Deleting a file and directory in JUnit

Question

I am writing a test for a method that creates a file in a directory. This is what my JUnit test looks like:

@Before public void setUp(){ objectUnderTest = new ClassUnderTest(); //assign another directory path for testing using powermock WhiteBox.setInternalState(objectUnderTest, "dirPathField", mockDirPathObject); nameOfFile = "name.txt"; textToWrite = "some text"; } @Test public void shouldCreateAFile(){ //create file and write test objectUnderTest.createFile(nameOfFile, textToWrite); /* this method creates the file in mockPathObject and performs FileWriter.write(text); FileWriter.close(); */ File expect = new File(mockPathObject + "\\" + nameOfFile); assertTrue(expect.exist()); //assert if text is in the file -> it will not be called if first assert fails } @After public void tearDown(){ File destroyFile = new File(mockPathObject + "\\" + nameOfFile); File destroyDir = new File(mockPathObject); //here my problem destroyFile.delete(); //why is this returning false? destroyDir.delete(); //will also return false since file was not deleted above } 

I managed to delete the file using deleteOnExit (), but I cannot delete the directory using delete or deleteOnExit. I will also run other tests for other scripts in this test script, so I don't want to use deleteOnExit.

I do not know why I cannot delete it in the JUnit test script until I can delete the file created and modified by FileWriter at runtime when the code is not a JUnit test. I also tried to execute the endless method after the testing method and delete the file manually, but it tells me that another program is still using the file, although I can change its contents.

Hopefully someone can suggest a way to delete files and directories created during the tests. Thanks: D

For clarity, the test method I looks like this: The single test method that calls FileWriter

Edit: Here is a validation method

  public void createFile(String fileName, String text){ //SOME_PATH is a static string which is a field of the class File dir = new File(SOME_PATH); //I modified SOME_PATH using whitebox for testing if(!dir.exists()){ booelan createDir = dir.mkdirs(); if(!createDir){ sysout("cannot make dir"); return; } } try{ FileWriter fileWrite = new FileWriter(dir.getAbsolutePath() + "/" + fileName, true); fileWrite.write(text); fileWrite.close(); } catch(Exception e){ e.printStackTrace(); } } 

I cannot change this method as other developers have created it. I was simply assigned to create unit tests to automate testing. Thanks.

Answer 1

Use the @Rule annotation and the TemporaryFolder class for the folder that you want to delete.

http://kentbeck.github.com/junit/javadoc/4.10/org/junit/Rule.html(404 not found)

Update usage example http://junit.org/junit4/javadoc/4.12/org/junit/rules/TemporaryFolder.html :

 public static class HasTempFolder { @Rule public TemporaryFolder folder= new TemporaryFolder(); @Test public void testUsingTempFolder() throws IOException { File createdFile= folder.newFile("myfile.txt"); File createdFolder= folder.newFolder("subfolder"); // ... } } 

Answer 2

So I usually clean the files:

 @AfterClass public static void clean() { File dir = new File(DIR_PATH); for (File file:dir.listFiles()) { file.delete(); } dir.delete(); } 

Your directory must be empty to remove it, make sure that other testing methods do not create more files there.

Make sure you close the FileWriter instance in the finally block .

Answer 3

Make sure that the objectUnderTest.createFile(nameOfFile, textToWrite) actually closes all open threads?