One way I found to handle it: to clear mock function after each test: To add to Sum.test.js: afterEach(() => { local.getData.mockClear(); }); If you’d like to clear all mock functions after each test, use clearAllMocks afterEach(() => { jest.clearAllMocks(); });
For particular spec file, Andreas’s is good enough. Below setup will suppress console.log statements for all test suites, jest –silent (or) To customize warn, info and debug you can use below setup tests/setup.js or jest-preload.js configured in setupFilesAfterEnv global.console = { …console, // uncomment to ignore a specific log level log: jest.fn(), debug: jest.fn(), info: … Read more
Use mockFn.mockImplementation(fn). import { funcToMock } from ‘./somewhere’; jest.mock(‘./somewhere’); beforeEach(() => { funcToMock.mockImplementation(() => { /* default implementation */ }); // (funcToMock as jest.Mock)… in TS }); test(‘case that needs a different implementation of funcToMock’, () => { funcToMock.mockImplementation(() => { /* implementation specific to this test */ }); // (funcToMock as jest.Mock)… in TS … Read more
Also using Babel, Typescript and Jest. Had the same failure, driving me crazy for hours. Ended up creating a new babel.config.js file specifically for the tests. Had a large .babelrc that wasn’t getting picked up by jest no matter what i did to it. Main app still uses the .babelrc as this overrides babel.config.js files. … Read more
In version 23.3.0 of jest, expect(string).toMatch(string) expects a string. Use: const expected = { name:’component name’ } const actual = { name: ‘component name’, type: ‘form’ } expect(actual).toMatchObject(expected) result is passing test
Great solution from @chiedo However, we use ES2015 syntax and I felt it was a little cleaner to write it this way. class LocalStorageMock { constructor() { this.store = {}; } clear() { this.store = {}; } getItem(key) { return this.store[key] || null; } setItem(key, value) { this.store[key] = String(value); } removeItem(key) { delete this.store[key]; … Read more
Jest suppresses the console log message by default. In order to show the console log message, set silent option to false at the command line set –silent=false in the command line: npm run test — –silent=false
As of Jest 22.0.0+, you can use the –clearCache option: Deletes the Jest cache directory and then exits without running tests. Will delete cacheDirectory if the option is passed, or Jest’s default cache directory.
When using Jest 21.2.1, I can see code coverage at the command line and create a coverage directory by passing –coverage to the Jest script. Below are some examples: I tend to install Jest locally, in which case the command might look like this: npx jest –coverage I assume (though haven’t confirmed), that this would … Read more
CLI options are documented and also accessible by running the command jest –help. You’ll see the option you are looking for : –runInBand.