sdks/java/core/src/test/java/org/apache/beam/sdk/util/InstanceBuilderTest.java

/*
 * 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 org.apache.beam.sdk.values.TupleTag;
import org.hamcrest.Matchers;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests of InstanceBuilder. */
@RunWith(JUnit4.class)
@SuppressWarnings("rawtypes")
public class InstanceBuilderTest {

  @Rule public ExpectedException expectedEx = ExpectedException.none();

  @SuppressWarnings("unused")
  private static TupleTag createTag(String id) {
    return new TupleTag(id);
  }

  @Test
  public void testFullNameLookup() throws Exception {
    TupleTag tag =
        InstanceBuilder.ofType(TupleTag.class)
            .fromClassName(InstanceBuilderTest.class.getName())
            .fromFactoryMethod("createTag")
            .withArg(String.class, "hello world!")
            .build();

    Assert.assertEquals("hello world!", tag.getId());
  }

  @Test
  public void testConstructor() throws Exception {
    TupleTag tag =
        InstanceBuilder.ofType(TupleTag.class).withArg(String.class, "hello world!").build();

    Assert.assertEquals("hello world!", tag.getId());
  }

  @Test
  public void testBadMethod() throws Exception {
    expectedEx.expect(RuntimeException.class);
    expectedEx.expectMessage(Matchers.containsString("Unable to find factory method"));

    InstanceBuilder.ofType(String.class)
        .fromClassName(InstanceBuilderTest.class.getName())
        .fromFactoryMethod("nonexistantFactoryMethod")
        .withArg(String.class, "hello")
        .withArg(String.class, " world!")
        .build();
  }

  @Test
  public void testBadArgs() throws Exception {
    expectedEx.expect(RuntimeException.class);
    expectedEx.expectMessage(Matchers.containsString("Unable to find factory method"));

    InstanceBuilder.ofType(TupleTag.class)
        .fromClassName(InstanceBuilderTest.class.getName())
        .fromFactoryMethod("createTag")
        .withArg(String.class, "hello")
        .withArg(Integer.class, 42)
        .build();
  }

  @Test
  public void testBadReturnType() throws Exception {
    expectedEx.expect(RuntimeException.class);
    expectedEx.expectMessage(Matchers.containsString("must be assignable to String"));

    InstanceBuilder.ofType(String.class)
        .fromClassName(InstanceBuilderTest.class.getName())
        .fromFactoryMethod("createTag")
        .withArg(String.class, "hello")
        .build();
  }

  @Test
  public void testWrongType() throws Exception {
    expectedEx.expect(RuntimeException.class);
    expectedEx.expectMessage(Matchers.containsString("must be assignable to TupleTag"));

    InstanceBuilder.ofType(TupleTag.class)
        .fromClassName(InstanceBuilderTest.class.getName())
        .build();
  }
}