Prime factors

prime_factors/prime_factors_test.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestPrimeFactorsOf(t *testing.T) {
+	tt := []struct {
+		name  string
+		input int
+		want  []int
+	}{
+		{
+			"prime factors of 1",
+			1,
+			[]int{},
+		},
+		{
+			"prime factors of 2",
+			2,
+			[]int{2},
+		},
+		{
+			"prime factors of 3",
+			3,
+			[]int{3},
+		},
+		{
+			"prime factors of 1",
+			1,
+			[]int{},
+		},
+		{
+			"prime factors of 2",
+			2,
+			[]int{2},
+		},
+		{
+			"prime factors of 4",
+			4,
+			[]int{2, 2},
+		},
+		{
+			"prime factors of 5",
+			5,
+			[]int{5},
+		},
+		{
+			"prime factors of 6",
+			6,
+			[]int{2, 3},
+		},
+		{
+			"prime factors of 7",
+			7,
+			[]int{7},
+		},
+		{
+			"prime factors of 8",
+			8,
+			[]int{2, 2, 2},
+		},
+		{
+			"prime factors of 9",
+			9,
+			[]int{3, 3},
+		},
+		{
+			"prime factors of a big number",
+			2 * 2 * 2 * 3 * 3 * 5 * 7 * 11 * 13 * 73,
+			[]int{2, 2, 2, 3, 3, 5, 7, 11, 13, 73},
+		},
+	}
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := PrimeFactorsOf(tc.input)
+			if !reflect.DeepEqual(got, tc.want) {
+				t.Errorf("PrimeFactorsOf %d, got %v, want %v", tc.input, got, tc.want)
+			}
+		})
+	}
+}