arithmetic.js

describe('Arithmetic', function() {  
  describe('Validation', function() {
    it('rejects missing operation', function(done) {
      request.get('/arithmetic?operand1=21&operand2=21')
          .expect(400)
          .end(function(err, res) {
              expect(res.body).to.eql({ error: "Unspecified operation" });
              done();
          });
    });
    it('rejects invalid operation', function(done) {
      request.get('/arithmetic?operation=foobar&operand1=21&operand2=21')
          .expect(400)
          .end(function(err, res) {
              expect(res.body).to.eql({ error: "Invalid operation: foobar" });
              done();
          });
    });
    it('rejects missing operand1', function(done) {
      request.get('/arithmetic?operation=add&operand2=21')
          .expect(400)
          .end(function(err, res) {
              expect(res.body).to.eql({ error: "Invalid operand1: undefined" });
              done();
          });
    });
    it('rejects missing operand2', function(done) {
      request.get('/arithmetic?operation=add&operand1=21')
          .expect(400)
          .end(function(err, res) {
              expect(res.body).to.eql({ error: "Invalid operand2: undefined" });
              done();
          });
    });
    it('rejects operands with invalid sign', function(done) {
      request.get('/arithmetic?operation=add&operand1=4.2-1&operand2=4')
          .expect(400)
          .end(function(err, res) {
              expect(res.body).to.eql({ error: "Invalid operand1: 4.2-1" });
              done();
          });
    });
    it('rejects operands with invalid decimals', function(done) {
      request.get('/arithmetic?operation=add&operand1=4.2.1&operand2=4')
          .expect(400)
          .end(function(err, res) {
              expect(res.body).to.eql({ error: "Invalid operand1: 4.2.1" });
              done();
          });
    });
  });

  describe('Addition', function() {
    it('adds two positive integers', function(done) {
      request.get('/arithmetic?operation=add&operand1=21&operand2=21')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 42 });
              done();
          });
    });
    it('adds zero to an integer', function(done) {
      request.get('/arithmetic?operation=add&operand1=42&operand2=0')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 42 });
              done();
          });
    });
    it('adds a negative integer to a positive integer', function(done) {
      request.get('/arithmetic?operation=add&operand1=21&operand2=-42')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -21 });
              done();
          });
    });
    it('adds two negative integers', function(done) {
      request.get('/arithmetic?operation=add&operand1=-21&operand2=-21')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -42 });
              done();
          });
    });
    it('adds an integer to a floating point number', function(done) {
      request.get('/arithmetic?operation=add&operand1=2.5&operand2=-5')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -2.5 });
              done();
          });
    });
    it('adds with negative exponent', function(done) {
      request.get('/arithmetic?operation=add&operand1=1.2e-5&operand2=-1.2e-5')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0 });
              done();
          });
    });
  });

  describe('Subtraction', function() {
    it('subtracts two positive integers', function(done) {
      request.get('/arithmetic?operation=subtract&operand1=42&operand2=21')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 21 });
              done();
          });
    });
    it('subtracts an integer from itself', function(done) {
      request.get('/arithmetic?operation=subtract&operand1=42&operand2=42')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0 });
              done();
          });
    });
    it('subtracts a larger integer from another', function(done) {
      request.get('/arithmetic?operation=subtract&operand1=21&operand2=42')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -21 });
              done();
          });
    });
    it('subtracts a negative integer from a positive integer', function(done) {
      request.get('/arithmetic?operation=subtract&operand1=21&operand2=-21')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 42 });
              done();
          });
    });
    it('subtracts an integer from a floating point number', function(done) {
      request.get('/arithmetic?operation=add&operand1=-2.5&operand2=5')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 2.5 });
              done();
          });
    });
  });

  describe('Multiplication', function() {
    it('multiplies two positive integers', function(done) {
      request.get('/arithmetic?operation=multiply&operand1=21&operand2=2')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 42 });
              done();
          });
    });
    it('multiplies a positive integer with zero', function(done) {
      request.get('/arithmetic?operation=multiply&operand1=21&operand2=0')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0 });
              done();
          });
    });
    it('multiplies a positive integer and negative integer', function(done) {
      request.get('/arithmetic?operation=multiply&operand1=21&operand2=-2')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -42 });
              done();
          });
    });
    it('multiplies two negative integers', function(done) {
      request.get('/arithmetic?operation=multiply&operand1=-21&operand2=-2')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 42 });
              done();
          });
    });
    it('multiplies two floating point numbers', function(done) {
      request.get('/arithmetic?operation=multiply&operand1=.5&operand2=0.5')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0.25 });
              done();
          });
    });
    it('multiplies supporting exponential notation', function(done) {
      request.get('/arithmetic?operation=multiply&operand1=4.2e1&operand2=1e0')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 42 });
              done();
          });
    });
  });

  describe('Division', function() {
    it('divides a positive integer by an integer factor ', function(done) {
      request.get('/arithmetic?operation=divide&operand1=42&operand2=2')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 21 });
              done();
          });
    });
    it('divides a negative integer by an integer factor ', function(done) {
      request.get('/arithmetic?operation=divide&operand1=-42&operand2=2')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -21 });
              done();
          });
    });
    it('divides a positive integer by a non-factor', function(done) {
      request.get('/arithmetic?operation=divide&operand1=21&operand2=42')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0.5 });
              done();
          });
    });
    it('divides a positive integer by a negative integer', function(done) {
      request.get('/arithmetic?operation=divide&operand1=21&operand2=-42')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: -0.5 });
              done();
          });
    });
    it('divides zero by a positive integer', function(done) {
      request.get('/arithmetic?operation=divide&operand1=0&operand2=42')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0 });
              done();
          });
    });
    it('divides by zero', function(done) {
      request.get('/arithmetic?operation=divide&operand1=0.5&operand2=2')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: 0.25 });
              done();
          });
    });
    it('divides by zero', function(done) {
      request.get('/arithmetic?operation=divide&operand1=21&operand2=0')
          .expect(200)
          .end(function(err, res) {
              expect(res.body).to.eql({ result: null });
              done();
          });
    });
  });
});