Support .editorconfig (#19455)

Closes https://github.com/zed-industries/zed/issues/8534
Supersedes https://github.com/zed-industries/zed/pull/16349

Potential concerns:
* we do not follow up to the `/` when looking for `.editorconfig`, only
up to the worktree root.
Seems fine for most of the cases, and the rest should be solved
generically later, as the same issue exists for settings.json
* `fn language` in `AllLanguageSettings` is very hot, called very
frequently during rendering. We accumulate and parse all `.editorconfig`
file contents beforehand, but have to go over globs and match these
against the path given + merge the properties still.
This does not seem to be very bad, but needs more testing and
potentially some extra caching.


Release Notes:

- Added .editorconfig support

---------

Co-authored-by: Ulysse Buonomo <buonomo.ulysse@gmail.com>

crates/collab/src/rpc.rs

@@ -2237,7 +2237,7 @@ fn join_project_internal(
                     worktree_id: worktree.id,
                     path: settings_file.path,
                     content: Some(settings_file.content),
-                    kind: Some(proto::update_user_settings::Kind::Settings.into()),
+                    kind: Some(settings_file.kind.to_proto() as i32),
                 },
             )?;
         }

crates/collab/src/tests/editor_tests.rs

@@ -12,6 +12,7 @@ use editor::{
     test::editor_test_context::{AssertionContextManager, EditorTestContext},
     Editor,
 };
+use fs::Fs;
 use futures::StreamExt;
 use gpui::{TestAppContext, UpdateGlobal, VisualContext, VisualTestContext};
 use indoc::indoc;
@@ -30,7 +31,7 @@ use serde_json::json;
 use settings::SettingsStore;
 use std::{
     ops::Range,
-    path::Path,
+    path::{Path, PathBuf},
     sync::{
         atomic::{self, AtomicBool, AtomicUsize},
         Arc,
@@ -60,7 +61,7 @@ async fn test_host_disconnect(
         .fs()
         .insert_tree(
             "/a",
-            serde_json::json!({
+            json!({
                 "a.txt": "a-contents",
                 "b.txt": "b-contents",
             }),
@@ -2152,6 +2153,295 @@ async fn test_git_blame_is_forwarded(cx_a: &mut TestAppContext, cx_b: &mut TestA
     });
 }
 
