My test doesn't seem to importing my manual mock under __mocks__/Auth.js.
I have a module that I use, Auth.js in my react application, App.js. I am trying to mock that module using a manual mock by making a mocked file under __mocks__/Auth.js. My __mocks__ is at the same file level as App.js and Auth.js.
I have a repo here: https://github.com/chaselw/reactTesting
Or my test is below:
import React from 'react';
import Enzyme, { shallow, mount } from 'enzyme';
import EnzymeAdapter from 'enzyme-adapter-react-16'
import App from './App';
Enzyme.configure({ adapter: new EnzymeAdapter() });
test('logged in false', () => {
jest.mock('./Auth.js'); //Trying to get `auth.isLoggedIn() === false`
const wrapper = mount(<App />);
console.log(wrapper.debug())
expect(wrapper.exists("[data-test='Logged-In-False']")).toBe(true);
})
Expected result is that the test would return a "Logged-In-False" div from Login module after the if check on auth.isLoggedIn(). However I get the "true" div back.
In the test if I do: console.log(wrapper.auth.isLoggedIn()), it returns .isLoggedIn() is undefined.
I am new to React, jest and enzyme. I have no idea what is wrong, any help would be great! Thanks.
The solution was simple. jest.mock('./Auth.js') needs to be not inside a test, but rather at the top level as the imports.
import React from 'react';
import Enzyme, { shallow, mount } from 'enzyme';
import EnzymeAdapter from 'enzyme-adapter-react-16'
import App from './App';
jest.mock('./Auth');
Enzyme.configure({ adapter: new EnzymeAdapter() });
test('logged in false', () => {
//Trying to get `auth.isLoggedIn() === false`
const wrapper = mount(<App />);
console.log(wrapper.debug())
expect(wrapper.exists("[data-test='Logged-In-False']")).toBe(true);
})
I am trying to test a component in react native, but it gets stuck on the shallow test. If I pass an incorrect component, the test fails, but if I pass a react-native text component it gets stuck.
import React from "react";
import Enzyme, {shallow, mount} from "enzyme";
import Screen from 'react-native-login'
import Adapter from "enzyme-adapter-react-16"
import { configure } from 'enzyme'
import {Text} from 'react-native'
configure({ adapter: new Adapter() })
test('render with react-native component', () => {
const wrapper = shallow(<Text />); // Hangs
})
I have tests for jest written in jsx files with these same lines of code:
import React from 'react';
import { configure } from 'enzyme';
import { shallow } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
configure({ adapter: new Adapter() });
How can I make a config file to include these every time instead of writing these in my test file?
You will still need to do
import React from 'react';
import { shallow } from 'enzyme';
in your unit tests since your tests need to use React and shallow but you can move
import { configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
configure({ adapter: new Adapter() });
into a separate file and configure that file to be run before each test.
If you bootstrapped your app using create-react-app v4 or higher and haven't ejected then you can put that code in src/setupTests.js
Otherwise you can configure Jest to run it as a setupTestFrameworkScriptFile
I created a new React application by create-react-app and I wanted to write a unit test to a component named "MessageBox" that I created in the application. This is the unit test that I wrote:
import MessageBox from "../MessageBox";
import { shallow } from 'enzyme';
import React from 'react';
test('message box', () => {
const app = {setState: jest.fn()};
const wrapper = shallow(<MessageBox app={app}/>);
wrapper.find('button').at(0).simulate('click');
expect(app.setState).toHaveBeenLastCalledWith({modalIsOpen: false});
});
I also added a file under 'src' folder named 'setupTests.js' with the content:
import * as enzyme from 'enzyme';
import * as Adapter from 'enzyme-adapter-react-16';
enzyme.configure({ adapter: new Adapter() });
I ran it by:
npm test
and I got the error:
Enzyme Internal Error: Enzyme expects an adapter to be configured, but
found none. To configure an adapter, you should call Enzyme.configure({ > adapter: new Adapter() })
Do you know what can solve this problem?
Add it to your test case file.
import React from 'react';
import Adapter from 'enzyme-adapter-react-16';
import { shallow, configure } from 'enzyme';
configure({adapter: new Adapter()});
test('message box', ()=> {
...
})
Also, if you don't want to import your setupTests.js file into every test file, you can place it in your package.json folder:
"jest": {
"setupTestFrameworkScriptFile": "./test/setupTests.js" }
Update:
Note: setupTestFrameworkScriptFile is deprecated in favor of setupFilesAfterEnv.
https://jestjs.io/docs/en/configuration
The file 'setupTests' has to be imported to the test file:
import MessageBox from "../MessageBox";
import { shallow } from 'enzyme';
import React from 'react';
import "../setupTests"
test('message box', ()=> {
...
