I have a bunch of tests that require me to initialise a temporary directory with some files, so that the methods in my tests can read and write to it.
Currently, the solution is to implement a BeforeAll/BeforeEach tag and initialise the temporary directory for each test class.
As this is a common routine, it would be more reuse friendly if we could write an extension that encapsulates this routine, and which only needs to receive an input of a Path to initialise a temporary directory with all the files.
I envision the extension to look something like

DirectoryInitExtension.java

public class DirectoryInitExtension implements BeforeEachCallback {

    private Path TEST_DATA_FOLDER;

    @TempDir
    public Path tempDir;

    public static DirectoryInitExtension initializeWith(Path folder) {
        return new DirectoryInitExtension(folder);
    }

    @Override
    public void beforeEach(ExtensionContext extensionContext) throws IOException {
        // Copy files from TEST_DATA_FOLDER into tempDir, then return this tempDir as part of the test context.
    }
}

MainTest.java

 @RegisterExtension
    public static DirectoryResetExtension tempDir = DirectoryResetExtension.initializeWith(TEST_DATA_FOLDER);

However, as I soon learnt (thanks to a fast response here), TempDirs are not supported in extensions.

I wonder if it is a possibility to enable the same capabilities of TempDirs in extensions.

Deliverables

• Support TempDir in extensions? (Sorry, not too sure what to write here)