libs/mocha/should.js
function(expr, msg, negatedMsg, expected, showDiff){
        var msg = this.negate ? negatedMsg : msg
            , ok = this.negate ? !expr : expr
            , obj = this.obj;

        if (ok) return;

        var err = new AssertionError({
            message: msg.call(this)
            , actual: obj
            , expected: expected
            , stackStartFunction: this.assert
            , negated: this.negate
        });

        err.showDiff = showDiff;

        throw err;
    }
function(expr, msg, negatedMsg, expected, showDiff){
        var msg = this.negate ? negatedMsg : msg
            , ok = this.negate ? !expr : expr
            , obj = this.obj;

        if (ok) return;

        var err = new AssertionError({
            message: msg.call(this)
            , actual: obj
            , expected: expected
            , stackStartFunction: this.assert
            , negated: this.negate
        });

        err.showDiff = showDiff;

        throw err;
    }
function ( expr , msg , negatedMsg , expected , showDiff ) { var msg = this . negate ? negatedMsg : msg , ok = this . negate ? ! expr : expr , obj = this . obj ; if ( ok ) return ; var err = new AssertionError ( { message : msg . call ( this ) , actual : obj , expected : expected , stackStartFunction : this . assert , negated : this . negate } ) ; err . showDiff = showDiff ; throw err ; }
Assert _expr_ with the given _msg_ and _negatedMsg_.

@param {Boolean} expr
@param {String} msg
@param {String} negatedMsg
@param {Object} expected
@api private
Assert _expr_ with the given _msg_ and _negatedMsg_ .