matrix is done

Signed-off-by: Casey Lee <cplee@nektos.com>

pkg/common/cartesian.go

@@ -0,0 +1,54 @@
+package common
+
+// CartesianProduct takes map of lists and returns list of unique tuples
+func CartesianProduct(mapOfLists map[string][]interface{}) []map[string]interface{} {
+	listNames := make([]string, 0)
+	lists := make([][]interface{}, 0)
+	for k, v := range mapOfLists {
+		listNames = append(listNames, k)
+		lists = append(lists, v)
+	}
+
+	listCart := cartN(lists...)
+
+	rtn := make([]map[string]interface{}, 0)
+	for _, list := range listCart {
+		vMap := make(map[string]interface{})
+		for i, v := range list {
+			vMap[listNames[i]] = v
+		}
+		rtn = append(rtn, vMap)
+	}
+	return rtn
+}
+
+func cartN(a ...[]interface{}) [][]interface{} {
+	c := 1
+	for _, a := range a {
+		c *= len(a)
+	}
+	if c == 0 {
+		return nil
+	}
+	p := make([][]interface{}, c)
+	b := make([]interface{}, c*len(a))
+	n := make([]int, len(a))
+	s := 0
+	for i := range p {
+		e := s + len(a)
+		pi := b[s:e]
+		p[i] = pi
+		s = e
+		for j, n := range n {
+			pi[j] = a[j][n]
+		}
+		for j := len(n) - 1; j >= 0; j-- {
+			n[j]++
+			if n[j] < len(a[j]) {
+				break
+			}
+			n[j] = 0
+		}
+	}
+	return p
+}

pkg/common/cartesian_test.go

@@ -0,0 +1,28 @@
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCartisianProduct(t *testing.T) {
+	assert := assert.New(t)
+	input := map[string][]interface{}{
+		"foo": []interface{}{1, 2, 3, 4},
+		"bar": []interface{}{"a", "b", "c"},
+		"baz": []interface{}{false, true},
+	}
+
+	output := CartesianProduct(input)
+	assert.Len(output, 24)
+
+	for _, v := range output {
+		assert.Len(v, 3)
+
+		assert.Contains(v, "foo")
+		assert.Contains(v, "bar")
+		assert.Contains(v, "baz")
+	}
+
+}