test: add regression coverage for error handlers and attachmentLimits

special-pages/pages/history/integration-tests/history.spec.js

@@ -319,5 +319,85 @@ test.describe('history', () => {
             const calls = await hp.mocks.outgoing({ names: ['reportInitException'] });
             expect(calls).toHaveLength(0);
         });
+
+        test('falls back to ErrorEvent.message when event.error is null', async ({ page }, workerInfo) => {
+            const hp = HistoryTestPage.create(page, workerInfo).withEntries(0);
+            await hp.openPage();
+            await hp.hasEmptyState();
+
+            await page.evaluate(() => {
+                window.dispatchEvent(new ErrorEvent('error', { message: 'Script error.', error: null }));
+            });
+
+            const calls = await hp.mocks.waitForCallCount({ method: 'reportInitException', count: 1 });
+            expect(calls).toMatchObject([
+                {
+                    payload: {
+                        params: { message: '[uncaught] Script error.' },
+                    },
+                },
+            ]);
+        });
+
+        test("falls back to 'unknown error' when ErrorEvent has neither error nor message", async ({ page }, workerInfo) => {
+            const hp = HistoryTestPage.create(page, workerInfo).withEntries(0);
+            await hp.openPage();
+            await hp.hasEmptyState();
+
+            await page.evaluate(() => {
+                window.dispatchEvent(new ErrorEvent('error', { error: null }));
+            });
+
+            const calls = await hp.mocks.waitForCallCount({ method: 'reportInitException', count: 1 });
+            expect(calls).toMatchObject([
+                {
+                    payload: {
+                        params: { message: '[uncaught] unknown error' },
+                    },
+                },
+            ]);
+        });
+
+        test('stringifies a thrown non-Error value', async ({ page }, workerInfo) => {
+            const hp = HistoryTestPage.create(page, workerInfo).withEntries(0);
+            await hp.openPage();
+            await hp.hasEmptyState();
+
+            await page.evaluate(() => {
+                setTimeout(() => {
+                    // eslint-disable-next-line no-throw-literal -- intentional: a non-Error throw surfaces via event.error
+                    throw 'raw string';
+                }, 0);
+            });
+
+            const calls = await hp.mocks.waitForCallCount({ method: 'reportInitException', count: 1 });
+            expect(calls).toMatchObject([
+                {
+                    payload: {
+                        params: { message: '[uncaught] raw string' },
+                    },
+                },
+            ]);
+        });
+
+        test('reports primitive and nullish rejection reasons distinctly', async ({ page }, workerInfo) => {
+            const hp = HistoryTestPage.create(page, workerInfo).withEntries(0);
+            await hp.openPage();
+            await hp.hasEmptyState();
+
+            await page.evaluate(() => {
+                /* eslint-disable prefer-promise-reject-errors -- intentional: testing non-Error rejection reasons */
+                setTimeout(() => Promise.reject(undefined), 0);
+                setTimeout(() => Promise.reject(null), 0);
+                setTimeout(() => Promise.reject(0), 0);
+                /* eslint-enable prefer-promise-reject-errors */
+            });
+
+            const calls = await hp.mocks.waitForCallCount({ method: 'reportInitException', count: 3 });
+            const messages = calls.map((c) => c.payload.params.message);
+            expect(messages).toEqual(
+                expect.arrayContaining(['[unhandledrejection] undefined', '[unhandledrejection] null', '[unhandledrejection] 0']),
+            );
+        });
     });
 });

special-pages/pages/new-tab/app/omnibar/integration-tests/omnibar-attachments.spec.js

@@ -389,6 +389,27 @@ test.describe('omnibar file attachment', () => {
         await expect(omnibar.context().getByText('You can only attach 2 files at a time.')).toBeVisible();
     });
 
+    test('a partial attachmentLimits payload falls back to default file cap without crashing', async ({ page }, workerInfo) => {
+        const { ntp, omnibar } = setup(page, workerInfo);
+        await ntp.reducedMotion();
+        await ntp.openPage({
+            additional: {
+                'omnibar.mode': 'ai',
+                'omnibar.enableAiChatTools': 'true',
+                'omnibar.selectedModelId': 'claude-haiku-4-5',
+                // Simulates a malformed backend payload: present attachmentLimits but empty sections.
+                'omnibar.attachmentLimitsPartial': 'empty-sections',
+            },
+        });
+        await omnibar.ready();
+
+        await omnibar
+            .fileInput()
+            .setInputFiles(['a.pdf', 'b.pdf', 'c.pdf', 'd.pdf'].map((name) => ({ name, mimeType: 'application/pdf', buffer: PDF_BYTES })));
+        await expect(omnibar.fileChip()).toHaveCount(4);
+        await expect(omnibar.context().getByText('You can only attach 3 files at a time.')).toBeVisible();
+    });
+
     test('a file larger than the configured maxFileSizeMB is rejected with an error', async ({ page }, workerInfo) => {
         const { ntp, omnibar } = setup(page, workerInfo);
         await ntp.reducedMotion();
@@ -434,6 +455,60 @@ test.describe('omnibar file attachment', () => {
     });
 });
 
