addChainableMethod (ctx, name, method, chainingBehavior)
Adds a method to an object, such that the method can also be chained.
utils.addChainableMethod(chai.Assertion.prototype, 'foo', function (str) {
var obj = utils.flag(this, 'object');
new chai.Assertion(obj).to.be.equal(str);
});Can also be accessed directly from chai.Assertion.
chai.Assertion.addChainableMethod('foo', fn, chainingBehavior);The result can then be used as both a method assertion, executing both method and
chainingBehavior, or as a language chain, which only executes chainingBehavior.
expect(fooStr).to.be.foo('bar');
expect(fooStr).to.be.foo.equal('foo');