  "unicode-xid",
 ]
@@ -1334,11 +1361,11 @@ checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
 
 [[package]]
 name = "salsa"
-version = "0.15.2"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ab29056d4fb4048a5f0d169c9b6e5526160c9ec37aded5a6879c2c9c445a8e4"
+checksum = "d8fadca2ab5de17acf66d744f4888049ca8f1bb9b8a1ab8afd9d032cc959c5dc"
 dependencies = [
- "crossbeam-utils",
+ "crossbeam-utils 0.8.0",
  "indexmap",
  "lock_api",
  "log",
@@ -1351,9 +1378,9 @@ dependencies = [
 
 [[package]]
 name = "salsa-macros"
-version = "0.15.2"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1c3aec007c63c4ed4cd7a018529fb0b5575c4562575fc6a40d6cd2ae0b792ef"
+checksum = "cd3904a4ba0a9d0211816177fd34b04c7095443f8cdacd11175064fe541c8fe2"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -1440,9 +1467,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.58"
+version = "1.0.59"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a230ea9107ca2220eea9d46de97eddcb04cd00e92d13dda78e478dd33fa82bd4"
+checksum = "dcac07dbffa1c65e7f816ab9eba78eb142c6d44410f4eeba1e26e4f5dfa56b95"
 dependencies = [
  "itoa",
  "ryu",
@@ -1807,7 +1834,7 @@ dependencies = [
 name = "vfs-notify"
 version = "0.0.0"
 dependencies = [
- "crossbeam-channel",
+ "crossbeam-channel 0.5.0",
  "jod-thread",
  "log",
  "notify",
diff --git a/bors.toml b/bors.toml
index 1f4eb510a..1f6603030 100644
--- a/bors.toml
+++ b/bors.toml
@@ -6,3 +6,4 @@ status = [
     "TypeScript (windows-latest)",
 ]
 delete_merged_branches = true
+timeout_sec = 1200 # 20 min
diff --git a/crates/assists/src/handlers/merge_imports.rs b/crates/assists/src/handlers/merge_imports.rs
index fe33cee53..fd9c9e03c 100644
--- a/crates/assists/src/handlers/merge_imports.rs
+++ b/crates/assists/src/handlers/merge_imports.rs
@@ -73,6 +73,20 @@ mod tests {
     use super::*;
 
     #[test]
+    fn test_merge_equal() {
+        check_assist(
+            merge_imports,
+            r"
+use std::fmt<|>::{Display, Debug};
+use std::fmt::{Display, Debug};
+",
+            r"
+use std::fmt::{Debug, Display};
+",
+        )
+    }
+
+    #[test]
     fn test_merge_first() {
         check_assist(
             merge_imports,
diff --git a/crates/assists/src/handlers/replace_qualified_name_with_use.rs b/crates/assists/src/handlers/replace_qualified_name_with_use.rs
index 74afc123b..c50bc7604 100644
--- a/crates/assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/assists/src/handlers/replace_qualified_name_with_use.rs
@@ -124,6 +124,23 @@ mod tests {
     use super::*;
 
     #[test]
+    fn test_replace_already_imported() {
+        check_assist(
+            replace_qualified_name_with_use,
+            r"use std::fs;
+
+fn main() {
+    std::f<|>s::Path
+}",
+            r"use std::fs;
+
+fn main() {
+    fs::Path
+}",
+        )
+    }
+
+    #[test]
     fn test_replace_add_use_no_anchor() {
         check_assist(
             replace_qualified_name_with_use,
@@ -393,7 +410,7 @@ impl std::fmt::Display<|> for Foo {
 }
 ",
             r"
-use std::fmt::{Display, nested::Debug};
+use std::fmt::{nested::Debug, Display};
 
 impl Display for Foo {
 }
diff --git a/crates/assists/src/utils/insert_use.rs b/crates/assists/src/utils/insert_use.rs
index f6025c99a..409985b3b 100644
--- a/crates/assists/src/utils/insert_use.rs
+++ b/crates/assists/src/utils/insert_use.rs
@@ -173,8 +173,15 @@ pub(crate) fn try_merge_trees(
     let rhs_path = rhs.path()?;
 
     let (lhs_prefix, rhs_prefix) = common_prefix(&lhs_path, &rhs_path)?;
-    let lhs = lhs.split_prefix(&lhs_prefix);
-    let rhs = rhs.split_prefix(&rhs_prefix);
+    let (lhs, rhs) = if is_simple_path(lhs)
+        && is_simple_path(rhs)
+        && lhs_path == lhs_prefix
+        && rhs_path == rhs_prefix
+    {
+        (lhs.clone(), rhs.clone())
+    } else {
+        (lhs.split_prefix(&lhs_prefix), rhs.split_prefix(&rhs_prefix))
+    };
     recursive_merge(&lhs, &rhs, merge)
 }
 
