content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.beam.sdk.util;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.instanceOf;
  import static org.hamcrest.Matchers.is;
  import static org.hamcrest.Matchers.isA;
  import static org.hamcrest.Matchers.not;
  import static org.junit.Assert.assertEquals;
  
  import java.io.IOException;
  import org.hamcrest.Description;
  import org.hamcrest.FeatureMatcher;
  import org.hamcrest.Matcher;
  import org.hamcrest.TypeSafeMatcher;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link UserCodeException} functionality. */
  @RunWith(JUnit4.class)
  public class UserCodeExceptionTest {
  
    @Rule public ExpectedException thrown = ExpectedException.none();
  
    @Test
    public void existingUserCodeExceptionsNotWrapped() {
      UserCodeException existing = UserCodeException.wrap(new IOException());
      UserCodeException wrapped = UserCodeException.wrap(existing);
  
      assertEquals(existing, wrapped);
    }
  
    @Test
    public void testCauseIsSet() {
      thrown.expectCause(isA(IOException.class));
      throwUserCodeException();
    }
  
    @Test
    public void testStackTraceIsTruncatedToUserCode() {
      thrown.expectCause(hasBottomStackFrame(method("userCode")));
      throwUserCodeException();
    }
  
    @Test
    public void testStackTraceIsTruncatedProperlyFromHelperMethod() {
      thrown.expectCause(hasBottomStackFrame(method("userCode")));
      throwUserCodeExceptionFromHelper();
    }
  
    @Test
    public void testWrapIfOnlyWrapsWhenTrue() {
      IOException cause = new IOException();
      RuntimeException wrapped = UserCodeException.wrapIf(true, cause);
  
      assertThat(wrapped, is(instanceOf(UserCodeException.class)));
    }
  
    @Test
    public void testWrapIfReturnsRuntimeExceptionWhenFalse() {
      IOException cause = new IOException();
      RuntimeException wrapped = UserCodeException.wrapIf(false, cause);
  
      assertThat(wrapped, is(not(instanceOf(UserCodeException.class))));
      assertEquals(cause, wrapped.getCause());
    }
  
    @Test
    public void testWrapIfReturnsSourceRuntimeExceptionWhenFalse() {
      RuntimeException runtimeException = new RuntimeException("oh noes!");
      RuntimeException wrapped = UserCodeException.wrapIf(false, runtimeException);
  
      assertEquals(runtimeException, wrapped);
    }
  
    @Test
    public void robustAgainstEmptyStackTrace() {
      RuntimeException runtimeException = new RuntimeException("empty stack");
      runtimeException.setStackTrace(new StackTraceElement[0]);
      RuntimeException wrapped = UserCodeException.wrap(runtimeException);
      assertEquals(runtimeException, wrapped.getCause());
    }
  
    private void throwUserCodeException() {
      try {
        userCode();
      } catch (Exception ex) {
        throw UserCodeException.wrap(ex);
      }
    }
  
    private void throwUserCodeExceptionFromHelper() {
      try {
        userCode();
      } catch (Exception ex) {
        throw wrap(ex);
      }
    }
  
    private UserCodeException wrap(Throwable t) {
      throw UserCodeException.wrap(t);
    }
  
    private void userCode() throws IOException {
      userCode2();
    }
  
    private void userCode2() throws IOException {
      userCode3();
    }
  
    private void userCode3() throws IOException {
      IOException ex = new IOException("User processing error!");
      throw ex;
    }
  
    private static ThrowableBottomStackFrameMethodMatcher hasBottomStackFrame(
        Matcher<StackTraceElement> frameMatcher) {
      return new ThrowableBottomStackFrameMethodMatcher(frameMatcher);
    }
  
    private static StackFrameMethodMatcher method(String methodName) {
      return new StackFrameMethodMatcher(is(methodName));
    }
  
    static class ThrowableBottomStackFrameMethodMatcher
        extends FeatureMatcher<Throwable, StackTraceElement> {
  
      public ThrowableBottomStackFrameMethodMatcher(Matcher<StackTraceElement> subMatcher) {
        super(subMatcher, "Throwable with bottom stack frame:", "stack frame");
      }
  
      @Override
      protected StackTraceElement featureValueOf(Throwable actual) {
        StackTraceElement[] stackTrace = actual.getStackTrace();
        return stackTrace[stackTrace.length - 1];
      }
    }
  
    static class StackFrameMethodMatcher extends TypeSafeMatcher<StackTraceElement> {
  
      private Matcher<String> methodNameMatcher;
  
      public StackFrameMethodMatcher(Matcher<String> methodNameMatcher) {
        this.methodNameMatcher = methodNameMatcher;
      }
  
      @Override
      public void describeTo(Description description) {
        description.appendText("stack frame where method name ");
        methodNameMatcher.describeTo(description);
      }
  
      @Override
      protected boolean matchesSafely(StackTraceElement item) {
        return methodNameMatcher.matches(item.getMethodName());
      }
    }
  }
  