JS snippet to handle JSON.stringify bug with BigInt builtins

[Blind4Basics]

see here

[hobovsky]

Quoting the original post:

One problem with BigInt is that JSON.stringify doesn't support it. Failure messages will throw a TypeError.

To make them look like this:

expected { BigInt: '123252' } to equal { BigInt: '123251' }

insert these two lines in Preloaded:

Object.defineProperty( BigInt.prototype, "toJSON", { value: String } );
Object.defineProperty( BigInt.prototype, "BigInt", { get() { return String(this); }, enumerable: true } ) ;

With that, you can use assert.strictEqual normally.

( I just now figured this out. In my own kata, I used to use something much more involved. )

Exception thrown:

TypeError: Do not know how to serialize a BigInt
    at JSON.stringify (<anonymous>)
    at processImmediate (internal/timers.js:461:21)

[hobovsky]

It seems this error has been fixed in Mocha a couple of days ago: mochajs/mocha#4112

@kazk do you think the snippet proposed in the initial post would be useful, or it would be possible to update Mocha?

[kazk]

It's possible to update Mocha for Node v12 when it's released, as long as it's Mocha v8.x (no breaking change) or if we're sure any breaking changes won't affect Codewars and Qualified users.

[hobovsky]

It just got released: https://github.com/mochajs/mocha/releases/tag/v8.3.0

Should I create an issue in runner repo for update of Mocha?

[kazk]

Yeah, I'll try to update soon, but having an issue for it is a good idea.

[hobovsky]

Workaround is no longer needed as the issue got fixed directly in Chai: codewars/runner#146