fix: do not error if the dialog was already handled

src/tools/pages.ts

@@ -6,6 +6,8 @@
 
 import z from 'zod';
 
+import {logger} from '../logger.js';
+
 import {ToolCategories} from './categories.js';
 import {CLOSE_PAGE_ERROR, defineTool} from './ToolDefinition.js';
 
@@ -195,12 +197,22 @@ export const handleDialog = defineTool({
 
     switch (request.params.action) {
       case 'accept': {
-        await dialog.accept(request.params.promptText);
+        try {
+          await dialog.accept(request.params.promptText);
+        } catch (err) {
+          // Likely already handled by the user outside of MCP.
+          logger(err);
+        }
         response.appendResponseLine('Successfully accepted the dialog');
         break;
       }
       case 'dismiss': {
-        await dialog.dismiss();
+        try {
+          await dialog.dismiss();
+        } catch (err) {
+          // Likely already handled.
+          logger(err);
+        }
         response.appendResponseLine('Successfully dismissed the dialog');
         break;
       }

tests/tools/pages.test.ts

@@ -6,6 +6,8 @@
 import assert from 'node:assert';
 import {describe, it} from 'node:test';
 
+import type {Dialog} from 'puppeteer-core';
+
 import {
   listPages,
   newPage,
@@ -265,5 +267,34 @@ describe('pages', () => {
         );
       });
     });
+    it('can dismiss alread dismissed dialog dialogs', async () => {
+      await withBrowser(async (response, context) => {
+        const page = context.getSelectedPage();
+        const dialogPromise = new Promise<Dialog>(resolve => {
+          page.on('dialog', dialog => {
+            resolve(dialog);
+          });
+        });
+        page.evaluate(() => {
+          alert('test');
+        });
+        const dialog = await dialogPromise;
+        await dialog.dismiss();
+        await handleDialog.handler(
+          {
+            params: {
+              action: 'dismiss',
+            },
+          },
+          response,
+          context,
+        );
+        assert.strictEqual(context.getDialog(), undefined);
+        assert.strictEqual(
+          response.responseLines[0],
+          'Successfully dismissed the dialog',
+        );
+      });
+    });
   });
 });