/*
* 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.transforms;
import static org.hamcrest.Matchers.equalTo;
import static org.junit.Assert.assertThat;
import java.io.Serializable;
import org.apache.beam.sdk.testing.TestPipeline;
import org.apache.beam.sdk.values.TypeDescriptors;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
/**
* Java 8 tests for {@link SimpleFunction}.
*/
@RunWith(JUnit4.class)
public class SimpleFunctionJava8Test implements Serializable {
@Rule
public final transient TestPipeline pipeline = TestPipeline.create();
/**
* Basic test of {@link MapElements} with a lambda (which is instantiated as a {@link
* SerializableFunction}).
*/
@Test
public void testGoodTypeForLambda() throws Exception {
SimpleFunction<Integer, String> fn =
new SimpleFunction<Integer, String>((Integer i) -> i.toString()) {};
assertThat(fn.getInputTypeDescriptor(), equalTo(TypeDescriptors.integers()));
assertThat(fn.getOutputTypeDescriptor(), equalTo(TypeDescriptors.strings()));
}
/**
* Basic test of {@link MapElements} with a lambda wrapped into a {@link SimpleFunction} to
* remember its type.
*/
@Test
public void testGoodTypeForMethodRef() throws Exception {
SimpleFunction<Integer, String> fn =
new SimpleFunction<Integer, String>(SimpleFunctionJava8Test::toStringThisThing) {};
assertThat(fn.getInputTypeDescriptor(), equalTo(TypeDescriptors.integers()));
assertThat(fn.getOutputTypeDescriptor(), equalTo(TypeDescriptors.strings()));
}
private static String toStringThisThing(Integer i) {
return i.toString();
}
}