+#[gpui::test(iterations = 30)]
+async fn test_collaborating_with_editorconfig(
+    cx_a: &mut TestAppContext,
+    cx_b: &mut TestAppContext,
+) {
+    let mut server = TestServer::start(cx_a.executor()).await;
+    let client_a = server.create_client(cx_a, "user_a").await;
+    let client_b = server.create_client(cx_b, "user_b").await;
+    server
+        .create_room(&mut [(&client_a, cx_a), (&client_b, cx_b)])
+        .await;
+    let active_call_a = cx_a.read(ActiveCall::global);
+
+    cx_b.update(editor::init);
+
+    // Set up a fake language server.
+    client_a.language_registry().add(rust_lang());
+    client_a
+        .fs()
+        .insert_tree(
+            "/a",
+            json!({
+                "src": {
+                    "main.rs": "mod other;\nfn main() { let foo = other::foo(); }",
+                    "other_mod": {
+                        "other.rs": "pub fn foo() -> usize {\n    4\n}",
+                        ".editorconfig": "",
+                    },
+                },
+                ".editorconfig": "[*]\ntab_width = 2\n",
+            }),
+        )
+        .await;
+    let (project_a, worktree_id) = client_a.build_local_project("/a", cx_a).await;
+    let project_id = active_call_a
+        .update(cx_a, |call, cx| call.share_project(project_a.clone(), cx))
+        .await
+        .unwrap();
+    let main_buffer_a = project_a
+        .update(cx_a, |p, cx| {
+            p.open_buffer((worktree_id, "src/main.rs"), cx)
+        })
+        .await
+        .unwrap();
+    let other_buffer_a = project_a
+        .update(cx_a, |p, cx| {
+            p.open_buffer((worktree_id, "src/other_mod/other.rs"), cx)
+        })
+        .await
+        .unwrap();
+    let cx_a = cx_a.add_empty_window();
+    let main_editor_a =
+        cx_a.new_view(|cx| Editor::for_buffer(main_buffer_a, Some(project_a.clone()), cx));
+    let other_editor_a =
+        cx_a.new_view(|cx| Editor::for_buffer(other_buffer_a, Some(project_a), cx));
+    let mut main_editor_cx_a = EditorTestContext {
+        cx: cx_a.clone(),
+        window: cx_a.handle(),
+        editor: main_editor_a,
+        assertion_cx: AssertionContextManager::new(),
+    };
+    let mut other_editor_cx_a = EditorTestContext {
+        cx: cx_a.clone(),
+        window: cx_a.handle(),
+        editor: other_editor_a,
+        assertion_cx: AssertionContextManager::new(),
+    };
+
+    // Join the project as client B.
+    let project_b = client_b.join_remote_project(project_id, cx_b).await;
+    let main_buffer_b = project_b
+        .update(cx_b, |p, cx| {
+            p.open_buffer((worktree_id, "src/main.rs"), cx)
+        })
+        .await
+        .unwrap();
+    let other_buffer_b = project_b
+        .update(cx_b, |p, cx| {
+            p.open_buffer((worktree_id, "src/other_mod/other.rs"), cx)
+        })
+        .await
+        .unwrap();
+    let cx_b = cx_b.add_empty_window();
+    let main_editor_b =
+        cx_b.new_view(|cx| Editor::for_buffer(main_buffer_b, Some(project_b.clone()), cx));
+    let other_editor_b =
+        cx_b.new_view(|cx| Editor::for_buffer(other_buffer_b, Some(project_b.clone()), cx));
+    let mut main_editor_cx_b = EditorTestContext {
+        cx: cx_b.clone(),
+        window: cx_b.handle(),
+        editor: main_editor_b,
+        assertion_cx: AssertionContextManager::new(),
+    };
+    let mut other_editor_cx_b = EditorTestContext {
+        cx: cx_b.clone(),
+        window: cx_b.handle(),
+        editor: other_editor_b,
+        assertion_cx: AssertionContextManager::new(),
+    };
+
+    let initial_main = indoc! {"
+ˇmod other;
+fn main() { let foo = other::foo(); }"};
+    let initial_other = indoc! {"
+ˇpub fn foo() -> usize {
+    4
+}"};
+
+    let first_tabbed_main = indoc! {"
+  ˇmod other;
+fn main() { let foo = other::foo(); }"};
+    tab_undo_assert(
+        &mut main_editor_cx_a,
+        &mut main_editor_cx_b,
+        initial_main,
+        first_tabbed_main,
+        true,
+    );
+    tab_undo_assert(
+        &mut main_editor_cx_a,
+        &mut main_editor_cx_b,
+        initial_main,
