react-component-isolator

A simple module that spins up a react app where the only component is the react component you pass in.

Set up:

Install react-component-isolator

npm install react-component-isolator --save-dev

Install react-app-rewired in the client

cd <REACT_SUBDIR>
npm install --save-dev react-app-rewired

Add an npm run isolate command

Inside your package.json in your React client, add a new script:

{
    "scripts": {
        "isolate": "react-app-rewired start"
    }
}

Ignore test files

Ignore the following folder:

<REACT_SUBDIR>/src/_isolator_generated_files_

Ignore the following file:

<REACT_SUBDIR>/config-overrides.js

Customization:

Project Subdirectory

If your React project is not in the /client folder, add a REACT_SUBDIR environment variable when running tests. If the top-level folder is the React project, use . as the subdirectory.

Writing Tests

We will assume that you are using dce-selenium to write your tests.

Import at the top of every test file:

const isolate = require('react-component-isolator');

Test an individual component:

Call the isolate function with an arguments object that has the following properties:

• component – the relative path of the component to test from within the /src folder
• test – an asynchronous function containing the tests to run on the component. Called with a url argument (the url to visit to view the component
• [props] – an object containing all the properties of the component in the form { prop: value } where the values must either be functions or JSONifiable values

From within a prop that is a function, you can use this.get(key) and this.set(key, val) to read from/write to the embeddedMetadata.

Using dce-selenium, you can get the embeddedMetadata using:

const data = await driver.getEmbeddedMetadata();

Example test:

it('Works', async function () {
    await isolate({
        component: 'Buttons/OkayButton',
        props: {
            title: 'Click Me',
            onClick: () => {
                this.set('buttonClicked', true);
            },
        },
        test: async (url) => {
            await driver.visit(url);
            await driver.clickByContents('Click Me');
            const data = await driver.getEmbeddedMetadata();
            assert(data.buttonClicked);
        },
    });
});