1 files changed, 94 insertions, 0 deletions
diff --git a/src/test/java/com/google/devtools/build/lib/integration/blackbox/framework/junit/TimeoutTestWatcher.java b/src/test/java/com/google/devtools/build/lib/integration/blackbox/framework/junit/TimeoutTestWatcher.java
new file mode 100644
index 0000000000..c0e87f7093
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/integration/blackbox/framework/junit/TimeoutTestWatcher.java
@@ -0,0 +1,94 @@
+// Copyright 2018 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.integration.blackbox.framework.junit;
+
+import java.util.concurrent.TimeoutException;
+import org.junit.rules.TestWatcher;
+import org.junit.rules.Timeout;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+/**
+ * Test watcher, which sets a timeout for the JUnit test and allows to execute some action on
+ * timeout. Uses JUnit's org.junit.rules.Timeout rule to set up a timeout; catches timeout exception
+ * thrown fromTimeout rule, calls the {@link onTimeout} method, and re-throws the exception.
+ *
+ * <p>Useful to dump test state information before failing on timeout.
+ */
+public abstract class TimeoutTestWatcher extends TestWatcher {
+  private String name;
+
+  protected abstract long getTimeoutMillis();
+
+  protected abstract boolean onTimeout();
+
+  @Override
+  protected void starting(Description description) {
+    name = description.getMethodName();
+  }
+
+  @Override
+  protected void finished(Description description) {
+    name = null;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  @Override
+  public Statement apply(Statement base, Description description) {
+    // we are using exception wrapping, because unfortunately JUnit's Timeout throws
+    // java.util.Exception on timeout, which is hard to distinguish from other cases
+    Statement wrapper =
+        new Statement() {
+          @Override
+          public void evaluate() throws Throwable {
+            try {
+              base.evaluate();
+            } catch (Throwable th) {
+              throw new ExceptionWrapper(th);
+            }
+          }
+        };
+
+    return new Statement() {
+      @Override
+      public void evaluate() throws Throwable {
+        try {
+          new Timeout((int) getTimeoutMillis()).apply(wrapper, description).evaluate();
+        } catch (ExceptionWrapper wrapper) {
+          // original test exception
+          throw wrapper.getCause();
+        } catch (Exception e) {
+          // timeout exception
+          if (!onTimeout()) {
+            throw new TimeoutException(e.getMessage());
+          }
+        }
+      }
+    };
+  }
+
+  /**
+   * Exception wrapper wrap-and-caught any exception from the test; this guarantees that we
+   * differentiate timeout exception thrown just as java.util.Exception from the test exceptions
+   */
+  private static class ExceptionWrapper extends Throwable {
+    ExceptionWrapper(Throwable cause) {
+      super(cause);
+    }
+  }
+}