enhance GCS TestUtils

Author: ywangd

test/fixtures/gcs-fixture/src/main/java/fixture/gcs/TestUtils.java

@@ -19,19 +19,28 @@
 
 public final class TestUtils {
 
+    public static final String DEFAULT_CLIENT_EMAIL = "[email protected]";
+
     private TestUtils() {}
 
     /**
      * Creates a random Service Account file for testing purpose
      */
     public static byte[] createServiceAccount(final Random random) {
-        return createServiceAccount(random, UUID.randomUUID().toString());
+        return createServiceAccount(random, UUID.randomUUID().toString(), DEFAULT_CLIENT_EMAIL);
     }
 
     /**
      * Creates a random Service Account file for testing purpose with a specific private key ID.
      */
     public static byte[] createServiceAccount(final Random random, String privateKeyId) {
+        return createServiceAccount(random, privateKeyId, DEFAULT_CLIENT_EMAIL);
+    }
+
+    /**
+     * Creates a random Service Account file for testing purpose with a specific private key ID and client email.
+     */
+    public static byte[] createServiceAccount(final Random random, String privateKeyId, String clientEmail) {
         try {
             final KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
             keyPairGenerator.initialize(2048);
@@ -45,7 +54,7 @@ public static byte[] createServiceAccount(final Random random, String privateKey
                     builder.field("project_id", "test");
                     builder.field("private_key_id", privateKeyId);
                     builder.field("private_key", "-----BEGIN PRIVATE KEY-----\n" + privateKey + "\n-----END PRIVATE KEY-----\n");
-                    builder.field("client_email", "[email protected]");
+                    builder.field("client_email", clientEmail);
                     builder.field("client_id", String.valueOf(Math.abs(random.nextLong())));
                 }
                 builder.endObject();