Allow Object.create(null) in no-mutating-assign

[macklinu]

Sometimes I see Object.create(null) as a first argument of Object.assign(), like in eslint-plugin-jest's codebase. Thoughts on including it as an acceptable first argument in the no-mutating-assign rule?

[jfmengels]

I don't see why not 👍
That said, I'm sure there are plenty of functions that create a new value (_.cloneDeep(), sometimes a.map(), etc.) that we may want to add as exceptions at some point, which may be hard to maintain, but I don't mind adding this.

I think any call to Object.create(xyz) should be allowed, regardless of the argument, as I don't think it mutates anything and always creates a new object

[jfmengels]

Could you add the following tests?
Valid:

• 'Object.assign(Object.create(a))' // Any call of Object.create should probably be allowed

Invalid:

• 'Object.assign(Object.create)' // We don't want to mutate the function

[graingert]

assigning to Object.create(v) can have side effects and mutate things: https://runkit.com/graingert/mutate

[jfmengels]

Ah, you're right. Scrap the valid test I proposed then

[macklinu]

Pushed up the invalid test case, @jfmengels 👍