Add a Vector struct with Add and Sub methods along with tests

Author: Szymon Szeliga

.travis.yml

@@ -0,0 +1,4 @@
+language: go
+
+go:
+  - 1.6.1

main.go

@@ -1,7 +1,11 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+
+	"github.com/szeliga/goray/math"
+)
 
 func main() {
-	fmt.Println("Hello, World!")
+	fmt.Println(math.Vector{X: 1, Y: 1, Z: 1})
 }

math/vector.go

@@ -0,0 +1,18 @@
+package math
+
+// Vector - struct holding X Y Z values of a 3D vector
+type Vector struct {
+	X int
+	Y int
+	Z int
+}
+
+// Add - adds two vectors together
+func (a Vector) Add(b Vector) Vector {
+	return Vector{a.X + b.X, a.Y + b.Y, a.Z + b.Z}
+}
+
+// Sub - subtracts b Vector from a Vector
+func (a Vector) Sub(b Vector) Vector {
+	return Vector{a.X - b.X, a.Y - b.Y, a.Z - b.Z}
+}

math/vector_test.go

@@ -0,0 +1,17 @@
+package math
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAdd(t *testing.T) {
+	result := Vector{1, 1, 1}.Add(Vector{2, 2, 2})
+	assert.Equal(t, Vector{3, 3, 3}, result, "should add correctly")
+}
+
+func TestSub(t *testing.T) {
+	result := Vector{3, 3, 3}.Sub(Vector{1, 1, 1})
+	assert.Equal(t, Vector{2, 2, 2}, result, "should subtract correcly")
+}