Temporary Files

Sometimes it is required for a test to create a file and delete it after test, deleting it manually may lead to flaky test.

For example, you may be using a temporary file during a test. If the test passes successfully, your clean up code will execute and the file will be deleted. But in case the assertion fails or another error occurs, which may have caused the file to not be deleted, you will get a stale file which might affect the test on the next run (file cannot be overwritten exception and so on).

Kotest provides a function tempfile() which you can use in your Spec to create a temporary file for your tests, and which Kotest will take the responsibility of cleaning up after running all tests in the Spec. This way your tests does not have to worry about deleting the temporary file.

class MySpec : FunSpec({

   val file = tempfile()

   test("a temporary file dependent test") {
      //...
   }
})

Temporary Directories

Similar to temp files, we can create a temp dir using tempdir().

class MySpec : FunSpec({

   val dir = tempdir()

   test("a temporary dir dependent test") {
      //...
   }
})