Allow to specify the author of a new comment of the test API

Change-Id: I48ef685eef44993932452e03e18ba7d4e7d4d1aa

java/com/google/gerrit/extensions/common/testing/AccountInfoSubject.java

@@ -0,0 +1,50 @@
+// Copyright (C) 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.extensions.common.testing;
+
+import static com.google.common.truth.Truth.assertAbout;
+
+import com.google.common.truth.FailureMetadata;
+import com.google.common.truth.IntegerSubject;
+import com.google.common.truth.Subject;
+import com.google.gerrit.extensions.common.AccountInfo;
+
+/** A Truth subject for {@link AccountInfo} instances. */
+public class AccountInfoSubject extends Subject {
+
+  private final AccountInfo accountInfo;
+
+  public static AccountInfoSubject assertThat(AccountInfo accountInfo) {
+    return assertAbout(accounts()).that(accountInfo);
+  }
+
+  public static Factory<AccountInfoSubject, AccountInfo> accounts() {
+    return AccountInfoSubject::new;
+  }
+
+  private AccountInfoSubject(FailureMetadata metadata, AccountInfo accountInfo) {
+    super(metadata, accountInfo);
+    this.accountInfo = accountInfo;
+  }
+
+  public IntegerSubject id() {
+    return check("id").that(accountInfo()._accountId);
+  }
+
+  private AccountInfo accountInfo() {
+    isNotNull();
+    return accountInfo;
+  }
+}

java/com/google/gerrit/extensions/common/testing/CommentInfoSubject.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.extensions.common.testing;
 
 import static com.google.common.truth.Truth.assertAbout;
+import static com.google.gerrit.extensions.common.testing.AccountInfoSubject.accounts;
 import static com.google.gerrit.extensions.common.testing.RangeSubject.ranges;
 
 import com.google.common.truth.BooleanSubject;
@@ -90,6 +91,10 @@ public class CommentInfoSubject extends Subject {
     return check("inReplyTo").that(commentInfo().inReplyTo);
   }
 
+  public AccountInfoSubject author() {
+    return check("author").about(accounts()).that(commentInfo().author);
+  }
+
   public StringSubject tag() {
     return check("tag").that(commentInfo().tag);
   }