Add .isWeakRef()

[bigbigDreamer]

@sindresorhus done other PR to replace #164

[sindresorhus]

Tests are failing

[bigbigDreamer]

Tests are failing

Sorry, I haven't checked the problem yet. At present, it seems that only node version 14 is passed.

[bigbigDreamer]

Tests are failing

I found the reason, because JSDOM WeakRef currently supports V14.6.0+ , can I Mock one manually? As a downgrade solution to handle Node versions？

[bigbigDreamer]

Unfortunately, I have not found a solution on how to simulate the behavior of WeakRef. At present, because JSOM simulation is limited to Node V14.6.0+, the test of the lower version fails, so I can only temporarily close this PR, thank you for your understanding

[bigbigDreamer]

https://github.com/ungap/weakrefs/blob/master/cjs/index.js perhaps it can try mock in node env

[bigbigDreamer]

Although the use case must be run on a low version node environment, the minimum requirement for WeakRef is Node V14.6.0, so I don't think it is necessary to create a mock use case for it on a low version Node.

[bigbigDreamer]

Record: JSDOM@latest will reported error in ci with Node V10.

[bigbigDreamer]

Tests all pass, @sindresorhus 🥳

[sindresorhus]

Can you fix the merge conflict?

[bigbigDreamer]

Can you fix the merge conflict?

Ok. Had fixed！But I encountered a very strange problem. Line 343 is a blank line, but lint reported an error. I repeatedly checked the code and found no problems. Can I ask for your help.

[sindresorhus]

I suggest we just embed the WeakRef type so we don't have to require a higher target.

interface WeakRef<T extends object> {
    readonly [Symbol.toStringTag]: "WeakRef";

    /**
     * Returns the WeakRef instance's target object, or undefined if the target object has been
     * reclaimed.
     */
    deref(): T | undefined;
}

[bigbigDreamer]

I suggest we just embed the WeakRef type so we don't have to require a higher target.

interface WeakRef<T extends object> {
    readonly [Symbol.toStringTag]: "WeakRef";

    /**
     * Returns the WeakRef instance's target object, or undefined if the target object has been
     * reclaimed.
     */
    deref(): T | undefined;
}

done

[bigbigDreamer]

Can you fix the merge conflict?

Ok. Had fixed！But I encountered a very strange problem. Line 343 is a blank line, but lint reported an error. I repeatedly checked the code and found no problems. Can I ask for your help.

Thank you so much, I just noticed that I read the wrong file, it is a lint problem in another file, sorry, sorry for the trouble, I will be more careful next time