validators.isObject() uses unreliable toString global function

[corvidism]

Hi,

this is bug report is mostly a PSA because you've already fixed it in the current dev branch, but maybe I'll save someone some time:

The validation added in tough-cookie@4.1.0, specifically the isObject function, fails in an environment that overrides the global toString method - for example, in a Jest test running in the jsdom environment.

What happens

Trying to create a new jar with new CookieJar() throws error [object Object].

Why

When you adapted the validator functions from check-types, you didn't bring over the locally defined toString function. That's fine in theory, the global object has a toString method, but it breaks if something redefines it - for example the jsdom environment, which replaces the default node global with a mocked window, where the toString method always returns undefined.

Temporary fix

Before creating the jar, define window.toString again:

window.toString = Object.prototype.toString;

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The upcoming TS refactor should fix this - the new objectToString function uses uses Object.prototype.toString as expected) - but I'd be happy to submit a pull request. I mean. It's literally one line of code :D.

[colincasey]

Thanks for opening this issue and providing a temporary workaround for those who may be affected @corvidism ❤️

We'd gladly accept a PR fix for this. Most of our maintainer focus has been on preparing for the upcoming TS refactor so fixing this in 4.1.x is less of a priority at the moment.

[corvidism]

Great, I'll do that.