how to reset module imported between tests
@ltamajs solution is great for require
but in the case you are using import
then you will receive the next error.
SyntaxError: /path/to/test/file.js: 'import' and 'export' may only appear at the top level
To solve this issue, you can use the babel-plugin-dynamic-import-node
plugin and then reset the modules. Overall, it looks like this:
describe('MyTests', () => {
let MyModule;
beforeEach(() => {
return import('../module/path').then(module => {
MyModule = module;
jest.resetModules();
});
});
test('should test my module', () => {
expect(MyModule.aMethod).not.toBeUndefined();
});
});
Source: https://github.com/facebook/jest/issues/3236#issuecomment-698271251
You have to re-import or re-require your module. Check the doc or this issue for more information:
https://github.com/facebook/jest/issues/3236
https://facebook.github.io/jest/docs/en/jest-object.html#jestresetmodules
describe('MyModule', () => {
beforeEach(() => {
jest.resetModules()
});
describe('init', () => {
const myModule = require('./MyModule');
it('not throws exception when called', () => {
expect(() => myModule.init()).not.toThrow();
});
})
describe('do', () => {
const myModule = require('./MyModule');
it('throw when not init', () => {
expect(() => myModule.do()).toThrow();
});
})
})