How do I mock a static void method (not with doNothing or invocation -> null) using Mockito.mocke-CodePudding

I have the following classes

class FileDownloader {
    public static void downloadFile(String repoUrl, String filename) throws IOException {
        // Downloads file from internet
    }
}

class FileDownloaderAndProcessor {
    public static void downloadAndProcessFile() throws IOException {
        //run some processing to figure out what to download
        FileDownloader.downloadFile(a, b);
        //run various processing on downloaded file
    }
}

I used to mock FileDownloader with PowerMockito.doAnswer, where I could basically mock the downloadFiles function by copying a local file from one place to another to simulate the download, then run various tests on the postproccessing

PowerMockito.doAnswer(invocation -> {
//copy from local location x to y depending on arguments
}.when(FileDownloader.class, "downloadFile").etc etc

Due to a recent spring upgrade, we can no longer use powermock and are migrating to MockedStatic. However, I don't see the doAnswer functionality in MockedStatic. I really don't want the tests to require an internet connection to run. How do I mock this void method?

Mockito version: org.mockito:mockito-core:jar:4.0.0 org.mockito:mockito-inline:jar:4.0.0

CodePudding user response：

You can try when...thenAnswer... on MockedStatic provided by Mockito.

try (MockedStatic<FileDownloader> mockedFileDownloader = Mockito.mockStatic(FileDownloader.class)) {
    mockedFileDownloader.when(() -> mockedFileDownloader.downloadFile(repoUrl, filename))
        .thenAnswer(invocation -> {
            // copy from local location x to y depending on arguments
            return null;
        });
}

CodePudding user response：

Since all your static classes seem to have only one method you can simply mock the entire class.

Mockito.mockStatic(FileDownloader.class, invocationOnMock -> {
    System.out.println("Do Something that simulates the download");
    return null;
});

FileDownloader.downloadFile("someRepo", "someFile");