EthWorks
bn-chai
bn-chai extends Chai with assertions about bn.js decimals.
Installation
npm install -s bn-chaiSetup
var chai = require('chai');
var BN = require('bn.js');
var bnChai = require('bn-chai');
chai.use(bnChai(BN));Usage
When comparing two bn.js decimals bn1 and bn2, instead of doing:
expect(bn1.eq(bn2)).to.be.true;You can do this instead:
expect(bn1).to.eq.BN(bn2);This plugin is also handy when comparing a bn.js decimal to an inline constant, so instead of writing:
expect(bn1.eq(new BN('1'))).to.be.true;You can simply write:
expect(bn1).to.eq.BN(1);Which is simpler and more readable.
Assertions
eq
Asserts that the target is equal to the given object.
expect(new BN('1')).to.eq.BN(1);
expect(new BN('1')).not.to.eq.BN(0);lt
Asserts that the target is less than the given object.
expect(new BN('0')).to.be.lt.BN(1);
expect(new BN('1')).not.to.be.lt.BN(1);lte
Asserts that the target is less than or equal to the given object.
expect(new BN('0')).to.be.lte.BN(1);
expect(new BN('1')).to.be.lte.BN(1);
expect(new BN('2')).not.to.be.lte.BN(1);gt
Asserts that the target is greater than the given object.
expect(new BN('1')).to.be.gt.BN(0);
expect(new BN('1')).not.to.be.gt.BN(1);gte
Asserts that the target is greater than or equal to the given object.
expect(new BN('1')).to.be.gte.BN(0);
expect(new BN('1')).to.be.gte.BN(1);
expect(new BN('1')).not.to.be.gte.BN(2);negative
Asserts that the target is negative.
expect(new BN('-1')).to.be.negative;
expect(new BN('1')).not.to.be.negative;even
Asserts that the target is even.
expect(new BN('2')).to.be.even;
expect(new BN('1')).not.to.be.even;odd
Asserts that the target is odd.
expect(new BN('1')).to.be.odd;
expect(new BN('2')).not.to.be.odd;zero
Asserts that the target is equal to 0.
expect(new BN('0')).to.be.zero;
expect(new BN('1')).not.to.be.zero;Mixing BN, numbers and strings
You can mix BN with numbers and strings freely:
expect(new BN('1')).to.eq.BN(new BN('1'));
expect(new BN('1')).to.eq.BN('1');
expect(new BN('1')).to.eq.BN(1);
expect('1').to.eq.BN(new BN('1'));
expect('1').to.eq.BN('1');
expect('1').to.eq.BN(1);
expect(1).to.eq.BN(new BN('1'));
expect(1).to.eq.BN('1');
expect(1).to.eq.BN(1);