@@ -200,7 +207,18 @@ fn recursive_merge(
             return None;
         }
         let rhs_path = rhs_t.path();
-        match use_trees.binary_search_by(|p| path_cmp_bin_search(p.path(), rhs_path.clone())) {
+        match use_trees.binary_search_by(|lhs_t| {
+            let (lhs_t, rhs_t) = match lhs_t
+                .path()
+                .zip(rhs_path.clone())
+                .and_then(|(lhs, rhs)| common_prefix(&lhs, &rhs))
+            {
+                Some((lhs_p, rhs_p)) => (lhs_t.split_prefix(&lhs_p), rhs_t.split_prefix(&rhs_p)),
+                None => (lhs_t.clone(), rhs_t.clone()),
+            };
+
+            path_cmp_bin_search(lhs_t.path(), rhs_t.path())
+        }) {
             Ok(idx) => {
                 let lhs_t = &mut use_trees[idx];
                 let lhs_path = lhs_t.path()?;
@@ -239,6 +257,10 @@ fn recursive_merge(
                         use_trees.insert(idx, make::glob_use_tree());
                         continue;
                     }
+
+                    if lhs_t.use_tree_list().is_none() && rhs_t.use_tree_list().is_none() {
+                        continue;
+                    }
                 }
                 let lhs = lhs_t.split_prefix(&lhs_prefix);
                 let rhs = rhs_t.split_prefix(&rhs_prefix);
@@ -284,6 +306,10 @@ fn common_prefix(lhs: &ast::Path, rhs: &ast::Path) -> Option<(ast::Path, ast::Pa
     }
 }
 
+fn is_simple_path(use_tree: &ast::UseTree) -> bool {
+    use_tree.use_tree_list().is_none() && use_tree.star_token().is_none()
+}
+
 fn path_is_self(path: &ast::Path) -> bool {
     path.segment().and_then(|seg| seg.self_token()).is_some() && path.qualifier().is_none()
 }
@@ -327,11 +353,11 @@ fn path_cmp_for_sort(a: Option<ast::Path>, b: Option<ast::Path>) -> Ordering {
 
 /// Path comparison func for binary searching for merging.
 fn path_cmp_bin_search(lhs: Option<ast::Path>, rhs: Option<ast::Path>) -> Ordering {
-    match (lhs, rhs) {
+    match (lhs.and_then(|path| path.segment()), rhs.and_then(|path| path.segment())) {
         (None, None) => Ordering::Equal,
         (None, Some(_)) => Ordering::Less,
         (Some(_), None) => Ordering::Greater,
-        (Some(ref a), Some(ref b)) => path_cmp_short(a, b),
+        (Some(ref a), Some(ref b)) => path_segment_cmp(a, b),
     }
 }
 
@@ -513,6 +539,11 @@ mod tests {
     use test_utils::assert_eq_text;
 
     #[test]
+    fn insert_existing() {
+        check_full("std::fs", "use std::fs;", "use std::fs;")
+    }
+
+    #[test]
     fn insert_start() {
         check_none(
             "std::bar::AA",
@@ -802,6 +833,24 @@ use std::foo::bar::{Qux, quux::{Fez, Fizz}};",
     }
 
     #[test]
+    fn merge_groups_full_nested_long() {
+        check_full(
+            "std::foo::bar::Baz",
+            r"use std::{foo::bar::Qux};",
+            r"use std::{foo::bar::{Baz, Qux}};",
+        );
+    }
+
+    #[test]
+    fn merge_groups_last_nested_long() {
+        check_full(
+            "std::foo::bar::Baz",
+            r"use std::{foo::bar::Qux};",
+            r"use std::{foo::bar::{Baz, Qux}};",
+        );
+    }
+
+    #[test]
     fn merge_groups_skip_pub() {
         check_full(
             "std::io",
diff --git a/crates/base_db/Cargo.toml b/crates/base_db/Cargo.toml
index f7bfcb0d7..1724d2f85 100644
--- a/crates/base_db/Cargo.toml
+++ b/crates/base_db/Cargo.toml
@@ -10,7 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
-salsa = "0.15.2"
+salsa = "0.16.0"
 rustc-hash = "1.1.0"
 
