console.log statements output nothing at all in Jest. This was working for me yesterday, and all of sudden, it’s not working today. I have made zero changes to my config and haven’t installed any updates. I’m not using the –forceExit option. Still seeing this issue. 17 Answers 17
I have a mapModule where I import components and export them: import ComponentName from ‘../components/ComponentName’; export default { name: ComponentName, }; How can I test that mapModule has the correct exported keys, values and that they are not null or undefined? 6 Answers 6
I keep getting “localStorage is not defined” in Jest tests which makes sense but what are my options? Hitting brick walls. 25 Answers 25
Jest is picking up an old version of a package and thus my tests fail unless I use –no-cache. I can even delete the package folder from folder node_modules and Jest is happy to run the tests (almost all are passing). So how do I clear the Jest cache? 4 Answers 4
Is there a way to have code coverage in the JavaScript Jest testing framework, which is built on top of Jasmine? The internal framework does not print out the code coverage it gets. I’ve also tried using Istanbul, blanket, and JSCover, but none of them work. 11 Answers 11
I’m using moment.js to do most of my date logic in a helper file for my React components but I haven’t been able to figure out how to mock a date in Jest a la sinon.useFakeTimers(). The Jest docs only speak about timer functions like setTimeout, setInterval etc but don’t help with setting a date … Read more
I have an application that depends on environmental variables like: const APP_PORT = process.env.APP_PORT || 8080; And I would like to test that for example: APP_PORT can be set by a Node.js environment variable. or that an Express.js application is running on the port set with process.env.APP_PORT How can I achieve this with Jest? Can … Read more
I’m running Jest tests via npm test. Jest runs tests in parallel by default. Is there any way to make the tests run sequentially? I have some tests calling third-party code that relies on changing the current working directory. 11 Answers 11
I have a component library that I’m writing unit tests for using Jest and react-testing-library. Based on certain props or events I want to verify that certain elements aren’t being rendered. getByText, getByTestId, etc throw and error in react-testing-library if the element isn’t found causing the test to fail before the expect function fires. How … Read more
I’m writing an async test that expects the async function to throw like this: it(“expects to have failed”, async () => { let getBadResults = async () => { await failingAsyncTest() } expect(await getBadResults()).toThrow() }) But jest is just failing instead of passing the test: FAIL src/failing-test.spec.js ● expects to have failed Failed: I should … Read more
