Add tests for Prolog's handling of SubmitRecords

Prolog handles the results of the defined `submit_rule` in a specific
way: once an OK record is found, processing of the other SubmitRecords
is stopped. This leads to weird situations, for instance if we have a
*not_ready* record _before_ the *ok* one.

Add a test to ensure the behavior isn't changed inadvertently and to
document it with simple and reproducible test cases.

Change-Id: I06d054a47c47e05d3e453e4520474cc2d26c98e4

javatests/com/google/gerrit/common/data/SubmitRecordTest.java

@@ -0,0 +1,52 @@
+// Copyright (C) 2018 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.common.data;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import org.junit.Test;
+
+public class SubmitRecordTest {
+
+  private static SubmitRecord OK_RECORD;
+  private static SubmitRecord NOT_READY_RECORD;
+
+  static {
+    OK_RECORD = new SubmitRecord();
+    OK_RECORD.status = SubmitRecord.Status.OK;
+
+    NOT_READY_RECORD = new SubmitRecord();
+    NOT_READY_RECORD.status = SubmitRecord.Status.NOT_READY;
+  }
+
+  @Test
+  public void findOkRecord() {
+    Collection<SubmitRecord> submitRecords = new ArrayList<>();
+    submitRecords.add(NOT_READY_RECORD);
+    submitRecords.add(OK_RECORD);
+
+    assertThat(SubmitRecord.findOkRecord(submitRecords).isPresent()).isTrue();
+  }
+
+  @Test
+  public void emptyResultIfInvalid() {
+    Collection<SubmitRecord> submitRecords = new ArrayList<>();
+    submitRecords.add(NOT_READY_RECORD);
+
+    assertThat(SubmitRecord.findOkRecord(submitRecords).isPresent()).isFalse();
+  }
+}