Separate the GenerateRandomAlphaOnlyString function from stringutils

Signed-off-by: chaowang <chaowang@localhost.localdomain>
Upstream-commit: 7c35a2418265336a572976e2ced378ef4b6f1666
Component: engine

components/engine/internal/testutil/stringutils.go

@@ -0,0 +1,14 @@
+package testutil
+
+import "math/rand"
+
+// GenerateRandomAlphaOnlyString generates an alphabetical random string with length n.
+func GenerateRandomAlphaOnlyString(n int) string {
+	// make a really long string
+	letters := []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = letters[rand.Intn(len(letters))]
+	}
+	return string(b)
+}