Add tests

internal/rand/rand_test.go

@@ -0,0 +1,55 @@
+package rand
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRandomString(t *testing.T) {
+	s1, err := RandomString(42, AlphaNumericCharset)
+	require.NoError(t, err)
+
+	s2, err := RandomString(42, AlphaNumericCharset)
+	require.NoError(t, err)
+
+	require.NotEqual(t, s1, s2)
+}
+
+func TestUint32(t *testing.T) {
+	u1, err := Uint32()
+	require.NoError(t, err)
+
+	u2, err := Uint32()
+	require.NoError(t, err)
+
+	require.NotEqual(t, u1, u2)
+}
+
+func TestInt63(t *testing.T) {
+	u1, err := Int63()
+	require.NoError(t, err)
+
+	u2, err := Int63()
+	require.NoError(t, err)
+
+	require.NotEqual(t, u1, u2)
+}
+
+func TestInt63n(t *testing.T) {
+	u1, err := Int63n(42)
+	require.NoError(t, err)
+
+	u2, err := Int63n(42)
+	require.NoError(t, err)
+
+	require.NotEqual(t, u1, u2)
+
+	u3, err := Int63n(64)
+	require.NoError(t, err)
+
+	u4, err := Int63n(64)
+	require.NoError(t, err)
+
+	require.NotEqual(t, u3, u4)
+}