Update src/functions/projectConfig.ts

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: taeold

src/functions/projectConfig.ts

@@ -44,11 +44,11 @@ export function validatePrefix(prefix: string): void {
   if (prefix.length > 30) {
     throw new FirebaseError("Invalid prefix. Prefix must be 30 characters or less.");
   }
-  if (!/^[a-z0-9-]+$/.test(prefix)) {
-    throw new FirebaseError(
-      "Invalid prefix. Prefix can contain only lowercase letters, numeric characters, and dashes.",
-    );
-  }
+if (!/^[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/.test(prefix)) {
+  throw new FirebaseError(
+    "Invalid prefix. Prefix can contain only lowercase letters, numeric characters, and dashes, and cannot start or end with a dash.",
+  );
+}
 }
 
 function validateSingle(config: FunctionConfig): ValidatedSingle {