Add missing test (jaegertracing#3453)

Follow-up to jaegertracing#3226

Signed-off-by: Yuri Shkuro <github@ysh.us>

Author: yurishkuro

packages/jaeger-ui/src/utils/tracking/ga-coverage.test.js

@@ -0,0 +1,167 @@
+// Copyright (c) 2026 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+// Mock dependencies
+jest.mock('../constants', () => ({
+  getAppEnvironment: jest.fn(() => 'production'),
+  shouldDebugGoogleAnalytics: jest.fn(() => true),
+}));
+
+jest.mock('../prefix-url', () => s => s);
+
+describe('GA Coverage', () => {
+  let originalFetch;
+  let mockFetch;
+  let GA;
+  let trackNavigation;
+  let captureException;
+
+  beforeEach(() => {
+    jest.resetModules();
+
+    window.dataLayer = [];
+    jest.clearAllMocks();
+    originalFetch = window.fetch;
+    mockFetch = jest.fn().mockResolvedValue({ status: 200, json: () => ({}) });
+    window.fetch = mockFetch;
+
+    // Require modules after reset
+    GA = require('./ga').default;
+    const ec = require('./error-capture');
+    trackNavigation = ec.trackNavigation;
+    captureException = ec.captureException;
+
+    // Mock site-prefix via doMock since it might be cached?
+    // jest.mock persists across resetModules if defined outside?
+    // It's safer to rely on the top level mock or define it here if needed.
+    jest.doMock('../../site-prefix', () => '/prefix/');
+  });
+
+  afterEach(() => {
+    window.fetch = originalFetch;
+  });
+
+  const config = {
+    tracking: {
+      gaID: 'UA-TEST',
+      trackErrors: true,
+      cookiesToDimensions: [
+        { cookie: 'my-cookie', dimension: 'dim1' },
+        { cookie: 'missing-cookie', dimension: 'dim2' },
+      ],
+    },
+  };
+
+  it('initializes with cookies to dimensions', () => {
+    document.cookie = 'my-cookie=foo';
+    const ga = GA(config, 'v1', 'v1-long');
+    ga.init();
+
+    const setCmd = window.dataLayer.find(cmd => cmd[0] === 'set' && cmd[1].dim1 === 'foo');
+    expect(setCmd).toBeDefined();
+  });
+
+  it('formats various breadcrumbs and error info', async () => {
+    const ga = GA(config, 'v1', 'v1-long');
+    ga.init();
+
+    // 1. Navigation crumbs
+    trackNavigation('/dependencies'); // dp
+    trackNavigation('/trace/123'); // tr
+    trackNavigation('/search?x=y'); // sd
+    trackNavigation('/search'); // sr
+    trackNavigation('/'); // rt
+    trackNavigation('/unknown'); // ??
+    window.history.pushState({}, '', '/unknown');
+
+    // 2. Fetch crumbs
+    await window.fetch('/api/services'); // svc
+    await window.fetch('/api/unknown/operations'); // op
+    await window.fetch('/api/traces?service=x'); // sr
+    await window.fetch('/api/traces/123'); // tr
+    await window.fetch('/api/dependencies'); // dp
+    await window.fetch('/foo.js'); // __IGNORE__
+
+    // Add non-200 fetch
+    mockFetch.mockResolvedValueOnce({ status: 500 });
+    await window.fetch('/api/services'); // [svc|500]
+
+    // 3. UI crumbs
+    const div = document.createElement('div');
+    div.className = 'ub-ignore MyClass';
+    div.id = 'my-id';
+    document.body.appendChild(div);
+    for (let i = 0; i < 5; i++) {
+      div.click();
+    }
+
+    // Fill breadcrumbs with errors to trigger truncation
+    // 20 crumbs * 50 chars = 1000 chars > 498
+    for (let i = 0; i < 25; i++) {
+      try {
+        throw new Error('long error message filling up the breadcrumbs buffer ' + i);
+      } catch (e) {
+        captureException(e);
+      }
+    }
+
+    // 4. Trigger Final Error
+    const error = new Error('Final Test Error');
+    captureException(error);
+
+    // Verify GA event exception (last one)
+    // window.dataLayer has many events now. Find the last one matching final error.
+    const exceptionEvents = window.dataLayer.filter(e => e[0] === 'event' && e[1] === 'exception');
+    const lastException = exceptionEvents[exceptionEvents.length - 1];
+    expect(lastException).toBeDefined();
+    expect(lastException[2].description).toContain('! Final Test Error');
+
+    const eventCalls = window.dataLayer.filter(
+      e => e[0] === 'event' && e[2].event_category === 'jaeger/??/error'
+    );
+    const lastEvent = eventCalls[eventCalls.length - 1];
+    expect(lastEvent).toBeDefined();
+
+    const eventLabel = lastEvent[2].event_label;
+    // Expect truncation. Start crumbs (nav, fetch) might be pushed out by buffer logic (20 limit).
+    // But we filled with 25 errors. So only errors remain.
+    // So checking for [svc] is invalid now as it was shifted out.
+
+    // Check that label IS truncated (length check? or content check?)
+    // Max length 499.
+    expect(eventLabel.length).toBeLessThanOrEqual(499);
+    // It should contain the last error messages
+    expect(eventLabel).toContain('filling up the breadcrumbs buffer');
+    // It should NOT contain [svc] (shifted out)
+    expect(eventLabel).not.toContain('[svc]');
+  });
+
+  it('handles stack trace missing', () => {
+    const ga = GA(config, 'v1', 'v1-long');
+    ga.init();
+
+    class NoStackError extends Error {
+      constructor(m) {
+        super(m);
+        this.stack = undefined;
+      }
+    }
+    const error = new NoStackError('msg');
+    captureException(error);
+
+    const exceptionEvent = window.dataLayer.find(e => e[0] === 'event' && e[1] === 'exception');
+    expect(exceptionEvent).toBeDefined();
+  });
+
+  it('truncates very long messages/labels', () => {
+    const ga = GA(config, 'v1', 'v1-long');
+    ga.init();
+
+    const longMsg = 'a'.repeat(1000);
+    const error = new Error(longMsg);
+    captureException(error);
+
+    const exceptionEvent = window.dataLayer.find(e => e[0] === 'event' && e[1] === 'exception');
+    expect(exceptionEvent[2].description.length).toBeLessThan(150);
+  });
+});