Create ExperimentalTestRunner which is just the same as BazelTestRunner, but a testbed of upcoming changes, without breaking existing test targets.

To use the alternate test runner a java test should add the tag "experimental_testrunner" and depend on "@bazel_tools//tools/jdk:ExperimentalTestRunner_deploy.jar" (instead of @bazel_tools//tools/jdk:TestRunner_deploy.jar)

--
PiperOrigin-RevId: 149536298
MOS_MIGRATED_REVID=149536298

7 files changed, 269 insertions, 21 deletions

diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BUILD b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BUILD
index 1699cb882b..c5a8006794 100644
--- a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BUILD
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BUILD
@@ -7,9 +7,41 @@ DEFAULT_VISIBILITY = [
 
 package(default_visibility = ["//src:__subpackages__"])
 
+filegroup(
+    name = "common_runner_java_files",
+    srcs = glob(
+        ["*.java"],
+        exclude =
+            [
+                "BazelTestRunner.java",
+                "ExperimentalTestRunner.java",
+            ],
+    ),
+)
+
 java_library(
     name = "test_runner",
-    srcs = glob(["*.java"]),
+    srcs = [
+        "BazelTestRunner.java",
+        ":common_runner_java_files",
+    ],
+    data = ["//tools:test_sharding_compliant"],
+    deps = [
+        "//src/java_tools/junitrunner/java/com/google/testing/junit/runner/internal",
+        "//src/java_tools/junitrunner/java/com/google/testing/junit/runner/junit4",
+        "//src/java_tools/junitrunner/java/com/google/testing/junit/runner/model",
+        "//src/java_tools/junitrunner/java/com/google/testing/junit/runner/sharding",
+        "//src/java_tools/junitrunner/java/com/google/testing/junit/runner/util",
+        "//third_party:junit4",
+    ],
+)
+
+java_library(
+    name = "experimental_test_runner",
+    srcs = [
+        "ExperimentalTestRunner.java",
+        ":common_runner_java_files",
+    ],
     data = ["//tools:test_sharding_compliant"],
     deps = [
         "//src/java_tools/junitrunner/java/com/google/testing/junit/runner/internal",
@@ -27,6 +59,12 @@ java_binary(
     runtime_deps = [":test_runner"],
 )
 
