Angular 4单元测试遇ReferenceError: Can't find variable: Zone问题求助

Hey there, let's get that Zone error sorted out for your Angular 4 tests! Even though you have zone.js in your package.json, the issue is likely that your testing environment isn't loading the test-specific Zone.js bundle that Angular's TestBed depends on. Here's what to check:

1. Ensure your test entry file loads zone-testing #

First, open your test entry file (usually test.ts at the root of your project). Make sure you have this import at the top, before any other test-related imports:

import 'zone.js/dist/zone-testing';

If this line was commented out or missing, adding it will load the Zone.js build designed for testing, which provides the Zone variable PhantomJS is complaining about.

2. Verify Karma is including the zone-testing file #

Check your karma.conf.js file's files array. You need to explicitly include the zone-testing bundle so Karma serves it to PhantomJS. Add this entry if it's missing:

files: [
  // ... other existing files
  { pattern: './node_modules/zone.js/dist/zone-testing.js', watched: false }
]

The watched: false flag ensures Karma doesn't reload this file unnecessarily during test runs.

3. Match zone.js version to Angular 4 compatibility #

Angular 4 works best with zone.js versions around ~0.8.10 (your current 0.8.4 is a bit outdated). Try updating to a compatible version to avoid PhantomJS compatibility gaps:

npm install zone.js@~0.8.10 --save-dev

Quick tweak to your test code #

While the main issue is Zone loading, I noticed your beforeEach is missing a call to compileComponents() (this helps ensure async component compilation works correctly). For completeness, update it to:

beforeEach(async(() => {
  TestBed.configureTestingModule({
    // Add your component declarations/providers here as needed
  }).compileComponents();
}));

Once you make these changes, restart your test runner—PhantomJS should now find the Zone variable and your tests should proceed past this error!

内容的提问来源于stack exchange，提问作者user911