Adds to hasClass the ability to search using regex expression

[stackchain]

When using a framework that injects JSS (decorators) like material-ui, it becomes complicated to deal with class searching.
There are some conditions, especially when dealing with transitions, when adding and removing a react component affects the UX. Ex. there is no fade-out animation when the component just vanishes away from the user screen.

{ show && <MyFadeOutComponent /> }

So one way to tackle this problem is to add and remove classes to the component, instead of rendering off the react component, when removing the class the transitions will work fine.

{ <MyFadeInAndFadeOutComponent className="hide" />

Testing this situation using decorators is tricky; You can export a version of the component before the injection as most people do in the storybook to show the correct propTypes, but sometimes it will require more work to be accomplished.

export const UndecoredMyComponent = MyComponent; export default withStyles(styles, { theme: true })(MyComponent);

Another approach: you can mock the decorator.

Therefore would be great to add to hasClass function the ability to search using a regex, it makes those conditions above easier to test.

// Should pass if is hiding the component (using class) expect(hasClassName(node, /(MyComponent)-(hide)-(\d+)/)).to.equal(true);

[ljharb]

Interesting idea! This seems reasonable to add.

[ljharb]

Thanks, looks great!