feat(schema): testing utilities (#20705)

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

schema/testing/enum_test.go

@@ -0,0 +1,15 @@
+package schematesting
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"pgregory.net/rapid"
+)
+
+func TestEnumType(t *testing.T) {
+	rapid.Check(t, func(t *rapid.T) {
+		enumType := EnumType.Draw(t, "enum")
+		require.NoError(t, enumType.Validate())
+	})
+}