+test.describe('omnibar image attachment limits', () => {
+    test('the image cap follows the backend attachmentLimits config', async ({ page }, workerInfo) => {
+        const { ntp, omnibar } = setup(page, workerInfo);
+        await ntp.reducedMotion();
+        await ntp.openPage({
+            additional: {
+                'omnibar.mode': 'ai',
+                'omnibar.enableAiChatTools': 'true',
+                'omnibar.selectedModelId': 'gpt-4o-mini',
+                // Backend-configured cap of two images per turn (default is three).
+                'omnibar.imageMaxPerTurn': '2',
+            },
+        });
+        await omnibar.ready();
+
+        // Two images are within the configured cap — no warning.
+        await omnibar.fileInput().setInputFiles([
+            { name: 'a.png', mimeType: 'image/png', buffer: TINY_PNG },
+            { name: 'b.png', mimeType: 'image/png', buffer: TINY_PNG },
+        ]);
+        await expect(omnibar.imagePreviews()).toHaveCount(2);
+        await expect(omnibar.imageLimitWarning()).toHaveCount(0);
+
+        // A third image exceeds the configured cap of two → warning names the configured limit.
+        await omnibar.fileInput().setInputFiles({ name: 'c.png', mimeType: 'image/png', buffer: TINY_PNG });
+        await expect(omnibar.imagePreviews()).toHaveCount(3);
+        await expect(omnibar.context().getByText('You can only attach 2 images at a time.')).toBeVisible();
+        await expect(omnibar.chatSubmitButton()).toBeDisabled();
+    });
+
+    test('a partial attachmentLimits payload falls back to default image cap without crashing', async ({ page }, workerInfo) => {
+        const { ntp, omnibar } = setup(page, workerInfo);
+        await ntp.reducedMotion();
+        await ntp.openPage({
+            additional: {
+                'omnibar.mode': 'ai',
+                'omnibar.enableAiChatTools': 'true',
+                'omnibar.selectedModelId': 'gpt-4o-mini',
+                'omnibar.attachmentLimitsPartial': 'empty-sections',
+            },
+        });
+        await omnibar.ready();
+
+        await omnibar.fileInput().setInputFiles([
+            { name: 'a.png', mimeType: 'image/png', buffer: TINY_PNG },
+            { name: 'b.png', mimeType: 'image/png', buffer: TINY_PNG },
+            { name: 'c.png', mimeType: 'image/png', buffer: TINY_PNG },
+            { name: 'd.png', mimeType: 'image/png', buffer: TINY_PNG },
+        ]);
+        await expect(omnibar.imagePreviews()).toHaveCount(4);
+        await expect(omnibar.context().getByText('You can only attach 3 images at a time.')).toBeVisible();
+    });
+});
+
 test.describe('omnibar attachment coexistence', () => {
     test('files and tab content are carried independently on the same submit', async ({ page }, workerInfo) => {
         const { ntp, omnibar } = setup(page, workerInfo);

special-pages/pages/new-tab/app/omnibar/mocks/omnibar.mock-transport.js

@@ -247,12 +247,29 @@
                     config.enableAskAiSuggestion = parseBooleanQueryParam('omnibar.enableAskAiSuggestion') ?? config.enableAskAiSuggestion;
                     config.enableAttachTabs = parseBooleanQueryParam('omnibar.enableAttachTabs') ?? config.enableAttachTabs;
                     if (config.attachmentLimits) {
+                        const attachmentLimitsPartial = url.searchParams.get('omnibar.attachmentLimitsPartial');
+                        if (attachmentLimitsPartial === 'empty-sections') {
+                            config.attachmentLimits = { files: {}, images: {} };
+                        } else if (attachmentLimitsPartial === 'files-only') {
+                            config.attachmentLimits = { files: {} };
+                        } else if (attachmentLimitsPartial === 'images-only') {
+                            config.attachmentLimits = { images: {} };
+                        }
                         const imageMaxPerTurn = parseInt(url.searchParams.get('omnibar.imageMaxPerTurn') ?? '', 10);
-                        if (imageMaxPerTurn > 0) config.attachmentLimits.images.maxPerTurn = imageMaxPerTurn;
+                        if (imageMaxPerTurn > 0) {
+                            config.attachmentLimits.images ??= {};
+                            config.attachmentLimits.images.maxPerTurn = imageMaxPerTurn;
+                        }
                         const fileMaxPerConversation = parseInt(url.searchParams.get('omnibar.fileMaxPerConversation') ?? '', 10);
-                        if (fileMaxPerConversation > 0) config.attachmentLimits.files.maxPerConversation = fileMaxPerConversation;
+                        if (fileMaxPerConversation > 0) {
+                            config.attachmentLimits.files ??= {};
+                            config.attachmentLimits.files.maxPerConversation = fileMaxPerConversation;
+                        }
                         const fileMaxFileSizeMB = parseInt(url.searchParams.get('omnibar.fileMaxFileSizeMB') ?? '', 10);
-                        if (fileMaxFileSizeMB > 0) config.attachmentLimits.files.maxFileSizeMB = fileMaxFileSizeMB;
+                        if (fileMaxFileSizeMB > 0) {
+                            config.attachmentLimits.files ??= {};
+                            config.attachmentLimits.files.maxFileSizeMB = fileMaxFileSizeMB;
+                        }
                     }
                     return config;
                 }

