IE9: Unable to call apply on console.error when encountering an unknown tag

[nhunzaker]

This was introduced in React 16.5.0.

If IE9 encounters an unknown html element in development, React crashes as it attempts to call console.error.apply here:

react/packages/shared/warningWithoutStack.js

Line 30 in b87aabd

console.error('Warning: ' + format, ...stringArgs);

This is reproduceable with the following CodePen:

Code
https://codepen.io/nhunzaker/pen/YOeZXv

Demo
https://s.codepen.io/nhunzaker/debug/YOeZXv/mWMoNxzPjbZk

[gaearon]

What's the error?

[nhunzaker]

The spread operator turns into apply like so:

// Before: console.error('Warning: ' + format, ...stringArgs);
console.error.apply(console, ['Warning' + format].concat(stringArgs))

IE9 doesn't support apply on console.error:

[link-alex]

I can try to check this one as "good first issue" if you don't mind :)

[gaearon]

Should be fixed in 16.5.1