Test helpers break compatibility with bignumber.js in tests

[abcoathup]

PaulRBerg reports on Twitter that Test helpers break compatibility with bignumber.js in their tests
(all tests that had "should.be.bignumber.equal" broke)

https://twitter.com/PaulRBerg/status/1163017370434265090?s=20

[nventuro]

Our assertions use chai-bn, which works with bn.js, because that's the one that web3 1.0 uses, and the type that truffle v5.0 returns.

I'm not aware of current libraries/frameworks using bignumber.js, we should consider supporting this use case if these exist.

[nventuro]

@PaulRBerg I saw you mentioned you used bignumber.js as a direct dependency: is there a reason to not use bn.js (which is what web3js and truffle support)?

[PaulRBerg]

Well, it's just what I prefer to use. I find the API much better and more intuitive.

And I am aware of at least 2 other projects using bignumber.js instead of bn.js.