chore: parse response in tests (#796)

src/context.ts

@@ -93,8 +93,8 @@ export class Context {
 
     if (!this._tabs.length) {
       return [
-        '### No open tabs',
-        'Use the "browser_navigate" tool to navigate to a page first.',
+        '### Open tabs',
+        'No open tabs. Use the "browser_navigate" tool to navigate to a page first.',
         '',
       ];
     }

src/mcp/server.ts

@@ -88,12 +88,12 @@ export function createServer(backend: ServerBackend, runHeartbeat: boolean): Ser
     }
 
     const errorResult = (...messages: string[]) => ({
-      content: [{ type: 'text', text: messages.join('\n') }],
+      content: [{ type: 'text', text: '### Result\n' + messages.join('\n') }],
       isError: true,
     });
     const tool = tools.find(tool => tool.name === request.params.name) as ToolSchema<any>;
     if (!tool)
-      return errorResult(`Tool "${request.params.name}" not found`);
+      return errorResult(`Error: Tool "${request.params.name}" not found`);
 
     try {
       return await backend.callTool(tool, tool.inputSchema.parse(request.params.arguments || {}));

src/response.ts

@@ -28,6 +28,7 @@ export class Response {
 
   readonly toolName: string;
   readonly toolArgs: Record<string, any>;
+  private _isError: boolean | undefined;
 
   constructor(context: Context, toolName: string, toolArgs: Record<string, any>) {
     this._context = context;
@@ -39,6 +40,11 @@ export class Response {
     this._result.push(result);
   }
 
+  addError(error: string) {
+    this._result.push(`Error: ${error}`);
+    this._isError = true;
+  }
+
   result() {
     return this._result.join('\n');
   }
@@ -77,7 +83,7 @@ export class Response {
     return this._snapshot;
   }
 
-  async serialize(): Promise<{ content: (TextContent | ImageContent)[] }> {
+  async serialize(): Promise<{ content: (TextContent | ImageContent)[], isError?: boolean }> {
     const response: string[] = [];
 
     // Start with command result.
@@ -116,6 +122,6 @@ ${this._code.join('\n')}
         content.push({ type: 'image', data: image.data.toString('base64'), mimeType: image.contentType });
     }
 
-    return { content };
+    return { content, isError: this._isError };
   }
 }

src/tools/common.ts

@@ -49,7 +49,6 @@ const resize = defineTabTool({
   },
 
   handle: async (tab, params, response) => {
-    response.addCode(`// Resize browser window to ${params.width}x${params.height}`);
     response.addCode(`await page.setViewportSize({ width: ${params.width}, height: ${params.height} });`);
 
     await tab.waitForCompletion(async () => {

src/tools/keyboard.ts

@@ -67,11 +67,9 @@ const type = defineTabTool({
     await tab.waitForCompletion(async () => {
       if (params.slowly) {
         response.setIncludeSnapshot();
-        response.addCode(`// Press "${params.text}" sequentially into "${params.element}"`);
         response.addCode(`await page.${await generateLocator(locator)}.pressSequentially(${javascript.quote(params.text)});`);
         await locator.pressSequentially(params.text);
       } else {
-        response.addCode(`// Fill "${params.text}" into "${params.element}"`);
         response.addCode(`await page.${await generateLocator(locator)}.fill(${javascript.quote(params.text)});`);
         await locator.fill(params.text);
       }

src/tools/navigate.ts

@@ -35,7 +35,6 @@ const navigate = defineTool({
     await tab.navigate(params.url);
 
     response.setIncludeSnapshot();
-    response.addCode(`// Navigate to ${params.url}`);
     response.addCode(`await page.goto('${params.url}');`);
   },
 });
@@ -53,7 +52,6 @@ const goBack = defineTabTool({
   handle: async (tab, params, response) => {
     await tab.page.goBack();
     response.setIncludeSnapshot();
-    response.addCode(`// Navigate back`);
     response.addCode(`await page.goBack();`);
   },
 });
@@ -70,7 +68,6 @@ const goForward = defineTabTool({
   handle: async (tab, params, response) => {
     await tab.page.goForward();
     response.setIncludeSnapshot();
-    response.addCode(`// Navigate forward`);
     response.addCode(`await page.goForward();`);
   },
 });

src/tools/pdf.ts

@@ -37,7 +37,6 @@ const pdf = defineTabTool({
 
   handle: async (tab, params, response) => {
     const fileName = await outputFile(tab.context.config, params.filename ?? `page-${new Date().toISOString()}.pdf`);
-    response.addCode(`// Save page as ${fileName}`);
     response.addCode(`await page.pdf(${javascript.formatObject({ path: fileName })});`);
     response.addResult(`Saved page as ${fileName}`);
     await tab.page.pdf({ path: fileName });

src/tools/snapshot.ts

@@ -63,13 +63,11 @@ const click = defineTabTool({
     const button = params.button;
     const buttonAttr = button ? `{ button: '${button}' }` : '';
 
-    if (params.doubleClick) {
-      response.addCode(`// Double click ${params.element}`);
+    if (params.doubleClick)
       response.addCode(`await page.${await generateLocator(locator)}.dblclick(${buttonAttr});`);
-    } else {
-      response.addCode(`// Click ${params.element}`);
+    else
       response.addCode(`await page.${await generateLocator(locator)}.click(${buttonAttr});`);
-    }
+
 
     await tab.waitForCompletion(async () => {
       if (params.doubleClick)
@@ -151,7 +149,6 @@ const selectOption = defineTabTool({
     response.setIncludeSnapshot();
 
     const locator = await tab.refLocator(params);
-    response.addCode(`// Select options [${params.values.join(', ')}] in ${params.element}`);
     response.addCode(`await page.${await generateLocator(locator)}.selectOption(${javascript.formatObject(params.values)});`);
 
     await tab.waitForCompletion(async () => {

src/tools/tool.ts

@@ -60,10 +60,11 @@ export function defineTabTool<Input extends z.Schema>(tool: TabTool<Input>): Too
       const tab = context.currentTabOrDie();
       const modalStates = tab.modalStates().map(state => state.type);
       if (tool.clearsModalState && !modalStates.includes(tool.clearsModalState))
-        throw new Error(`The tool "${tool.schema.name}" can only be used when there is related modal state present.\n` + tab.modalStatesMarkdown().join('\n'));
-      if (!tool.clearsModalState && modalStates.length)
-        throw new Error(`Tool "${tool.schema.name}" does not handle the modal state.\n` + tab.modalStatesMarkdown().join('\n'));
-      return tool.handle(tab, params, response);
+        response.addError(`The tool "${tool.schema.name}" can only be used when there is related modal state present.\n` + tab.modalStatesMarkdown().join('\n'));
+      else if (!tool.clearsModalState && modalStates.length)
+        response.addError(`Tool "${tool.schema.name}" does not handle the modal state.\n` + tab.modalStatesMarkdown().join('\n'));
+      else
+        return tool.handle(tab, params, response);
     },
   };
 }