20: factorial digit sum

20_factorial_digit_sum/factorial_test.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"testing"
+)
+
+func Test_findFactorial(t *testing.T) {
+	tt := []struct {
+		name  string
+		input int
+		want  string
+	}{
+		{
+			"2",
+			2,
+			"2",
+		},
+		{
+			"4",
+			4,
+			"24",
+		},
+		{
+			"10",
+			10,
+			"3628800",
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := findFactorial(tc.input)
+			if got != tc.want {
+				t.Errorf("findFactorial=%v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func Test_sumDigits(t *testing.T) {
+	tt := []struct {
+		name  string
+		input string
+		want  int
+	}{
+		{
+			"no_text",
+			"",
+			0,
+		},
+		{
+			"1",
+			"1",
+			1,
+		},
+		{
+			"12345",
+			"12345",
+			15,
+		},
+		{
+			"3628800",
+			"3628800",
+			27,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := sumDigits(tc.input)
+			if got != tc.want {
+				t.Errorf("sumDigits = %d, want %d", got, tc.want)
+			}
+		})
+	}
+}