+        first_tabbed_main,
+        false,
+    );
+
+    let first_tabbed_other = indoc! {"
+  ˇpub fn foo() -> usize {
+    4
+}"};
+    tab_undo_assert(
+        &mut other_editor_cx_a,
+        &mut other_editor_cx_b,
+        initial_other,
+        first_tabbed_other,
+        true,
+    );
+    tab_undo_assert(
+        &mut other_editor_cx_a,
+        &mut other_editor_cx_b,
+        initial_other,
+        first_tabbed_other,
+        false,
+    );
+
+    client_a
+        .fs()
+        .atomic_write(
+            PathBuf::from("/a/src/.editorconfig"),
+            "[*]\ntab_width = 3\n".to_owned(),
+        )
+        .await
+        .unwrap();
+    cx_a.run_until_parked();
+    cx_b.run_until_parked();
+
+    let second_tabbed_main = indoc! {"
+   ˇmod other;
+fn main() { let foo = other::foo(); }"};
+    tab_undo_assert(
+        &mut main_editor_cx_a,
+        &mut main_editor_cx_b,
+        initial_main,
+        second_tabbed_main,
+        true,
+    );
+    tab_undo_assert(
+        &mut main_editor_cx_a,
+        &mut main_editor_cx_b,
+        initial_main,
+        second_tabbed_main,
+        false,
+    );
+
+    let second_tabbed_other = indoc! {"
+   ˇpub fn foo() -> usize {
+    4
+}"};
+    tab_undo_assert(
+        &mut other_editor_cx_a,
+        &mut other_editor_cx_b,
+        initial_other,
+        second_tabbed_other,
+        true,
+    );
+    tab_undo_assert(
+        &mut other_editor_cx_a,
+        &mut other_editor_cx_b,
+        initial_other,
+        second_tabbed_other,
+        false,
+    );
+
+    let editorconfig_buffer_b = project_b
+        .update(cx_b, |p, cx| {
+            p.open_buffer((worktree_id, "src/other_mod/.editorconfig"), cx)
+        })
+        .await
+        .unwrap();
+    editorconfig_buffer_b.update(cx_b, |buffer, cx| {
+        buffer.set_text("[*.rs]\ntab_width = 6\n", cx);
+    });
+    project_b
+        .update(cx_b, |project, cx| {
+            project.save_buffer(editorconfig_buffer_b.clone(), cx)
+        })
+        .await
+        .unwrap();
+    cx_a.run_until_parked();
+    cx_b.run_until_parked();
+
+    tab_undo_assert(
+        &mut main_editor_cx_a,
+        &mut main_editor_cx_b,
+        initial_main,
+        second_tabbed_main,
+        true,
+    );
+    tab_undo_assert(
+        &mut main_editor_cx_a,
+        &mut main_editor_cx_b,
+        initial_main,
+        second_tabbed_main,
+        false,
+    );
+
+    let third_tabbed_other = indoc! {"
+      ˇpub fn foo() -> usize {
+    4
+}"};
+    tab_undo_assert(
+        &mut other_editor_cx_a,
+        &mut other_editor_cx_b,
+        initial_other,
+        third_tabbed_other,
+        true,
+    );
+
+    tab_undo_assert(
+        &mut other_editor_cx_a,
+        &mut other_editor_cx_b,
+        initial_other,
+        third_tabbed_other,
+        false,
+    );
+}
+
+#[track_caller]
+fn tab_undo_assert(
+    cx_a: &mut EditorTestContext,
+    cx_b: &mut EditorTestContext,
+    expected_initial: &str,
+    expected_tabbed: &str,
+    a_tabs: bool,
+) {
+    cx_a.assert_editor_state(expected_initial);
+    cx_b.assert_editor_state(expected_initial);
+
+    if a_tabs {
+        cx_a.update_editor(|editor, cx| {
+            editor.tab(&editor::actions::Tab, cx);
+        });
+    } else {
+        cx_b.update_editor(|editor, cx| {
+            editor.tab(&editor::actions::Tab, cx);
+        });
+    }
+
+    cx_a.run_until_parked();
+    cx_b.run_until_parked();
+
+    cx_a.assert_editor_state(expected_tabbed);
+    cx_b.assert_editor_state(expected_tabbed);
+
+    if a_tabs {
+        cx_a.update_editor(|editor, cx| {
+            editor.undo(&editor::actions::Undo, cx);
+        });
+    } else {
+        cx_b.update_editor(|editor, cx| {
+            editor.undo(&editor::actions::Undo, cx);
+        });
+    }
+    cx_a.run_until_parked();
+    cx_b.run_until_parked();
+    cx_a.assert_editor_state(expected_initial);
+    cx_b.assert_editor_state(expected_initial);
+}
+
 fn extract_hint_labels(editor: &Editor) -> Vec<String> {
     let mut labels = Vec::new();
     for hint in editor.inlay_hint_cache().hints() {