 syntax = { path = "../syntax", version = "0.0.0" }
diff --git a/crates/flycheck/Cargo.toml b/crates/flycheck/Cargo.toml
index c230fc1e2..4e2b60b73 100644
--- a/crates/flycheck/Cargo.toml
+++ b/crates/flycheck/Cargo.toml
@@ -10,7 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
-crossbeam-channel = "0.4.0"
+crossbeam-channel = "0.5.0"
 log = "0.4.8"
 cargo_metadata = "0.11.1"
 serde_json = "1.0.48"
diff --git a/crates/ide/Cargo.toml b/crates/ide/Cargo.toml
index f0257403d..29dc9a6a8 100644
--- a/crates/ide/Cargo.toml
+++ b/crates/ide/Cargo.toml
@@ -16,8 +16,8 @@ itertools = "0.9.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 oorandom = "11.1.2"
-pulldown-cmark-to-cmark = "5.0.0"
-pulldown-cmark = {version = "0.7.2", default-features = false}
+pulldown-cmark-to-cmark = "6.0.0"
+pulldown-cmark = { version = "0.8.0", default-features = false }
 url = "2.1.1"
 
 stdx = { path = "../stdx", version = "0.0.0" }
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index 06af36b73..db3f911c8 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -1,9 +1,10 @@
 //! Resolves and rewrites links in markdown documentation.
 
+use std::convert::TryFrom;
 use std::iter::once;
 
 use itertools::Itertools;
-use pulldown_cmark::{CowStr, Event, LinkType, Options, Parser, Tag};
+use pulldown_cmark::{BrokenLink, CowStr, Event, InlineStr, LinkType, Options, Parser, Tag};
 use pulldown_cmark_to_cmark::{cmark_with_options, Options as CmarkOptions};
 use url::Url;
 
@@ -24,11 +25,13 @@ pub type DocumentationLink = String;
 
 /// Rewrite documentation links in markdown to point to an online host (e.g. docs.rs)
 pub fn rewrite_links(db: &RootDatabase, markdown: &str, definition: &Definition) -> String {
-    let doc = Parser::new_with_broken_link_callback(
-        markdown,
-        Options::empty(),
-        Some(&|label, _| Some((/*url*/ label.to_string(), /*title*/ label.to_string()))),
-    );
+    let mut cb = |link: BrokenLink| {
+        Some((
+            /*url*/ link.reference.to_owned().into(),
+            /*title*/ link.reference.to_owned().into(),
+        ))
+    };
+    let doc = Parser::new_with_broken_link_callback(markdown, Options::empty(), Some(&mut cb));
 
     let doc = map_links(doc, |target, title: &str| {
         // This check is imperfect, there's some overlap between valid intra-doc links
@@ -66,11 +69,11 @@ pub fn remove_links(markdown: &str) -> String {
     let mut opts = Options::empty();
     opts.insert(Options::ENABLE_FOOTNOTES);
 
-    let doc = Parser::new_with_broken_link_callback(
-        markdown,
-        opts,
-        Some(&|_, _| Some((String::new(), String::new()))),
-    );
+    let mut cb = |_: BrokenLink| {
+        let empty = InlineStr::try_from("").unwrap();
+        Some((CowStr::Inlined(empty.clone()), CowStr::Inlined(empty)))
+    };
+    let doc = Parser::new_with_broken_link_callback(markdown, opts, Some(&mut cb));
     let doc = doc.filter_map(move |evt| match evt {
         Event::Start(Tag::Link(link_type, ref target, ref title)) => {
             if link_type == LinkType::Inline && target.contains("://") {
diff --git a/crates/proc_macro_api/Cargo.toml b/crates/proc_macro_api/Cargo.toml
index 75f67a22e..3863e5189 100644
--- a/crates/proc_macro_api/Cargo.toml
+++ b/crates/proc_macro_api/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 log = "0.4.8"
-crossbeam-channel = "0.4.0"
+crossbeam-channel = "0.5.0"
 jod-thread = "0.1.1"
 
 tt = { path = "../tt", version = "0.0.0" }
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 631ffc4a7..df2ea6f85 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -16,7 +16,7 @@ path = "src/bin/main.rs"
 
