Notify sourcekit-lsp of active document changes

plemarquand · plemarquand · commit ad20f13ccf0d · 2025-02-24T12:00:10.000-05:00
`sourcekit-lsp` recently added an LSP extension method to notify the server of the active documnent, so it doesn't need to infer it from information in other requests. This capability was added in swiftlang/sourcekit-lsp#1989.
diff --git a/src/TestExplorer/LSPTestDiscovery.ts b/src/TestExplorer/LSPTestDiscovery.ts
@@ -20,7 +20,10 @@ import {
     WorkspaceTestsRequest,
 } from "../sourcekit-lsp/extensions";
 import { SwiftPackage, TargetType } from "../SwiftPackage";
-import { LanguageClientManager } from "../sourcekit-lsp/LanguageClientManager";
+import {
+    checkExperimentalCapability,
+    LanguageClientManager,
+} from "../sourcekit-lsp/LanguageClientManager";
 import { LanguageClient } from "vscode-languageclient/node";
 
 /**
@@ -45,7 +48,7 @@ export class LSPTestDiscovery {
         return await this.languageClient.useLanguageClient(async (client, token) => {
             // Only use the lsp for this request if it supports the
             // textDocument/tests method, and is at least version 2.
-            if (this.checkExperimentalCapability(client, TextDocumentTestsRequest.method, 2)) {
+            if (checkExperimentalCapability(client, TextDocumentTestsRequest.method, 2)) {
                 const testsInDocument = await client.sendRequest(
                     TextDocumentTestsRequest.type,
                     { textDocument: { uri: document.toString() } },
@@ -66,7 +69,7 @@ export class LSPTestDiscovery {
         return await this.languageClient.useLanguageClient(async (client, token) => {
             // Only use the lsp for this request if it supports the
             // workspace/tests method, and is at least version 2.
-            if (this.checkExperimentalCapability(client, WorkspaceTestsRequest.method, 2)) {
+            if (checkExperimentalCapability(client, WorkspaceTestsRequest.method, 2)) {
                 const tests = await client.sendRequest(WorkspaceTestsRequest.type, token);
                 return this.transformToTestClass(client, swiftPackage, tests);
             } else {
@@ -75,23 +78,6 @@ export class LSPTestDiscovery {
         });
     }
 
-    /**
-     * Returns `true` if the LSP supports the supplied `method` at or
-     * above the supplied `minVersion`.
-     */
-    private checkExperimentalCapability(
-        client: LanguageClient,
-        method: string,
-        minVersion: number
-    ) {
-        const experimentalCapability = client.initializeResult?.capabilities.experimental;
-        if (!experimentalCapability) {
-            throw new Error(`${method} requests not supported`);
-        }
-        const targetCapability = experimentalCapability[method];
-        return (targetCapability?.version ?? -1) >= minVersion;
-    }
-
     /**
      * Convert from `LSPTestItem[]` to `TestDiscovery.TestClass[]`,
      * updating the format of the location.
diff --git a/src/sourcekit-lsp/LanguageClientManager.ts b/src/sourcekit-lsp/LanguageClientManager.ts
@@ -47,6 +47,7 @@ import { activateGetReferenceDocument } from "./getReferenceDocument";
 import { uriConverters } from "./uriConverters";
 import { LanguageClientFactory } from "./LanguageClientFactory";
 import { SourceKitLogMessageNotification, SourceKitLogMessageParams } from "./extensions";
+import { activateDidChangeActiveDocument } from "./didChangeActiveDocument";
 
 /**
  * Manages the creation and destruction of Language clients as we move between
@@ -136,6 +137,7 @@ export class LanguageClientManager implements vscode.Disposable {
     private legacyInlayHints?: vscode.Disposable;
     private peekDocuments?: vscode.Disposable;
     private getReferenceDocument?: vscode.Disposable;
+    private didChangeActiveDocument?: vscode.Disposable;
     private restartedPromise?: Promise<void>;
     private currentWorkspaceFolder?: vscode.Uri;
     private waitingOnRestartCount: number;
@@ -666,6 +668,13 @@ export class LanguageClientManager implements vscode.Disposable {
             };
         }
 
