BEP: always close stream, even if aborted due to missing tests

If testing is requested, but no tests are found, the build is aborted.
Ensure that even in this case the steam of  build events is internally
closed (i.e., all announced events are reported, the last event is marked
as such).

Change-Id: I88763ed6ccd7793deedbcb3428df7e8d289efa23
PiperOrigin-RevId: 168364127

src/main/java/com/google/devtools/build/lib/runtime/BuildEventStreamer.java

@@ -57,6 +57,7 @@
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.events.Reporter;
+import com.google.devtools.build.lib.runtime.commands.NoTestsFound;
 import com.google.devtools.build.lib.util.Pair;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -373,6 +374,11 @@ public void buildInterrupted(BuildInterruptedEvent event) {
     abortReason = AbortReason.USER_INTERRUPTED;
   }
 
+  @Subscribe
+  public void noTestsFound(NoTestsFound event) {
+    buildComplete();
+  }
+
   @Subscribe
   public void buildEvent(BuildEvent event) {
     if (isActionWithoutError(event)

src/main/java/com/google/devtools/build/lib/runtime/commands/NoTestsFound.java

@@ -0,0 +1,18 @@
+// Copyright 2014 The Bazel Authors. All rights reserved.
+//
+// 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.devtools.build.lib.runtime.commands;
+
+/** This event is posted by the {@link TestCommand} if no tests were found. */
+public class NoTestsFound {}

src/main/java/com/google/devtools/build/lib/runtime/commands/TestCommand.java

@@ -137,6 +137,7 @@ private ExitCode doTest(CommandEnvironment env,
     if (testTargets.isEmpty()) {
       env.getReporter().handle(Event.error(
           null, "No test targets were found, yet testing was requested"));
+      env.getEventBus().post(new NoTestsFound());
       return buildResult.getSuccess() ? ExitCode.NO_TESTS_FOUND : buildResult.getExitCondition();
     }
 

src/test/shell/integration/build_event_stream_test.sh

@@ -101,6 +101,11 @@ filegroup(
   name = "outergroup",
   srcs = ["sourcefileC", ":innergroup"],
 )
+genrule(
+  name = "not_a_test",
+  outs = ["not_a_test.txt"],
+  cmd = "touch $@",
+)
 EOF
 cat > simpleaspect.bzl <<EOF
 def _simple_aspect_impl(target, ctx):
@@ -616,6 +621,14 @@ function test_test_fails_to_build() {
   (bazel test --build_event_text_file=$TEST_log \
          pkg:test_that_fails_to_build && fail "test failure expected") || true
   expect_not_log '^test_summary'
+  expect_log 'last_message: true'
+}
+
+function test_no_tests_found() {
+  (bazel test --build_event_text_file=$TEST_log \
+         pkg:not_a_test && fail "failure expected") || true
+  expect_not_log '^test_summary'
+  expect_log 'last_message: true'
 }
 
 run_suite "Integration tests for the build event stream"