turadg/lazyspec

Slack off and let code write your unit tests

LazySpec

Automatically generate minimal spec files for Javascript modules. Works well with Jest snapshots to make painless tests. For example, given a test file src/components/Button.jsx,

import React from 'react';

class Button extends React.Component {
  static propTypes = {
    level: React.PropTypes.oneOf([
      'primary', 'secondary', 'tertiary', 'quaternary', 'text', 'icon',
    ]),
    disabled: React.PropTypes.bool,
    label: React.PropTypes.string.isRequired,
    height: React.PropTypes.number,
    children: React.PropTypes.element.isRequired,
  };

  render() {
    return (
      <button disabled={this.props.disabled}>
        <b>{this.props.label}</b>
      </button>
    );
  }
}

export default Button;

it will generate src/components/__tests__/Button-test.js:

/* @lazyspec (remove to manage manually) */
/* eslint-disable */
import Button from '../Button.js';

import React from 'react';
import renderer from 'react-test-renderer';

describe('Button', () => {
  it('exists', () => {
    expect(Button).toBeTruthy();
  });

  it('renders', () => {
    const comp = <Button children="mockElement" label="mockString" />;
    const tree = renderer.create(comp).toJSON();
    expect(tree).toMatchSnapshot();
  });
});

Usage

npm install -g lazyspec
lazyspec path/to/fileOrDir

For every dir in the list, it will glob all the .js and .jsx .js and add them.

For each file, it will generate a spec and the __tests__ dir if necessary. So far it only supports the Jest style layout but PRs for other test runners and layouts are welcomed!

In dev you can do, ./src/cli.js path/to/fileOrDir.

Editor integration

• for Sublime Text, https://github.com/turadg/sublime-react-ide

Known Issues

• Custom proptypes are never interpreted as required (e.g. message: MessageInterfacePropType.isRequired)

• Fails when more than one component is exported from a module. react-docgen now has findAllExportedComponentDefinitions, but we don't use it because modules often export a HOC and its base component so it would be redundant. Eventually this tool could detect which is the HOC and omit it.