Complete React 16 support

[ljharb]

Overarching project: https://github.com/airbnb/enzyme/projects/4

• Error Boundaries
  • componentDidCatch
    • Enzyme 3 couldn't test component when ComponentDidCatch happend #1255
  • Improve filenames in stack (Improve display of filenames in component stack facebook/react#12059)
  • getDerivedStateFromError (Support getDerivedStateFromError #2036)
• Portals
  • React adapter 16: portals and roots may render fragments #1710
  • Support of shallow for React16 Portals #1507
  • Support Portal components #252
• React.Fragment
  • Using <React.Fragment> prints warning with enzyme's mount with IE11 #1503
  • Adding Fragment support for shallow .find and .findWhere #1733
  • Enzyme matchers do not match correctly children of React Fragments #1799
• Rendering non-jsx
  • [Improved Fiber Support] Support Array-rendering components #1149
  • html() does not work on React components which return an array of elements #1178
  • React 16 fragments (rendering arrays and strings) unsupported #1213
  • Fix ShallowWrapper for array-rendering components #1498
• General issues around our use of private APIs
  • React toTree() handling mismatches #1512
• New context APIs in 16.3
  • New React context API adds new tag types #1509
  • Add support for react context element types, fixes #1509 #1513
  • dive() breaks when using the new context API. #1647
  • Invalid propType warning when rendering a Provider with no surrounding elements #1737
  • Dive shallow in a Context Consumer #1908
  • contextType (16.6) (wrappedComponent doesn't actually pass context values down in tests #2189, upstream PR)
  • better support for render props (Add renderProp to ShallowWrapper #1863)
• forwardRef
  • forwardRef: Enzyme Internal Error: unknown node with tag 14 #1604
  • Forward ref #1592
  • displayName set on forwardRef is not honored #1810 / [enzyme-adapter-react-{16,16.3}] [fix] forwardRef: respect .displayName #1817
• createRef
  • Using React 16 createRef #1704
• <React.StrictMode />: https://reactjs.org/docs/strict-mode.html
  • include mode in component stack (Include Modes in the component stack facebook/react#13240)
• <React.unstable_AsyncMode /> / <React.unstable_ConcurrentMode />:
• lazy/Suspense (16.6, Support Suspense #1917)
• memo (16.6, New memo feature from React 16.6 is not supported #1875)
• hooks (16.8, Testing Hooks with shallow: Invariant Violation #1938)
• Profiler (support unstable_Profiler #2054, fix: add Profiler support for adapter-react-16 #2233)

[MarcoNicolodi]

Isnt #1229 related to this?

[ljharb]

@MarcoNicolodi I don't think it is; that issue might either be a bug in v3 or intended behavior, but it's not related to React 16 specifically.

[petegleeson]

@ljharb I have verified that #1592 solves the forwardRef problem.

What is the release plan for these fixes? New versions for each feature or one release when all of these are completed?

Please let me know if there is anything I can do to help out.

[ljharb]

I’m hoping to bunch together as many as possible; there’s currently a backlog for me to go through, after which i hope to cut a release.

[ghost]

@ljharb is there a list of issues you'd like to get merged before releasing a new version on npm? Would love to see this one get released soon: #1513 as my team has already migrated our codebase so just waiting on tests passing.

Perhaps we could help finish up some issues for you to get the release in.

[simonbuchan]

Nope, just #1504 - createRef() works fine when it's nested. What about createRef()? I'm hitting that not working in styled-components/styled-components#1720 - even with just pure react + enzyme. Here's the test copied over:

test('enzyme should mount object refs', () => {
  const ref = React.createRef()
  const wrapper = mount(<div ref={ref} />)
  const div = wrapper.find('div').first()
  expect(div).toBeTruthy()
  expect(ref).toHaveProperty('current', div.instance())
})

Is this just a dumb mistake I'm making?

[nemoDreamer]

Is there any chance of an alpha release, or do all features need to be supported in one go?

[holsted]

It looks like the Profiler tickbox is still unsupported but the linked issue is closed. Are there plans to add support for this?

I ended up opening a PR for this.