+java_binary(
+    name = "ExperimentalRunner",
+    main_class = "com.google.testing.junit.runner.ExperimentalTestRunner",
+    runtime_deps = [":experimental_test_runner"],
+)
+
 filegroup(
     name = "srcs",
     testonly = 0,  # All srcs should be not test only, overwrite package default.
diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunner.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunner.java
index 74a6826f88..66d7d91a67 100644
--- a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunner.java
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunner.java
@@ -18,8 +18,6 @@ import com.google.testing.junit.runner.internal.StackTraces;
 import com.google.testing.junit.runner.junit4.JUnit4InstanceModules.Config;
 import com.google.testing.junit.runner.junit4.JUnit4InstanceModules.SuiteClass;
 import com.google.testing.junit.runner.junit4.JUnit4Runner;
-import com.google.testing.junit.runner.model.AntXmlResultWriter;
-import com.google.testing.junit.runner.model.XmlResultWriter;
 import java.io.PrintStream;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
@@ -200,18 +198,4 @@ public class BazelTestRunner {
       }
     }
   }
-
-  static class BazelTestRunnerModule {
-    static XmlResultWriter resultWriter(AntXmlResultWriter impl) {
-      return impl;
-    }
-
-    static PrintStream stdoutStream() {
-      return System.out;
-    }
-
-    static PrintStream stderrStream() {
-      return System.err;
-    }
-  }
 }
diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunnerModule.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunnerModule.java
new file mode 100644
index 0000000000..a3c1c6f796
--- /dev/null
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/BazelTestRunnerModule.java
@@ -0,0 +1,36 @@
+// Copyright 2017 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.testing.junit.runner;
+
+import com.google.testing.junit.runner.model.AntXmlResultWriter;
+import com.google.testing.junit.runner.model.XmlResultWriter;
+import java.io.PrintStream;
+
+/**
+ * Originally a Dagger module extracted out of {@link BazelTestRunner}.
+ */
+class BazelTestRunnerModule {
+  static XmlResultWriter resultWriter(AntXmlResultWriter impl) {
+    return impl;
+  }
+
+  static PrintStream stdoutStream() {
+    return System.out;
+  }
+
+  static PrintStream stderrStream() {
+    return System.err;
+  }
+}
diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ExperimentalTestRunner.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ExperimentalTestRunner.java
new file mode 100644
index 0000000000..f13915e8e9
--- /dev/null
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ExperimentalTestRunner.java
@@ -0,0 +1,191 @@
+// Copyright 2017 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.testing.junit.runner;
+
+import com.google.testing.junit.runner.internal.StackTraces;
+import com.google.testing.junit.runner.junit4.JUnit4InstanceModules.Config;
+import com.google.testing.junit.runner.junit4.JUnit4InstanceModules.SuiteClass;
+import com.google.testing.junit.runner.junit4.JUnit4Runner;
+import java.io.PrintStream;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * For now the same as {@link BazelTestRunner} but intended to be a testbed to try out new features,
+ * without breeaking existing tests.
+ */
+public class ExperimentalTestRunner {
+  /**
+   * If no arguments are passed on the command line, use this System property to
+   * determine which test suite to run.
+   */
+  static final String TEST_SUITE_PROPERTY_NAME = "bazel.test_suite";
+
+  private ExperimentalTestRunner() {
+    // utility class; should not be instantiated
+  }
+
+  /**
+   * Takes as arguments the classes or packages to test.
+   *
+   * <p>To help just run one test or method in a suite, the test suite
+   * may be passed in via system properties (-Dbazel.test_suite).
+   * An empty args parameter means to run all tests in the suite.
+   * A non-empty args parameter means to run only the specified tests/methods.
+   *
+   * <p>Return codes:
+   * <ul>
+   * <li>Test runner failure, bad arguments, etc.: exit code of 2</li>
+   * <li>Normal test failure: exit code of 1</li>
+   * <li>All tests pass: exit code of 0</li>
+   * </ul>
+   */
+  public static void main(String[] args) {
+    PrintStream stderr = System.err;
+
+    String suiteClassName = System.getProperty(TEST_SUITE_PROPERTY_NAME);
+    System.out.println("WARNING: RUNNING EXPERIMENTAL TEST RUNNER");
+
+    if (args.length >= 1 && args[args.length - 1].equals("--persistent_test_runner")) {
+      System.err.println("Requested test strategy is currently unsupported.");
+      System.exit(1);
+    }
+
+    if (!checkTestSuiteProperty(suiteClassName)) {
+      System.exit(2);
+    }
+
+    int exitCode = runTestsInSuite(suiteClassName, args);
+
+    System.err.printf("%nExperimentalTestRunner exiting with a return value of %d%n", exitCode);
+    System.err.println("JVM shutdown hooks (if any) will run now.");
+    System.err.println("The JVM will exit once they complete.");
+    System.err.println();
+
+    printStackTracesIfJvmExitHangs(stderr);
+
+    DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+    Date shutdownTime = new Date();
+    String formattedShutdownTime = format.format(shutdownTime);
+    System.err.printf("-- JVM shutdown starting at %s --%n%n", formattedShutdownTime);
+    System.exit(exitCode);
+  }
+
+  /**
+   * Ensures that the bazel.test_suite in argument is not {@code null} or print error and
+   * explanation.
+   *
+   * @param testSuiteProperty system property to check
+   */
+  private static boolean checkTestSuiteProperty(String testSuiteProperty) {
+    if (testSuiteProperty == null) {
+      System.err.printf(
+          "Error: The test suite Java system property %s is required but missing.%n",
+          TEST_SUITE_PROPERTY_NAME);
+      System.err.println();
+      System.err.println("This property is set automatically when running with Bazel like such:");
+      System.err.printf("  java -D%s=[test-suite-class] %s%n",
+          TEST_SUITE_PROPERTY_NAME, ExperimentalTestRunner.class.getName());
+      System.err.printf("  java -D%s=[test-suite-class] -jar [deploy-jar]%n",
+          TEST_SUITE_PROPERTY_NAME);
+      System.err.println("E.g.:");
+      System.err.printf("  java -D%s=org.example.testing.junit.runner.SmallTests %s%n",
+          TEST_SUITE_PROPERTY_NAME, ExperimentalTestRunner.class.getName());
+      System.err.printf("  java -D%s=org.example.testing.junit.runner.SmallTests "
+              + "-jar SmallTests_deploy.jar%n",
+          TEST_SUITE_PROPERTY_NAME);
+      return false;
+    }
+    return true;
+  }
+
+  private static int runTestsInSuite(String suiteClassName, String[] args) {
+    Class<?> suite = getTestClass(suiteClassName);
+
+    if (suite == null) {
+      // No class found corresponding to the system property passed in from Bazel
+      if (args.length == 0 && suiteClassName != null) {
+        System.err.printf("Class not found: [%s]%n", suiteClassName);
+        return 2;
+      }
+    }
+
+    // TODO(kush): Use a new classloader for the following instantiation.
+    JUnit4Runner runner =
+        JUnit4Bazel.builder()
+            .suiteClass(new SuiteClass(suite))
+            .config(new Config(args))
+            .build()
+            .runner();
+    return runner.run().wasSuccessful() ? 0 : 1;
+  }
+
+  private static Class<?> getTestClass(String name) {
+    if (name == null) {
+      return null;
+    }
+
+    try {
+      return Class.forName(name);
+    } catch (ClassNotFoundException e) {
+      return null;
+    }
+  }
+
+  /**
+   * Prints out stack traces if the JVM does not exit quickly. This can help detect shutdown hooks
+   * that are preventing the JVM from exiting quickly.
+   *
+   * @param out Print stream to use
+   */
+  private static void printStackTracesIfJvmExitHangs(final PrintStream out) {
+    Thread thread = new Thread(new Runnable() {
+      @Override
+      public void run() {
+        sleepUninterruptibly(5);
+        out.println("JVM still up after five seconds. Dumping stack traces for all threads.");
+        StackTraces.printAll(out);
+      }
+    }, "ExperimentalTestRunner: Print stack traces if JVM exit hangs");
+
+    thread.setDaemon(true);
+    thread.start();
+  }
+
+  /**
+   * Invokes SECONDS.{@link TimeUnit#sleep(long) sleep(sleepForSeconds)} uninterruptibly.
+   */
+  private static void sleepUninterruptibly(long sleepForSeconds) {
+    boolean interrupted = false;
+    try {
+      long end = System.nanoTime() + TimeUnit.SECONDS.toNanos(sleepForSeconds);
+      while (true) {
+        try {
+          // TimeUnit.sleep() treats negative timeouts just like zero.
+          TimeUnit.NANOSECONDS.sleep(end - System.nanoTime());
+          return;
+        } catch (InterruptedException e) {
+          interrupted = true;
+        }
+      }
+    } finally {
+      if (interrupted) {
+        Thread.currentThread().interrupt();
+      }
+    }
+  }
+}
diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ResultWriterFactory.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ResultWriterFactory.java
index ce8c70e790..34dcdf511c 100644
--- a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ResultWriterFactory.java
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/ResultWriterFactory.java
@@ -32,8 +32,7 @@ public final class ResultWriterFactory implements Factory<XmlResultWriter> {
 