crates/collab/src/tests/integration_tests.rs

@@ -34,7 +34,7 @@ use project::{
 };
 use rand::prelude::*;
 use serde_json::json;
-use settings::{LocalSettingsKind, SettingsStore};
+use settings::SettingsStore;
 use std::{
     cell::{Cell, RefCell},
     env, future, mem,
@@ -3328,16 +3328,8 @@ async fn test_local_settings(
                 .local_settings(worktree_b.read(cx).id())
                 .collect::<Vec<_>>(),
             &[
-                (
-                    Path::new("").into(),
-                    LocalSettingsKind::Settings,
-                    r#"{"tab_size":2}"#.to_string()
-                ),
-                (
-                    Path::new("a").into(),
-                    LocalSettingsKind::Settings,
-                    r#"{"tab_size":8}"#.to_string()
-                ),
+                (Path::new("").into(), r#"{"tab_size":2}"#.to_string()),
+                (Path::new("a").into(), r#"{"tab_size":8}"#.to_string()),
             ]
         )
     });
@@ -3355,16 +3347,8 @@ async fn test_local_settings(
                 .local_settings(worktree_b.read(cx).id())
                 .collect::<Vec<_>>(),
             &[
-                (
-                    Path::new("").into(),
-                    LocalSettingsKind::Settings,
-                    r#"{}"#.to_string()
-                ),
-                (
-                    Path::new("a").into(),
-                    LocalSettingsKind::Settings,
-                    r#"{"tab_size":8}"#.to_string()
-                ),
+                (Path::new("").into(), r#"{}"#.to_string()),
+                (Path::new("a").into(), r#"{"tab_size":8}"#.to_string()),
             ]
         )
     });
@@ -3392,16 +3376,8 @@ async fn test_local_settings(
                 .local_settings(worktree_b.read(cx).id())
                 .collect::<Vec<_>>(),
             &[
-                (
-                    Path::new("a").into(),
-                    LocalSettingsKind::Settings,
-                    r#"{"tab_size":8}"#.to_string()
-                ),
-                (
-                    Path::new("b").into(),
-                    LocalSettingsKind::Settings,
-                    r#"{"tab_size":4}"#.to_string()
-                ),
+                (Path::new("a").into(), r#"{"tab_size":8}"#.to_string()),
+                (Path::new("b").into(), r#"{"tab_size":4}"#.to_string()),
             ]
         )
     });
@@ -3431,11 +3407,7 @@ async fn test_local_settings(
             store
                 .local_settings(worktree_b.read(cx).id())
                 .collect::<Vec<_>>(),
-            &[(
-                Path::new("a").into(),
-                LocalSettingsKind::Settings,
-                r#"{"hard_tabs":true}"#.to_string()
-            ),]
+            &[(Path::new("a").into(), r#"{"hard_tabs":true}"#.to_string()),]
         )
     });
 }

crates/collab/src/tests/remote_editing_collaboration_tests.rs

@@ -3,7 +3,7 @@ use call::ActiveCall;
 use fs::{FakeFs, Fs as _};
 use gpui::{Context as _, TestAppContext};
 use http_client::BlockedHttpClient;
-use language::{language_settings::all_language_settings, LanguageRegistry};
+use language::{language_settings::language_settings, LanguageRegistry};
 use node_runtime::NodeRuntime;
 use project::ProjectPath;
 use remote::SshRemoteClient;
@@ -135,9 +135,7 @@ async fn test_sharing_an_ssh_remote_project(
     cx_b.read(|cx| {
         let file = buffer_b.read(cx).file();
         assert_eq!(
-            all_language_settings(file, cx)
-                .language(Some(&("Rust".into())))
-                .language_servers,
+            language_settings(Some("Rust".into()), file, cx).language_servers,
             ["override-rust-analyzer".to_string()]
         )
     });