warn when a propName looks like a mistyped event

[bloodyowl]

closes #3548

[zpao]

I think we probably want this in a __DEV__ block so we aren't doing extra startup work in prod (it might get dead code eliminated but not certain)

[zpao]

We'll need to rebase and fix a couple things but overall it seems fine to me. Any thoughts @spicyj?

[bloodyowl]

fixes added @zpao

[waldreiter]

This would for example not catch onMouseup. Maybe something like the following would be better?

var eventType = eventTypes[propName.toLowerCase()];
warning(
  !eventType || eventType === propName,

[bloodyowl]

good catch

how about building a regexp with the case insensitive flag when creating the map, and test anything matching the pattern, but not equal to the valid prop?

[bloodyowl]

and would fail with this edge-case:

var eventTypes = {}
var eventType = eventTypes["constructor"]
!eventType || eventType === "constructor" // false

[bloodyowl]

@zpao @cody this is fixed.

[sophiebits]

topLevelTypes is the wrong thing to look at here. It doesn't include custom React events like onMouseEnter and onMouseLeave. Instead, you want to look at the "registration names" gathered at the top of each event "plugin":

react/src/renderers/dom/client/eventPlugins/SimpleEventPlugin.js

Lines 37 to 43 in 8f96434

	var eventTypes = {
	blur: {
	phasedRegistrationNames: {
	bubbled: keyOf({onBlur: true}),
	captured: keyOf({onBlurCapture: true}),
	},
	},

These are collected in EventPluginRegistry:

https://github.com/facebook/react/blob/8f9643485d767e44af8a9c388601414a4dadf67e/src/renderers/shared/event/EventPluginRegistry.js

Hopefully that gives you some clues to go on. I also don't love that the warning logic for DOM properties

react/src/renderers/dom/shared/DOMPropertyOperations.js

Line 84 in 71afd5a

'Unknown DOM property %s. Did you mean %s?',

is in a totally different place. We should at least make the error messages a little more similar.

[sophiebits]

I think we're going to go with #5361.