   @Override
   public XmlResultWriter get() {
-    XmlResultWriter xmlResultWriter =
-        BazelTestRunner.BazelTestRunnerModule.resultWriter(implSupplier.get());
+    XmlResultWriter xmlResultWriter = BazelTestRunnerModule.resultWriter(implSupplier.get());
     assert xmlResultWriter != null;
     return xmlResultWriter;
   }
diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StderrStreamFactory.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StderrStreamFactory.java
index 22e45aeb84..be2303b793 100644
--- a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StderrStreamFactory.java
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StderrStreamFactory.java
@@ -25,7 +25,7 @@ public enum StderrStreamFactory implements Factory<PrintStream> {
 
   @Override
   public PrintStream get() {
-    PrintStream printStream = BazelTestRunner.BazelTestRunnerModule.stderrStream();
+    PrintStream printStream = BazelTestRunnerModule.stderrStream();
     assert printStream != null;
     return printStream;
   }
diff --git a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StdoutStreamFactory.java b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StdoutStreamFactory.java
index 6e0d6463f3..57517d5309 100644
--- a/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StdoutStreamFactory.java
+++ b/src/java_tools/junitrunner/java/com/google/testing/junit/runner/StdoutStreamFactory.java
@@ -25,7 +25,7 @@ public enum StdoutStreamFactory implements Factory<PrintStream> {
 
   @Override
   public PrintStream get() {
-    PrintStream printStream = BazelTestRunner.BazelTestRunnerModule.stdoutStream();
+    PrintStream printStream = BazelTestRunnerModule.stdoutStream();
     assert printStream != null;
     return printStream;
   }