flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/test/util/AbstractTestBase.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.flink.test.util;

import org.apache.flink.runtime.testutils.MiniClusterResourceConfiguration;
import org.apache.flink.testutils.junit.category.AlsoRunWithSchedulerNG;
import org.apache.flink.util.FileUtils;

import org.junit.ClassRule;
import org.junit.experimental.categories.Category;
import org.junit.rules.TemporaryFolder;

import java.io.File;
import java.io.IOException;

/**
 * Base class for unit tests that run multiple tests and want to reuse the same
 * Flink cluster. This saves a significant amount of time, since the startup and
 * shutdown of the Flink clusters (including actor systems, etc) usually dominates
 * the execution of the actual tests.
 *
 * <p>To write a unit test against this test base, simply extend it and add
 * one or more regular test methods and retrieve the StreamExecutionEnvironment from
 * the context:
 *
 * <pre>
 *   {@literal @}Test
 *   public void someTest() {
 *       ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
 *       // test code
 *       env.execute();
 *   }
 *
 *   {@literal @}Test
 *   public void anotherTest() {
 *       StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
 *       // test code
 *       env.execute();
 *   }
 *
 * </pre>
 */
@Category(AlsoRunWithSchedulerNG.class)
public abstract class AbstractTestBase extends TestBaseUtils {

	private static final int DEFAULT_PARALLELISM = 4;

	@ClassRule
	public static MiniClusterWithClientResource miniClusterResource = new MiniClusterWithClientResource(
		new MiniClusterResourceConfiguration.Builder()
			.setNumberTaskManagers(1)
			.setNumberSlotsPerTaskManager(DEFAULT_PARALLELISM)
			.build());

	@ClassRule
	public static final TemporaryFolder TEMPORARY_FOLDER = new TemporaryFolder();


	// --------------------------------------------------------------------------------------------
	//  Temporary File Utilities
	// --------------------------------------------------------------------------------------------

	public String getTempDirPath(String dirName) throws IOException {
		File f = createAndRegisterTempFile(dirName);
		return f.toURI().toString();
	}

	public String getTempFilePath(String fileName) throws IOException {
		File f = createAndRegisterTempFile(fileName);
		return f.toURI().toString();
	}

	public String createTempFile(String fileName, String contents) throws IOException {
		File f = createAndRegisterTempFile(fileName);
		if (!f.getParentFile().exists()) {
			f.getParentFile().mkdirs();
		}
		f.createNewFile();
		FileUtils.writeFileUtf8(f, contents);
		return f.toURI().toString();
	}

	public File createAndRegisterTempFile(String fileName) throws IOException {
		return new File(TEMPORARY_FOLDER.newFolder(), fileName);
	}
}