UNCHANGED doesn't equal UNCHANGED when I npm link a library which is using mobx

[capaj]

So I was having a fun afternoon trying to figure out why mu observable is being populated with an empty object instead of my value when I call set().

There is this UNCHANGED

mobx/src/types/observablevalue.ts

Line 36 in f944b54

export const UNCHANGED: IUNCHANGED = {}

which is being compared to a newValue here:

mobx/src/types/observablemap.ts

Lines 185 to 187 in f944b54

	newValue = (observable as any).prepareNewValue(newValue) as V
	if (newValue !== UNCHANGED) {
	const notifySpy = isSpyEnabled()

And in my case the prepareNewValue() indeed returned UNCHANGED, but it didn't equal even though my newValue was the same as current value.

Look:

I stored the other UNCHANGED on my window and that equaled.
The reason why it doesn't equal is that I used npm link to load up a different version of mobx. And since webpack then loads multiple modules of mobx, when you use a set from one on another it just does really weird stuff.

Worst thing is-not even a peer dependency helps.
@mweststrate wasn't there some kind of warning when you loaded up multiple mobx modules at once?

[mweststrate]

@capaj I think this one could be fixed by storing UNCHANGED on the global state object instead of having it as module constant. Note that it might not be the last of your issues though, and if you could prevent linking / multiple instances that would be better :)

[mweststrate]

Created fix, will be part of next version

[mweststrate]

Released in 4.7.0 / 5.7.0

[lock]

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