Move code out of cmd

day2/digits_test.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_digits_number(t *testing.T) {
+	tests := []struct {
+		n uint
+		d []uint8
+	}{
+		{n: 0, d: []uint8{0}},
+		{n: 1234, d: []uint8{4, 3, 2, 1}},
+		{n: 12345, d: []uint8{5, 4, 3, 2, 1}},
+	}
+	for _, tt := range tests {
+		name := strconv.FormatUint(uint64(tt.n), 10)
+		t.Run(name, func(t *testing.T) {
+			t.Run("digits", func(t *testing.T) {
+				assert.Equal(t, tt.d, digits(tt.n))
+			})
+			t.Run("number", func(t *testing.T) {
+				assert.Equal(t, tt.n, number(tt.d))
+			})
+		})
+	}
+}