io.github.glytching.junit.extension.folder

Class TemporaryFolderExtension

java.lang.Object

io.github.glytching.junit.extension.folder.TemporaryFolderExtension

All Implemented Interfaces:

org.junit.jupiter.api.extension.Extension, org.junit.jupiter.api.extension.ParameterResolver

public class TemporaryFolderExtension
extends Object
implements org.junit.jupiter.api.extension.ParameterResolver

The temporary folder extension provides a test with access to temporary files and directories. The temporary folder extension provides a TemporaryFolder which you can use to create a temporary file or directory for use by your test. The TemporaryFolder can be injected into your test or test case with any of the following approaches:

• Instance variable injection into a @BeforeEach method. The TemporaryFolder will be destroyed during @AfterEach and no exception will be thrown in cases where the deletion fails. For example:

    private TemporaryFolder temporaryFolder;
  
    @BeforeEach
    public void setUp(TemporaryFolder temporaryFolder) {
        this.temporaryFolder = temporaryFolder
        // ...
    }
   

• Parameter injection into a @Test method. The TemporaryFolder will be destroyed during @AfterEach and no exception will be thrown in cases where the deletion fails. For example:

    @Test
    public void testUsingTemporaryFolder(TemporaryFolder temporaryFolder) {
        // ...
    }
   

• Class variable injection using a @BeforeAll method. Note: in this case all tests in the test case will share the same instance of the TemporaryFolder. The TemporaryFolder will be destroyed after any @AfterAll method completes and no exception will be thrown in cases where the deletion fails. For example:

    private static TemporaryFolder TEMPORARY_FOLDER;
  
    @BeforeAll
    public static void setUp(TemporaryFolder givenTemporaryFolder) {
        TEMPORARY_FOLDER = givenTemporaryFolder
        // ...
    }
   

Usage examples:

Injecting a TemporaryFolder in a @BeforeEach method:

 @ExtendWith(TemporaryFolderExtension.class)
 public class MyTest {

     private TemporaryFolder temporaryFolder;

     @BeforeEach
     public void setUp(TemporaryFolder temporaryFolder) {
         this.temporaryFolder = temporaryFolder
         // ...
     }

     @Test
     public void testUsingTemporaryFile() {
         File file = temporaryFolder.createFile("foo.txt");
         // ...
     }

     @Test
     public void testUsingTemporaryDirectory() {
         // use the temporary folder itself
         File root = temporaryFolder.getRoot();

         // create a sub directory within the temporary folder
         File file = temporaryFolder.createDirectory("foo");
         // ...
     }
 }
 

Injecting a TemporaryFolder in a @Test method:

 public class MyTest {

     @Test
     @ExtendWith(TemporaryFolderExtension.class)
     public void testUsingTemporaryFile(TemporaryFolder temporaryFolder) {
         File file = temporaryFolder.createFile("foo.txt");
         // ...
     }

     @Test
     @ExtendWith(TemporaryFolderExtension.class)
     public void testUsingTemporaryDirectory(TemporaryFolder temporaryFolder) {
         // use the temporary folder itself
         File root = temporaryFolder.getRoot();

         // create a sub directory within the temporary folder
         File file = temporaryFolder.createDirectory("foo");
         // ...
     }
 }
 

Since:

1.0.0

See Also:

JUnit 4 TemporaryFolder Rule

Constructor Summary

Constructors

Constructor and Description
TemporaryFolderExtension()

Method Summary

Modifier and Type	Method and Description
Object	resolveParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext, org.junit.jupiter.api.extension.ExtensionContext extensionContext) Provides a value for any parameter context which has passed the supportsParameter(ParameterContext, ExtensionContext) gate.
boolean	supportsParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext, org.junit.jupiter.api.extension.ExtensionContext extensionContext) Does this extension support injection for parameters of the type described by the given parameterContext?

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TemporaryFolderExtension

public TemporaryFolderExtension()

Method Detail

supportsParameter

public boolean supportsParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext,
                                 org.junit.jupiter.api.extension.ExtensionContext extensionContext)
                          throws org.junit.jupiter.api.extension.ParameterResolutionException

Does this extension support injection for parameters of the type described by the given parameterContext?

Specified by:

supportsParameter in interface org.junit.jupiter.api.extension.ParameterResolver

Parameters:

parameterContext - the context for the parameter for which an argument should be resolved

extensionContext - the context in which the current test or container is being executed

Returns:

true if the given parameterContext describes a parameter of type: TemporaryFolder, false otherwise

Throws:

org.junit.jupiter.api.extension.ParameterResolutionException

resolveParameter

public Object resolveParameter(org.junit.jupiter.api.extension.ParameterContext parameterContext,
                               org.junit.jupiter.api.extension.ExtensionContext extensionContext)
                        throws org.junit.jupiter.api.extension.ParameterResolutionException

Provides a value for any parameter context which has passed the supportsParameter(ParameterContext, ExtensionContext) gate.

Specified by:

resolveParameter in interface org.junit.jupiter.api.extension.ParameterResolver

Parameters:

parameterContext - the context for the parameter for which an argument should be resolved

extensionContext - the context in which the current test or container is being executed

Returns:

a new TemporaryFolder

Throws:

org.junit.jupiter.api.extension.ParameterResolutionException