special-pages/pages/new-tab/integration-tests/new-tab.spec.js

@@ -214,5 +214,89 @@ test.describe('newtab widgets', () => {
             const calls = await ntp.mocks.outgoing({ names: ['reportInitException'] });
             expect(calls).toHaveLength(0);
         });
+
+        test('falls back to ErrorEvent.message when event.error is null', async ({ page }, workerInfo) => {
+            const ntp = NewtabPage.create(page, workerInfo);
+            await ntp.reducedMotion();
+            await ntp.openPage();
+            await ntp.waitForCustomizer();
+
+            await page.evaluate(() => {
+                window.dispatchEvent(new ErrorEvent('error', { message: 'Script error.', error: null }));
+            });
+
+            const calls = await ntp.mocks.waitForCallCount({ method: 'reportInitException', count: 1 });
+            expect(calls).toMatchObject([
+                {
+                    payload: {
+                        params: { message: '[uncaught] Script error.' },
+                    },
+                },
+            ]);
+        });
+
+        test("falls back to 'unknown error' when ErrorEvent has neither error nor message", async ({ page }, workerInfo) => {
+            const ntp = NewtabPage.create(page, workerInfo);
+            await ntp.reducedMotion();
+            await ntp.openPage();
+            await ntp.waitForCustomizer();
+
+            await page.evaluate(() => {
+                window.dispatchEvent(new ErrorEvent('error', { error: null }));
+            });
+
+            const calls = await ntp.mocks.waitForCallCount({ method: 'reportInitException', count: 1 });
+            expect(calls).toMatchObject([
+                {
+                    payload: {
+                        params: { message: '[uncaught] unknown error' },
+                    },
+                },
+            ]);
+        });
+
+        test('stringifies a thrown non-Error value', async ({ page }, workerInfo) => {
+            const ntp = NewtabPage.create(page, workerInfo);
+            await ntp.reducedMotion();
+            await ntp.openPage();
+            await ntp.waitForCustomizer();
+
+            await page.evaluate(() => {
+                setTimeout(() => {
+                    // eslint-disable-next-line no-throw-literal -- intentional: a non-Error throw surfaces via event.error
+                    throw 'raw string';
+                }, 0);
+            });
+
+            const calls = await ntp.mocks.waitForCallCount({ method: 'reportInitException', count: 1 });
+            expect(calls).toMatchObject([
+                {
+                    payload: {
+                        params: { message: '[uncaught] raw string' },
+                    },
+                },
+            ]);
+        });
+
+        test('reports primitive and nullish rejection reasons distinctly', async ({ page }, workerInfo) => {
+            const ntp = NewtabPage.create(page, workerInfo);
+            await ntp.reducedMotion();
+            await ntp.openPage();
+            await ntp.waitForCustomizer();
+
+            await page.evaluate(() => {
+                /* eslint-disable prefer-promise-reject-errors -- intentional: testing non-Error rejection reasons */
+                setTimeout(() => Promise.reject(undefined), 0);
+                setTimeout(() => Promise.reject(null), 0);
+                setTimeout(() => Promise.reject(0), 0);
+                /* eslint-enable prefer-promise-reject-errors */
+            });
+
+            const calls = await ntp.mocks.waitForCallCount({ method: 'reportInitException', count: 3 });
+            const messages = calls.map((c) => c.payload.params.message);
+            expect(messages).toEqual(
+                expect.arrayContaining(['[unhandledrejection] undefined', '[unhandledrejection] null', '[unhandledrejection] 0']),
+            );
+        });
     });
 });