Handle custom PeekDocumentsRequest to show macro expansions in a peeked editor (#945)

Author: lokesh-tr

src/sourcekit-lsp/LanguageClientManager.ts

@@ -20,6 +20,7 @@ import { isPathInsidePath, swiftRuntimeEnv } from "../utilities/utilities";
 import { Version } from "../utilities/version";
 import { FolderEvent, WorkspaceContext } from "../WorkspaceContext";
 import { activateLegacyInlayHints } from "./inlayHints";
+import { activatePeekDocuments } from "./peekDocuments";
 import { FolderContext } from "../FolderContext";
 import { LanguageClient } from "vscode-languageclient/node";
 import { ArgumentFilter, BuildFlags } from "../toolchain/BuildFlags";
@@ -108,6 +109,7 @@ export class LanguageClientManager {
     private languageClient: langclient.LanguageClient | null | undefined;
     private cancellationToken?: vscode.CancellationTokenSource;
     private legacyInlayHints?: vscode.Disposable;
+    private peekDocuments?: vscode.Disposable;
     private restartedPromise?: Promise<void>;
     private currentWorkspaceFolder?: vscode.Uri;
     private waitingOnRestartCount: number;
@@ -244,6 +246,7 @@ export class LanguageClientManager {
         this.cancellationToken?.cancel();
         this.cancellationToken?.dispose();
         this.legacyInlayHints?.dispose();
+        this.peekDocuments?.dispose();
         this.subscriptions.forEach(item => item.dispose());
         this.languageClient?.stop();
         this.namedOutputChannels.forEach(channel => channel.dispose());
@@ -392,6 +395,8 @@ export class LanguageClientManager {
         this.currentWorkspaceFolder = workspaceFolder?.uri;
         this.legacyInlayHints?.dispose();
         this.legacyInlayHints = undefined;
+        this.peekDocuments?.dispose();
+        this.peekDocuments = undefined;
         if (client) {
             this.cancellationToken?.cancel();
             this.cancellationToken?.dispose();
@@ -559,6 +564,9 @@ export class LanguageClientManager {
                 })(),
             },
             errorHandler: new SourceKitLSPErrorHandler(5),
+            initializationOptions: {
+                "workspace/peekDocuments": true, // workaround for client capability to handle `PeekDocumentsRequest`
+            },
         };
 
         return new langclient.LanguageClient(
@@ -604,6 +612,8 @@ export class LanguageClientManager {
                 if (this.workspaceContext.swiftVersion.isLessThan(new Version(5, 7, 0))) {
                     this.legacyInlayHints = activateLegacyInlayHints(client);
                 }
+
+                this.peekDocuments = activatePeekDocuments(client);
             })
             .catch(reason => {
                 this.workspaceContext.outputChannel.log(`${reason}`);

src/sourcekit-lsp/lspExtensions.ts

@@ -14,9 +14,48 @@
 
 import * as ls from "vscode-languageserver-protocol";
 import * as langclient from "vscode-languageclient/node";
+import * as vscode from "vscode";
 
 // Definitions for non-standard requests used by sourcekit-lsp
 
+// Peek Documents
+export interface PeekDocumentsParams {
+    /**
+     * The `DocumentUri` of the text document in which to show the "peeked" editor
+     */
+    uri: langclient.DocumentUri;
+
+    /**
+     * The `Position` in the given text document in which to show the "peeked editor"
+     */
+    position: vscode.Position;
+
+    /**
+     * An array `DocumentUri` of the documents to appear inside the "peeked" editor
+     */
+    locations: langclient.DocumentUri[];
+}
+
+/**
+ * Response to indicate the `success` of the `PeekDocumentsRequest`
+ */
+export interface PeekDocumentsResult {
+    success: boolean;
+}
+
+/**
+ * Request from the server to the client to show the given documents in a "peeked" editor.
+ *
+ * This request is handled by the client to show the given documents in a "peeked" editor (i.e. inline with / inside the editor canvas).
+ *
+ * It requires the experimental client capability `"workspace/peekDocuments"` to use.
+ */
+export const PeekDocumentsRequest = new langclient.RequestType<
+    PeekDocumentsParams,
+    PeekDocumentsResult,
+    unknown
+>("workspace/peekDocuments");
+
 // Inlay Hints (pre Swift 5.6)
 export interface LegacyInlayHintsParams {
     /**

src/sourcekit-lsp/peekDocuments.ts

@@ -0,0 +1,37 @@
+import * as vscode from "vscode";
+import * as langclient from "vscode-languageclient/node";
+import { PeekDocumentsParams, PeekDocumentsRequest } from "./lspExtensions";
+
+export function activatePeekDocuments(client: langclient.LanguageClient): vscode.Disposable {
+    const peekDocuments = client.onRequest(
+        PeekDocumentsRequest.method,
+        async (params: PeekDocumentsParams) => {
+            const locations = params.locations.map(uri => {
+                const location = new vscode.Location(
+                    vscode.Uri.from({
+                        scheme: "file",
+                        path: new URL(uri).pathname,
+                    }),
+                    new vscode.Position(0, 0)
+                );
+
+                return location;
+            });
+
+            await vscode.commands.executeCommand(
+                "editor.action.peekLocations",
+                vscode.Uri.from({
+                    scheme: "file",
+                    path: new URL(params.uri).pathname,
+                }),
+                new vscode.Position(params.position.line, params.position.character),
+                locations,
+                "peek"
+            );
+
+            return { success: true };
+        }
+    );
+
+    return peekDocuments;
+}