Node-Jasmine setup using module.exports

geom.js

function Rectangle(length, width) {
    this.length = length;
    this.width = width;
    this.isSquare = function function_name(argument) {
        return this.length === this.width;
    };
    this.area = function function_name(argument) {
        return this.length * this.width;
    };
    this.perimeter = function function_name(argument) {
        return (this.length * 2) + (this.width * 2);
    };
}
function Triangle(sideA, sideB, sideC) {
    this.sideA = sideA;
    this.sideB = sideB;
    this.sideC = sideC;
}
function LineSegment(x1, y1, x2, y2) {
    this.x1 = x1;
    this.y1 = y1;
    this.x2 = x2;
    this.y2 = y2;
    
    this.length = function(x1, y1, x2, y2) {
        xDistance = this.x2 - this.x1;
        yDistance = this.y2 - this.y1;
        return Math.sqrt(Math.pow(xDistance, 2) + Math.pow(yDistance, 2));
    };
}
module.exports = {
    rectangle: Rectangle,
    triangle: Triangle,
    lineSegment: LineSegment
};

geomSpec.js

var geometry = require('../geom');

describe("Rectangle tests", function() {
    it("should be square for a 1x1 rectangle", function() {
       var rect = new geometry.rectangle(1,1);
       var result = rect.isSquare();
       expect(result).toBe(true);
    });
    it("should NOT be square for a 1x2 rectangle", function() {
       var rect = new geometry.rectangle(1,2);
       var result = rect.isSquare();
       expect(result).toBe(false);
    });
    it("should have a perimeter of 4 for a 1x1 rectangle", function() {
       var rect = new geometry.rectangle(1,1);
       var result = rect.perimeter();
       expect(result).toBe(4);
    });
    it("should have a area of 100 for a 10x10 rectangle", function() {
       var rect = new geometry.rectangle(10,10);
       var result = rect.area();
       expect(result).toBe(100);
    });
});

describe("Line segments tests", function() {
    it("should return line length 1 for a 0,0 to 0,1 line", function() {
        var line = new geometry.lineSegment(0,0,0,1);
        var result = line.length();
        expect(result).toBe(1);
    });
    it("should return line length 0 for a 0,1 to 0,1 line", function() {
        var line = new geometry.lineSegment(0,1,0,1);
        var result = line.length();
        expect(result).toBe(0);
    });
    it("should return line length 0 for a 0,0 to 3,2 line", function() {
        var line = new geometry.lineSegment(0,0,3,2);
        var result = line.length();
        expect(result).toBe(3.605551275463989);
    });
});