 [dependencies]
 anyhow = "1.0.26"
-crossbeam-channel = "0.4.0"
+crossbeam-channel = "0.5.0"
 env_logger = { version = "0.7.1", default-features = false }
 itertools = "0.9.0"
 jod-thread = "0.1.0"
@@ -31,7 +31,7 @@ serde_json = "1.0.48"
 threadpool = "1.7.1"
 rayon = "1.3.1"
 mimalloc = { version = "0.1.19", default-features = false, optional = true }
-lsp-server = "0.3.3"
+lsp-server = "0.4.0"
 
 stdx = { path = "../stdx", version = "0.0.0" }
 flycheck = { path = "../flycheck", version = "0.0.0" }
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index 547fe9f47..c343f2f70 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.9.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "682.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "683.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"
diff --git a/crates/vfs-notify/Cargo.toml b/crates/vfs-notify/Cargo.toml
index 54b51faab..5b7c33b01 100644
--- a/crates/vfs-notify/Cargo.toml
+++ b/crates/vfs-notify/Cargo.toml
@@ -14,7 +14,7 @@ log = "0.4.8"
 rustc-hash = "1.0"
 jod-thread = "0.1.0"
 walkdir = "2.3.1"
-crossbeam-channel = "0.4.0"
+crossbeam-channel = "0.5.0"
 notify = "5.0.0-pre.3"
 
 vfs = { path = "../vfs", version = "0.0.0" }
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index 3f861f3e0..43a69d6ce 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -1,3 +1,13 @@
+<!---
+lsp_ext.rs hash: 286f8bbac885531a
+
+If you need to change the above hash to make the test pass, please check if you
+need to adjust this doc as well and ping this issue:
+
+  https://github.com/rust-analyzer/rust-analyzer/issues/4604
+
+--->
+
 # LSP Extensions
 
 This document describes LSP extensions used by rust-analyzer.
diff --git a/editors/code/src/commands.ts b/editors/code/src/commands.ts
index 1445e41d3..22509e874 100644
--- a/editors/code/src/commands.ts
+++ b/editors/code/src/commands.ts
@@ -442,8 +442,8 @@ export function openDocs(ctx: Ctx): Cmd {
 
 export function resolveCodeAction(ctx: Ctx): Cmd {
     const client = ctx.client;
-    return async () => {
-        const item: lc.WorkspaceEdit = await client.sendRequest(ra.resolveCodeAction, null);
+    return async (params: ra.ResolveCodeActionParams) => {
+        const item: lc.WorkspaceEdit = await client.sendRequest(ra.resolveCodeAction, params);
         if (!item) {
             return;
         }
diff --git a/xtask/tests/tidy.rs b/xtask/tests/tidy.rs
index 0c233f87d..b3bb9d543 100644
--- a/xtask/tests/tidy.rs
+++ b/xtask/tests/tidy.rs
@@ -45,6 +45,41 @@ fn smoke_test_docs_generation() {
 }
 
 #[test]
+fn check_lsp_extensions_docs() {
+    let expected_hash = {
+        let lsp_ext_rs =
+            fs2::read_to_string(project_root().join("crates/rust-analyzer/src/lsp_ext.rs"))
+                .unwrap();
+        stable_hash(lsp_ext_rs.as_str())
+    };
+
+    let actual_hash = {
+        let lsp_extensions_md =
+            fs2::read_to_string(project_root().join("docs/dev/lsp-extensions.md")).unwrap();
+        let text = lsp_extensions_md
+            .lines()
+            .find_map(|line| line.strip_prefix("lsp_ext.rs hash:"))
+            .unwrap()
+            .trim();
+        u64::from_str_radix(text, 16).unwrap()
+    };
+
+    if actual_hash != expected_hash {
+        panic!(
+            "
+lsp_ext.rs was changed without touching lsp-extensions.md.
+
+Expected hash: {:x}
+Actual hash:   {:x}
+
+Please adjust docs/dev/lsp-extensions.md.
+",
+            expected_hash, actual_hash
+        )
+    }
+}
+
+#[test]
 fn rust_files_are_tidy() {
     let mut tidy_docs = TidyDocs::default();
     for path in rust_files(&project_root().join("crates")) {
@@ -280,3 +315,13 @@ fn is_exclude_dir(p: &Path, dirs_to_exclude: &[&str]) -> bool {
         .filter_map(|it| it.as_os_str().to_str())
         .any(|it| dirs_to_exclude.contains(&it))
 }
+
+#[allow(deprecated)]
+fn stable_hash(text: &str) -> u64 {
+    use std::hash::{Hash, Hasher, SipHasher};
+
+    let text = text.replace('\r', "");
+    let mut hasher = SipHasher::default();
+    text.hash(&mut hasher);
+    hasher.finish()
+}