I learning jest, writing my first snapshot tests for components using react-native & expo. I can run the test without the Icon component from 'react-native-vector-icons/MaterialIcons' inside my component. However when I attempt to run a test with the aforementioned Icon component I get the following error:
ReferenceError: You are trying to `import` a file after the Jest environment has been torn down. at Object.get Text [as Text] (node_modules/react-native/Libraries/react-native/react-native-implementation.js:118:12) at Icon.render (node_modules/@expo/vector-icons/build/vendor/react-native-vector-icons/lib/create-icon-set.js:120:58) at finishClassComponent (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:7618:31) at updateClassComponent (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:7568:24) at beginWork (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:9043:16) Cannot log after tests are done. Did you forget to wait for something async in your test? Attempted to log "Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: object. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.Check the render method of `Icon`. in Icon (created by Icon) in Icon".My code for the test is as follows:
import React from 'react'import * as Icon from 'react-native-vector-icons/MaterialIcons'import renderer from 'react-test-renderer'it('Renders an icon', () => { const tree = renderer.create(<Icon.default size={20} color={ 'grey' } name={ true ? 'check-box' : 'check-box-outline-blank' } /> ).toJSON() expect(tree).toMatchSnapshot();})My jest configuration in package.json is like this:
"jest": {"preset": "jest-expo","transformIgnorePatterns": ["node_modules/(?!((jest-)?react-native|react-clone-referenced-element|expo(nent)?|@expo(nent)?/.*|react-navigation|react-native-vector-icons|@unimodules))" ],"testRegex": "(/__tests__/.*|(\\.|/)(test|spec))\\.(jsx?|tsx?)$","moduleFileExtensions": ["ts","tsx","js","jsx","json","android.ts","android.tsx" ] },The components function fine outside of tests.