+        if (this.swiftVersion.isGreaterThanOrEqual(new Version(6, 1, 0))) {
+            options = {
+                ...options,
+                "window/didChangeActiveDocument": true, // the client can send `window/didChangeActiveDocument` notifications
+            };
+        }
+
         if (configuration.swiftSDK !== "") {
             options = {
                 ...options,
@@ -715,6 +724,8 @@ export class LanguageClientManager implements vscode.Disposable {
                 this.peekDocuments = activatePeekDocuments(client);
                 this.getReferenceDocument = activateGetReferenceDocument(client);
                 this.workspaceContext.subscriptions.push(this.getReferenceDocument);
+                this.didChangeActiveDocument = activateDidChangeActiveDocument(client);
+                this.workspaceContext.subscriptions.push(this.didChangeActiveDocument);
             })
             .catch(reason => {
                 this.workspaceContext.outputChannel.log(`${reason}`);
@@ -846,3 +857,20 @@ type SourceKitDocumentSelector = {
     scheme: string;
     language: string;
 }[];
+
+/**
+ * Returns `true` if the LSP supports the supplied `method` at or
+ * above the supplied `minVersion`.
+ */
+export function checkExperimentalCapability(
+    client: LanguageClient,
+    method: string,
+    minVersion: number
+) {
+    const experimentalCapability = client.initializeResult?.capabilities.experimental;
+    if (!experimentalCapability) {
+        throw new Error(`${method} requests not supported`);
+    }
+    const targetCapability = experimentalCapability[method];
+    return (targetCapability?.version ?? -1) >= minVersion;
+}
diff --git a/src/sourcekit-lsp/didChangeActiveDocument.ts b/src/sourcekit-lsp/didChangeActiveDocument.ts
@@ -0,0 +1,49 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the VS Code Swift open source project
+//
+// Copyright (c) 2024 the VS Code Swift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of VS Code Swift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import * as vscode from "vscode";
+import * as langclient from "vscode-languageclient/node";
+import { checkExperimentalCapability } from "./LanguageClientManager";
+import { DidChangeActiveDocumentNotification } from "./extensions/DidChangeActiveDocumentRequest";
+
+export function activateDidChangeActiveDocument(
+    client: langclient.LanguageClient
+): vscode.Disposable {
+    const disposable = vscode.window.onDidChangeActiveTextEditor(event => {
+        if (
+            event &&
+            checkExperimentalCapability(client, DidChangeActiveDocumentNotification.method, 1)
+        ) {
+            client.sendNotification(DidChangeActiveDocumentNotification.method, {
+                textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(
+                    event.document
+                ),
+            });
+        }
+    });
+
+    // Fire an inital notification
+    const activeEditor = vscode.window.activeTextEditor;
+    if (
+        activeEditor &&
+        checkExperimentalCapability(client, DidChangeActiveDocumentNotification.method, 1)
+    ) {
+        client.sendNotification(DidChangeActiveDocumentNotification.method, {
+            textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(
+                activeEditor.document
+            ),
+        });
+    }
+    return disposable;
+}
diff --git a/src/sourcekit-lsp/extensions/DidChangeActiveDocumentRequest.ts b/src/sourcekit-lsp/extensions/DidChangeActiveDocumentRequest.ts
@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the VS Code Swift open source project
+//
+// Copyright (c) 2021-2024 the VS Code Swift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of VS Code Swift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import { MessageDirection, NotificationType, TextDocumentIdentifier } from "vscode-languageclient";
+
+// We use namespaces to store request information just like vscode-languageclient
+/* eslint-disable @typescript-eslint/no-namespace */
+
+export interface DidChangeActiveDocumentParams {
+    /**
+     * The document that is being displayed in the active editor.
+     */
+    textDocument: TextDocumentIdentifier;
+}
+
+/**
+ * Notify the server that the active document has changed.
+ */
+export namespace DidChangeActiveDocumentNotification {
+    export const method = "window/didChangeActiveDocument" as const;
+    export const messageDirection: MessageDirection = MessageDirection.clientToServer;
+    export const type = new NotificationType<DidChangeActiveDocumentParams>(method);
+}
diff --git a/test/unit-tests/sourcekit-lsp/LanguageClientManager.test.ts b/test/unit-tests/sourcekit-lsp/LanguageClientManager.test.ts
@@ -123,6 +123,13 @@ suite("LanguageClientManager Suite", () => {
                     dispose: mockFn(),
                 })
             ),
+            initializeResult: {
+                capabilities: {
+                    experimental: {
+                        "window/didChangeActiveDocument": true,
+                    },
+                },
+            },
             start: mockFn(s =>
                 s.callsFake(async () => {
                     const oldState = languageClientMock.state;