})
As Priyank said, if you are using Create React App, it will pick up the configuration from src/setupTests.js.
Add:
import { configure } from 'enzyme'
import Adapter from 'enzyme-adapter-react-16'
configure({ adapter: new Adapter() })
A lot of answers are saying import setupTests.js into your test file. Or
configure enzyme adapter in each test file. Which does solve the immediate problem.
But long term, if you add a jest.config.js file to the project root. You can configure it to run a setup file on launch.
jest.config.js
module.exports = {
setupTestFrameworkScriptFile: "<rootDir>/src/setupTests.ts"
}
This tells Jest to run setupTest.ts every time it's launched.
This way if you need to add polyfills or add global mock like localstorage, you can add it to your setupTests file and its configured everywhere.
The Enzyme docs don't cover integration with Jest, so it is confusing to fuse these two together.
For me when using React with create-react-app I had to make sure the file name was correct. The file has to be src/setupTests.js with an s at the end of Tests.
Inside setupTests.js is the following:
import { configure } from "enzyme";
import Adapter from "enzyme-adapter-react-16";
configure({ adapter: new Adapter() });
When running npm run test it auto finds the setupTests.js file. There is no need to import it into each test file.
You need to use the import like this:
import Adapter from 'enzyme-adapter-react-16';
This way: (import * as Adapter from ...) returns a message "TypeError: Adapter is not a constructor."
Add import React from 'react'; to the top of your file.
You are using JSX syntax <MessageBox app={app}/>, which transpiles into React.createComponent(...). In order for this to work React variable must be defined in the scope of the file.
Try sth like this;
import React from 'react';
import App from './containers/App';
import enzyme from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
enzyme.configure({ adapter: new Adapter() });
describe('App Screen', () => {
let mountedAppScreen;
let props;
const appScreen = () => {
if (!mountedAppScreen) {
mountedAppScreen = enzyme.mount(
<App {...props} />
);
}
return mountedAppScreen;
}
it("it always renders div", () => {
const divs = appScreen().find("div");
expect(divs.length).toBeGreaterThanOrEqual(1);
});
});
Using the latest version of the libraries, I've faced the same error reported in every answer of this question. Error: TypeError: Adapter is not a constructor.
I've grouped all the necessary steps in order to proper test your ReactJS component using Enzyme (I've used Jest but it might work with Mocha as well, in that case, just switch the main test package):
1) Libraries (package.json):
"dependencies": {
"jest": "^24.6.0",
(...)
}
"devDependencies": {
"chai": "^4.2.0",
"enzyme": "^3.7.0",
"enzyme-adapter-react-16": "^1.7.0",
(...)
}
2) TEST SETUP: You can setup the Enzyme in every test. But as type_master_flash wisely suggested, you can add a script to do that. In order to do so, create a new setting in your package.json file at the same level of the sessions scripts, dependencies, etc:
Jest Version 23.x (or previous):
"devDependencies": {
(...)
},
"jest": {
"setupTestFrameworkScriptFile": "./tests.setup.js"
},
After Jest 24.0 version: According to Jest Documentation, "setupTestFrameworkScriptFile is deprecated in favor of setupFilesAfterEnv".
"devDependencies": {
(...)
},
"jest": {
"setupFilesAfterEnv": ["./tests.setup.js"]
},
This file can be anywhere you prefer and you can name it as you wish. Just remember to setup the proper file location. In the current example I've stored my file in the root of my project.
3) tests.setup.js: As I've discovered in Enzyme: TypeError: Adapter is not a constructor, the problem here is that we cannot "import '' a module with a default export". The proper way of configuring your file is:
import Enzyme from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
Enzyme.configure({ adapter: new Adapter() });
Just that and you are good to test your components.
Cheers and hope this helps.
For everyone who read this in the future, setupTestFrameworkScriptFile is deprecated in favor of setupFilesAfterEnv by the documentation, in new versions. We can add our file like this:
"setupFiles": [
"<rootDir>/src/setupTests.js"
]
I faced the same error and for some reason React wasn't picking up setupTests.js file automatically.
I created a new file called jest.config.js at the root directory and added
{ "jest": { "setupTestFrameworkScriptFile": "<rootDir>/path/to/your/file.js", } }
After this, error disappeared.
