de.systemoutprintln.junit4examples.rules.TemporaryFolderRuleTest.java Source code

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Here is the source code for de.systemoutprintln.junit4examples.rules.TemporaryFolderRuleTest.java

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/*
 * 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 de.systemoutprintln.junit4examples.rules;

import static de.systemoutprintln.junit4examples.matchers.IsFileExisting.exists;
import static org.hamcrest.core.IsNot.not;
import static org.hamcrest.core.IsCollectionContaining.*;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.io.IOException;
import java.util.Collection;

import org.apache.commons.io.FileUtils;
import org.junit.AfterClass;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

public class TemporaryFolderRuleTest {

    @Rule
    public TemporaryFolder folder = new TemporaryFolder();

    // static to show that files are cleaned up in @AfterClass 
    private static File txtFile, tempFolder;

    @Test
    public void createTempFile() throws IOException {
        txtFile = folder.newFile("some.txt");

        // it actually exists! :)
        assertTrue(txtFile.exists());
        // and we can write to it...
        assertTrue(txtFile.canWrite());
        // let's try that
        FileUtils.writeStringToFile(txtFile, "I'm writing to a temp file!");
        String contents = FileUtils.readFileToString(txtFile);

        assertEquals("I'm writing to a temp file!", contents);
    }

    @Test
    public void createTempFolder() throws IOException {
        // the same works for dirs... nice!
        tempFolder = folder.newFolder("tmp");
        File childFile = new File(tempFolder, "child.txt");
        childFile.createNewFile();

        @SuppressWarnings("unchecked")
        Collection<File> containedFiles = FileUtils.listFiles(tempFolder, new String[] { "txt" }, false);

        assertThat(containedFiles, hasItem(childFile));
    }

    @AfterClass
    public static void tearDownAfterClass() throws Exception {
        // everything is cleaned up after test execution
        assertThat(txtFile, not(exists()));
        assertThat(tempFolder, not(exists()));
    }

}