Expression = require("../expression.js").Expression;

let six_plus_nine = new Expression('+', 6, 9);
let six_times_nine = new Expression('*', 6, 9);
let six_minus_nine = new Expression('-', 6, 9);
let sixteen_div_eight = new Expression('/', 16, 8);
let compound1 = new Expression('+', six_times_nine, six_plus_nine)
let compound2 = new Expression('*', six_times_nine, compound1)
let compound3 = new Expression('+', compound2, 3)

describe("constructor",
         function() { 
             let one = new Expression("+",0,1);
             it("not null", () => expect(one).not.toBe(null));
             it("op", () => expect(one.op).toBe("+"));
             it("left", () => expect(one.left).toBe(0));
             it("right", () => expect(one.right).toBe(1));
         });

describe("simple",
         function() {
             it("+", () => expect(six_plus_nine.eval()).toBe(15));
             it("-", () => expect(six_minus_nine.eval()).toBe(-3));
             it("*", () => expect(six_times_nine.eval()).toBe(54));
             it("/", () => expect(sixteen_div_eight.eval()).toBe(2));
         });

describe("compound",
         function() {
             it("1", () => expect(compound1.eval()).toBe(69));
             it("2", () => expect(compound2.eval()).toBe(3726));
             it("3", () => expect(compound3.eval()).toBe(3729));
         });
         
describe("floating point", //Testing floating point
         function() {
			 let addPointFive = new Expression("+", 0.5, 0.5)
			 let timesPointFive = new Expression("*", 0.5, 10)
			 let minusPointFive = new Expression("-", 10, 0.5)
			 let dividePointFive = new Expression("/", 0.5, 0.1)
			 
             it("+", () => expect(addPointFive.eval()).toBe(1.0));
             it("*", () => expect(timesPointFive.eval()).toBe(5.0));
             it("-", () => expect(minusPointFive.eval()).toBe(9.5));
             it("/", () => expect(dividePointFive.eval()).toBe(5.0));
         });         
         
         
describe("bad input", //Testing bad inputs
         function() {
			 let invalidStringLeft = new Expression("+", "five", 6)
			 let invalidStringRight = new Expression("+", 5, "six")
			 let invalidOperator = new Expression("^", 6, 9)
			 
             it("Invalid String on left side", () => expect(invalidStringLeft.eval()).toBe("Invalid number syntax"));
             it("Invalid String on right side", () => expect(invalidStringRight.eval()).toBe("Invalid number syntax"));
             it("invalid operator", () => expect(invalidOperator.eval()).toBe("Invalid operator syntax"));
         });
         
         
describe("compound bad input", //Testing bad inputs in compound cases
         function() {
			 let invalidNumber = new Expression("+", "five", 6)
			 let invalidOperator = new Expression("^", 6, 9)
			 
			 let semiValidCompound = new Expression("+", six_plus_nine, invalidNumber)
			 let completlyBadCompound = new Expression("+", invalidNumber, invalidOperator)
			 
             it("semi-valid",	() => expect(semiValidCompound.eval()).toBe("Invalid number syntax"));
             it("invalid",	() => expect(completlyBadCompound.eval()).toBe("Invalid number syntax")); //Expected to be invalid number because it is the first error to be encountered
         });