Note: Later on, I removed the jest.config.js file but it still works now.
Not sure what was actually causing the problem though!
The file configuration must be in setupFilesAfterEnv property of jest.config.js
{
...
setupFilesAfterEnv: ["<rootDir>/jest.transform.js"],
...
}
If anyone comes across this while trying to fix this after setting up Testing React Components with Jest in GatsbyJs (https://www.gatsbyjs.org/docs/testing-react-components/)
In the setup-test-env.js you make, edit it to look like this:
import "#testing-library/jest-dom/extend-expect"
import { configure } from 'enzyme'
import Adapter from 'enzyme-adapter-react-16'
configure({ adapter: new Adapter() })
Create a file named setupTests.js in the root of your project. jest will automatically look for this file before running any test suits. Add the following content to the file.
import Enzyme from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
Enzyme.configure({adapter:new Adapter()})
Note: the filename should be exactly the same.no need to import this setupTests.js file into your test files.it will work automatically
For those who use VS Code and the Jest Runner extension for a React CRA app, don't forget to configure Jest Runner to use CRA's built in script runner by setting the jest command to:
npm test -- --watchAll=false
You will get the error in topic if you forget to do that. And since you are using CRA you won't be able to configure setupFilesAfterEnv in package.json nor jest.config.js. Trying that will result in this error:
These options in your package.json Jest configuration are not currently supported by Create React App
npm i enzyme-adapter-react-16 enzyme-to-json --save-dev
Add to package.json
enter image description here
"jest": {
"collectCoverageFrom": [ "src/**/*.js", "!src/index.js" ]
};
Add two files to src folder ->
setupTests.js
tempPolyfills.js
setupTests.js :
import requestAnimationFrame from './tempPolyfills';
import { configure } from "enzyme";
import Adapter from 'enzyme-adapter-react-16';
configure({adapter: new Adapter(), disableLifecycleMethods:true});
tempPolyfills.js:
const requestAnimationFrame = global.requestAnimationFrame = callback => {
setTimeout(callback,0);
};
export default requestAnimationFrame;
in case shallow -> expect() fails in test case use toJson() :
Example :
import { shallow } from "enzyme";
import App from "./App";
import toJson from 'enzyme-to-json';
describe('App', () => {
const app = shallow(<App />);
it('renders correctly', () => {
expect(toJson(app)).toMatchSnapshot();
});
});
If you think you've otherwise setup everything correctly (e.g. have the #wojtekmaj/enzyme-adapter-react-17 for React 17 support installed), one more pitfall to check with Typescript:
Do you have
"esModuleInterop": true,
and the matching import format for the adapter?
import Adapter from '#wojtekmaj/enzyme-adapter-react-17';
import Enzyme from 'enzyme';
Hi I was trying to test the react application With enzyme, But it throws an error TypeError: Adapter is not a constructor , Any Idea
This is my test file
import ProductRow from '../product_row';
import React from 'react';
// import { mount } from 'enzyme';
import * as enzyme from 'enzyme';
import * as Adapter from 'enzyme-adapter-react-16';
enzyme.configure({ adapter: new Adapter() });
test('TodoComponent renders the text inside it', () => {
const wrapper = enzyme.mount(
<ProductRow item={{}} quickView={[]}
productPage={''}
count={0}
numberOfColumns={0}
title={'title'}
taxonomies={{}}
excerpt={'excerpt'}
/>
);
});
TypeError: Adapter is not a constructor
I don't think import * works as expected when importing a module with a default export, this should work:
import Enzyme from 'enzyme'
import Adapter from 'enzyme-adapter-react-16'
Enzyme.configure({ adapter: new Adapter() })
BTW. you can put the above in a file and reference it in your Jest settings so you don't have to add this to every test:
setupFiles: ['<rootDir>/tools/jest/setup-react-adapter.js'],
For TypeScript:
import { configure } from 'enzyme';
import * as ReactSixteenAdapter from 'enzyme-adapter-react-16';
const adapter = ReactSixteenAdapter as any;
configure({ adapter: new adapter.default() });
You need to use the import like this:
import Adapter from 'enzyme-adapter-react-16';
This way: (import * as Adapter from ...) returns a message "TypeError: Adapter is not a constructor."
In case you are using Typescript with the esModuleInterop option enabled, you'll need this:
import { configure} from 'enzyme';
import * as ReactSixteenAdapter from 'enzyme-adapter-react-16';
configure({ adapter: new (ReactSixteenAdapter as any)() });