Show functions and not <Profiler/> with react 16.3

[lukeapage]

We haven't quite yet upgraded to react 16.4 and with 16.3 Profiler is not defined, meaning that any react nodes without a type (like a function) in shallow get serialized as <Profiler/>

Its not that important but I thought it could happen in the future, so I did a small refactor to not match undefined and undefined.

[ljharb]

Thanks - could you add a test case that would fail without your changes?

[ljharb]

i wonder if a simpler change, since this is the 16.3 adapter, would be to just delete the Profiler line?

[ljharb]

We'll also need the same change in the 16 adapter, since that still supports 16.0 - 16.4.

[ljharb]

hmm, we have an explicit test that covers function children showing up as [function]. Can you share your test case?

[lukeapage]

I'm a bit confused now.

1. The Profiler line is valid for 16.4, which I thought the 16.3 adapter supported?
2. I can do || NaN as a simpler change as per your commit, but then I may as well keep the code as-is - should I simplify it?

I don't have a (unit) test case at the moment but I can have a go at writing one once I understand what changes you want.

[ljharb]

@lukeapage the 16.3 adapter does not support 16.4, only the 16 adapter does. I've already pushed up commits that use || NaN.

Specifically I'm interested in reproducing:

meaning that any react nodes without a type (like a function) in shallow get serialized as

from your OP. Can you provide a case that does that in React 16.3?

[lukeapage]

I followed the instructions and I get errors running anything in enzyme

$ npm run env -- 16

> [email protected] env C:\git\enzyme
> babel-node ./env.js "16"

events.js:183
      throw er; // Unhandled 'error' event
      ^

Error: spawn npm ENOENT
    at _errnoException (util.js:992:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:190:19)
    at onErrorNT (internal/child_process.js:372:16)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] env: `babel-node ./env.js "16"`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] env script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

on node 8.11.4

[ljharb]

@lukeapage it's entirely possible that our dev scripts don't work on windows; could you share the code itself, and i can try to repro it?

[lukeapage]

I did add a unit test - it will fail because I don't know exactly what the function output is.

its a class that passes a function callback, shallow rendered and passed to jest's toMatchSnapshot

class B extends React.Component {
   render() {
       this.props.children();
   }
}
class A extends React.Component {
    render() {
       return <B>{() => <div/>}</B>;
    }
}

const wrapper = shallow(<A></A>);
expect(wrapper).toMatchSnapshot();

and its the snapshot serializer which uses the display name during serialization.

[ljharb]

Thanks, I'll give that a shot.

[ljharb]

What's the "snapshot serializer" here? enzyme doesn't have snapshot support - only .debug(), which i'd recommend instead - and it seems like your test case is passing just fine on master in React 16.3.

[ljharb]

I'm going to merge this, since i still think these are good fixes - but I'm pretty confident your issue is that you're relying on non-enzyme snapshotting. If you stick with .debug() output, you should be fine.