feat: expose recent tinymist logs to tools and AI agents

editors/vscode/src/extension.shared.ts

@@ -158,6 +158,9 @@ export async function tinymistActivate(
       await tinymistDeactivate(trait);
       await tinymistActivate(context, trait);
     }),
+    commands.registerCommand("tinymist.getLogText", (options?: { maxChars?: number }) => {
+      return tinymist.getLogText(options?.maxChars);
+    }),
     commands.registerCommand("tinymist.showLog", () => tinymist.showLog()),
   );
   // Activates platform-dependent features

editors/vscode/src/lsp.ts

@@ -93,11 +93,103 @@ interface JumpInfo {
   end: [number, number] | null;
 }
 
+class BufferedOutputChannel implements vscode.OutputChannel {
+  private readonly channel: vscode.OutputChannel;
+  private buffer = "";
+
+  constructor(
+    name: string,
+    languageId?: string,
+    private readonly maxChars: number = 200_000,
+  ) {
+    this.channel = languageId
+      ? vscode.window.createOutputChannel(name, languageId)
+      : vscode.window.createOutputChannel(name);
+  }
+
+  get name(): string {
+    return this.channel.name;
+  }
+
+  append(value: string): void {
+    this.push(value);
+    this.channel.append(value);
+  }
+
+  appendLine(value: string): void {
+    this.push(`${value}\n`);
+    this.channel.appendLine(value);
+  }
+
+  clear(): void {
+    this.buffer = "";
+    this.channel.clear();
+  }
+
+  show(preserveFocus?: boolean): void;
+  show(column?: vscode.ViewColumn, preserveFocus?: boolean): void;
+  show(
+    columnOrPreserveFocus?: vscode.ViewColumn | boolean,
+    preserveFocus?: boolean,
+  ): void {
+    if (typeof columnOrPreserveFocus === "boolean" || columnOrPreserveFocus === undefined) {
+      this.channel.show(columnOrPreserveFocus);
+      return;
+    }
+
+    this.channel.show(columnOrPreserveFocus, preserveFocus);
+  }
+
+  hide(): void {
+    this.channel.hide();
+  }
+
+  replace(value: string): void {
+    this.buffer = "";
+    this.push(value);
+
+    if ("replace" in this.channel && typeof this.channel.replace === "function") {
+      this.channel.replace(value);
+      return;
+    }
+
+    this.channel.clear();
+    this.channel.append(value);
+  }
+
+  dispose(): void {
+    this.channel.dispose();
+  }
+
+  getText(maxChars?: number): string {
+    if (maxChars === 0) {
+      return "";
+    }
+
+    if (maxChars === undefined || maxChars < 0 || this.buffer.length <= maxChars) {
+      return this.buffer;
+    }
+
+    return this.buffer.slice(-maxChars);
+  }
+
+  private push(value: string): void {
+    if (!value || this.maxChars <= 0) {
+      return;
+    }
+
+    this.buffer += value;
+    if (this.buffer.length > this.maxChars) {
+      this.buffer = this.buffer.slice(-this.maxChars);
+    }
+  }
+}
+
 export class LanguageState {
   static Client: typeof createSystemLanguageClient = undefined!;
   static HoverTmpStorage?: typeof HoverTmpStorage = undefined;
 
-  outputChannel: vscode.OutputChannel = vscode.window.createOutputChannel("Tinymist Typst", "log");
+  outputChannel = new BufferedOutputChannel("Tinymist Typst", "log");
   context: vscode.ExtensionContext = undefined!;
   client: LanguageClient | undefined = undefined;
   _watcher: vscode.FileSystemWatcher | undefined = undefined;
@@ -389,6 +481,10 @@ export class LanguageState {
     }
   }
 
+  getLogText(maxChars?: number) {
+    return this.outputChannel.getText(maxChars);
+  }
+
   /**
    * The commands group for the *Document Preview* feature. This feature is used to preview multiple
    * documents at the same time.

editors/vscode/src/test/e2e/simple-docs.test.ts

@@ -1,6 +1,7 @@
 // You can import and use all API from the 'vscode' module
 // as well as import your extension to test it
 import * as vscode from "vscode";
+import { tinymist } from "../../lsp";
 import type { Context } from ".";
 
 export async function getTests(ctx: Context) {
@@ -77,5 +78,23 @@ export async function getTests(ctx: Context) {
       // close the editor
       await vscode.commands.executeCommand("workbench.action.closeActiveEditor");
     });
+
+    suite.addTest("get recent log text", async () => {
+      const marker = `agent-log-marker-${Date.now()}`;
+      tinymist.outputChannel.append(marker);
+
+      const logs = await vscode.commands.executeCommand<string>("tinymist.getLogText");
+      ctx.expect(logs).to.include(marker);
+
+      const none = await vscode.commands.executeCommand<string>("tinymist.getLogText", {
+        maxChars: 0,
+      });
+      ctx.expect(none).to.equal("");
+
+      const tail = await vscode.commands.executeCommand<string>("tinymist.getLogText", {
+        maxChars: 16,
+      });
+      ctx.expect(tail.length).to.be.lessThanOrEqual(16);
+    });
   });
 }