/react-remock

Get any Component replaced. Anywhere. 🛠♻️

Primary LanguageTypeScriptMIT LicenseMIT

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JFYI: You can mock any React Component, rendered anywhere, and for the any reason.

This is like proxyquire, or jest.mock. Not for node.js, but for React. Pure React Dependency Injection.

Every time you can NOT "story" something due to complexity. Every time you can NOT "enzyme" something, cos something deeply inside is "too smart" (and you can't use shallow). Every that time – mock the things you can NOT control.

                     /$$      /$$                     /$$      
                    | $$$    /$$$                    | $$      
  /$$$$$$   /$$$$$$ | $$$$  /$$$$  /$$$$$$   /$$$$$$$| $$   /$$
 /$$__  $$ /$$__  $$| $$ $$/$$ $$ /$$__  $$ /$$_____/| $$  /$$/
| $$  \__/| $$$$$$$$| $$  $$$| $$| $$  \ $$| $$      | $$$$$$/ 
| $$      | $$_____/| $$\  $ | $$| $$  | $$| $$      | $$_  $$ 
| $$      |  $$$$$$$| $$ \/  | $$|  $$$$$$/|  $$$$$$$| $$ \  $$
|__/       \_______/|__/     |__/ \______/  \_______/|__/  \__/

Remock is based on the same technique, as React-Hot-Loader - intercepts React calls and do.. what ever you want.

Use cases

This library was create for testing purposes only.

  • Using remock with enzyme testing allows you to perform more shallow mount testing. You can just mock out, complitely remove some (deep nested internal) Component which could make testing harder. For example - Redux Connect, always seeking proper Provider.

  • Using remock with storybooks testing allows you to hide some parts of "bigger", stories, leaving a holes in the story plot.

    • In case you are using BEM notation - it is really super easy to cat a hole, as long dimensions are propertly of a block, not element.
    • Yet again, in case of redux - you can replace connect by another component, to make it easier to provide mocked data for the story.

API

Play in codesandbox - https://codesandbox.io/s/xk7vp60o4

Api is simple - it gets React.createElement as an input and returns React.createElement as an output. And it will be called when real React.createElement has been called.

If you will not return anything - element willbe completely mocked. In other cases - you could specify what to return.

 import {remock} from 'react-remock';

 remock.mock('ComponentName'); // you can mock by name
 remock.mock(/Connect\((.*)\)/); // you can mock by RegExp
 
 remock.mock(ComponentClass); // you can mock by class
 
 remock.match((type, props, children) => true); // you can mock using user-defined function
 
 remock.mock(Component, (type, props, children) => ({type?, props?, children?})); // you can alter rendering
 
 remock.unmock('ComponentName' | ComponentName);
 
 // and dont forget to
 remock.clearMock();
 
 
 // You can also use "declarative" React API. (only with mount!)
 mount(
   <div>
       <Remocking component="Red">
       <Red />
   </div>
 );

More examples

// change prop on Hello
remock.mock(Hello, () => ({props:{name:"Remock"}}))

// change h2 to h3, change style, change children
remock.mock('h2', (type, props, children) => { 
  return ({
  type: 'h4',
  props: {
    ...props,
    style: {color:'#700'},   
  },
  children: `🧙️ ${children} 🛠`
})})

// wrap divs with a border
remock.mock('div', (type, props) => ({
  props: {
    ...props,
    style:{
      ...props.style,
      border:'1px solid #000'
    },
  }
}));

See also

Remock is a little brother of rewiremock

Licence

MIT

Happy mocking!