Add Code actions on save

.cargo/config.toml

@@ -14,4 +14,5 @@ rustflags = ["--cfg", "tokio_unstable", "-C", "target-feature=-crt-static"]
 [alias]
 xtask = "run --package xtask --"
 integration-test = "test --features integration --profile integration --workspace --test integration"
+integration-test-lsp = "test --features integration-lsp --profile integration --workspace --test integration-lsp -- --test-threads=1"
 

.github/workflows/build.yml

@@ -69,12 +69,25 @@ jobs:
           key: ${{ runner.os }}-${{ runner.arch }}-stable-v${{ env.GRAMMAR_CACHE_VERSION }}-tree-sitter-grammars-${{ hashFiles('languages.toml') }}
           restore-keys: ${{ runner.os }}-${{ runner.arch }}-stable-v${{ env.GRAMMAR_CACHE_VERSION }}-tree-sitter-grammars-
 
+      - name: Install go lsp integration tests
+        uses: actions/setup-go@v5
+        with:
+          go-version: '^1.22.0'
+
+      - name: Install gopls for lsp integration tests
+        run: go install golang.org/x/tools/gopls@latest
+
+
+
       - name: Run cargo test
         run: cargo test --workspace
 
       - name: Run cargo integration-test
         run: cargo integration-test
 
+      - name: Run cargo integration-test-lsp
+        run: cargo integration-test-lsp
+
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest, ubuntu-24.04-arm]

book/src/languages.md

@@ -75,6 +75,7 @@ These configuration keys are available:
 | `workspace-lsp-roots`     | Directories relative to the workspace root that are treated as LSP roots. Should only be set in `.helix/config.toml`. Overwrites the setting of the same name in `config.toml` if set. |
 | `persistent-diagnostic-sources` | An array of LSP diagnostic sources assumed unchanged when the language server resends the same set of diagnostics. Helix can track the position for these diagnostics internally instead. Useful for diagnostics that are recomputed on save.
 | `rainbow-brackets` | Overrides the `editor.rainbow-brackets` config key for the language |
+| `code-actions-on-save`    | List of LSP code actions to be run in order on save, for example `[{ code-action = "source.organizeImports", enabled = true }]` |
 
 ### File-type detection and the `file-types` key
 

docs/CONTRIBUTING.md

@@ -59,6 +59,14 @@ Contributors using MacOS might encounter `Too many open files (os error 24)`
 failures while running integration tests. This can be resolved by increasing
 the default value (e.g. to `10240` from `256`) by running `ulimit -n 10240`.
 
+### Language Server tests
+
+There are integration tests specific for language server integration that can be
+run with `cargo integration-test-lsp` and have additional dependencies.
+
+* [go](https://go.dev)
+* [gopls](https://pkg.go.dev/golang.org/x/tools/gopls)
+
 ## Minimum Stable Rust Version (MSRV) Policy
 
 Helix keeps an intentionally low MSRV for the sake of easy building and packaging

helix-core/src/syntax/config.rs

@@ -56,6 +56,9 @@ pub struct LanguageConfiguration {
     #[serde(default)]
     pub auto_format: bool,
 
+    #[serde(default)]
+    pub code_actions_on_save: Option<Vec<CodeActionsOnSave>>,
+
     #[serde(skip_serializing_if = "Option::is_none")]
     pub formatter: Option<FormatterConfiguration>,
 
@@ -435,6 +438,13 @@ pub struct AdvancedCompletion {
     pub default: Option<String>,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub struct CodeActionsOnSave {
+    pub code_action: String,
+    pub enabled: bool,
+}
+
 #[derive(Debug, PartialEq, Eq, Clone, Deserialize, Serialize)]
 #[serde(rename_all = "kebab-case", untagged)]
 pub enum DebugConfigCompletion {

helix-lsp/src/client.rs

@@ -12,6 +12,7 @@ use crate::lsp::{
 };
 use helix_core::{find_workspace, syntax::config::LanguageServerFeature, ChangeSet, Rope};
 use helix_loader::VERSION_AND_GIT_HASH;
+use helix_lsp_types::TextDocumentContentChangeEvent;
 use helix_stdx::path;
 use parking_lot::Mutex;
 use serde::Deserialize;
@@ -517,6 +518,27 @@ impl Client {
         }
     }
 
+    pub fn notify_sync<R: lsp::notification::Notification>(&self, params: R::Params) -> Result<()>
+    where
+        R::Params: serde::Serialize,
+    {
+        let server_tx = self.server_tx.clone();
+
+        let params = serde_json::to_value(params)?;
+
+        let notification = jsonrpc::Notification {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            method: R::METHOD.to_string(),
+            params: Self::value_into_params(params),
+        };
+
+        server_tx
+            .send(Payload::Notification(notification))
+            .map_err(|e| Error::Other(e.into()))?;
+
+        Ok(())
+    }
+
     /// Reply to a language server RPC call.
     pub fn reply(
         &self,
@@ -958,6 +980,51 @@ impl Client {
         new_text: &Rope,
         changes: &ChangeSet,
     ) -> Option<()> {
+        if let Some(content_changes) =
+            self.text_document_did_change_impl(old_text, new_text, changes)
+        {
+            return {
+                self.notify::<lsp::notification::DidChangeTextDocument>(
+                    lsp::DidChangeTextDocumentParams {
+                        text_document,
+                        content_changes,
+                    },
+                );
+                Some(())
+            };
+        }
+        None
+    }
+
+    /// Will send textDocument/didChange notification synchronously
+    pub fn text_document_did_change_sync(
+        &self,
+        text_document: lsp::VersionedTextDocumentIdentifier,
+        old_text: &Rope,
+        new_text: &Rope,
+        changes: &ChangeSet,
+    ) -> Option<Result<()>> {
+        if let Some(content_changes) =
+            self.text_document_did_change_impl(old_text, new_text, changes)
+        {
+            return Some(
+                self.notify_sync::<lsp::notification::DidChangeTextDocument>(
+                    lsp::DidChangeTextDocumentParams {
+                        text_document,
+                        content_changes,
+                    },
+                ),
+            );
+        }
+        None
+    }
+
+    pub fn text_document_did_change_impl(
+        &self,
+        old_text: &Rope,
+        new_text: &Rope,
+        changes: &ChangeSet,
+    ) -> Option<Vec<TextDocumentContentChangeEvent>> {
         let capabilities = self.capabilities.get().unwrap();
 
         // Return early if the server does not support document sync.
@@ -989,11 +1056,7 @@ impl Client {
             kind => unimplemented!("{:?}", kind),
         };
 
-        self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
-            text_document,
-            content_changes: changes,
-        });
-        Some(())
+        Some(changes)
     }
 
     pub fn text_document_did_close(&self, text_document: lsp::TextDocumentIdentifier) {

helix-term/Cargo.toml

@@ -34,6 +34,7 @@ assets = [
 default = ["git"]
 unicode-lines = ["helix-core/unicode-lines", "helix-view/unicode-lines"]
 integration = ["helix-event/integration_test"]
+integration-lsp = ["integration"]
 git = ["helix-vcs/git"]
 
 [[bin]]