Unit test: Database message

Consider the ErrorStore and InfoStore from the lesson. Suppose the process(String message) method is used on a [WARN] message, which means it would end up in neither database. Write a test to verify that.

This exercise is part of the course

Introduction to Testing in Java

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Exercise instructions

Verify the message did not end up in infoStore.
Verify it also did not end up in errorStore using the times() verify approach.
In that same statement, add the database method, save(), that wasn't called.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

import org.junit.jupiter.api.Test;
import java.util.List;
import static com.datacamp.util.testing.CustomJUnitTestLauncher.launchMockitoTestsAndPrint;
import static org.mockito.Mockito.*;

public class Main {
    public static void main(String[] args) {
        launchMockitoTestsAndPrint(MessageProcessorTest.class);
    }
}

class MessageProcessor {
    private InfoStore infoStore;
    private ErrorStore errorStore;

    public MessageProcessor(InfoStore infoStore, ErrorStore errorStore) {
        this.infoStore = infoStore;
        this.errorStore = errorStore;
    }

    public void process(String message) {
        if (message.startsWith("[INFO]")) infoStore.save(message);
        if (message.startsWith("[ERROR]")) errorStore.save(message);
    }
}

class MessageProcessorTest {

    @Test
    void process_savesNowhere_whenWrongMessageType() {
        InfoStore infoStore = mock(InfoStore.class);
        ErrorStore errorStore = mock(ErrorStore.class);
        MessageProcessor processor = new MessageProcessor(infoStore, errorStore);
        String message = "[WARN] The search is slow.";

        processor.process(message);

        // Verify infoStore was not called
        ____(infoStore);
        // Verify errorStore.save was called 0 times
        verify(errorStore, ____).____(message);
    }
}

interface InfoStore {
    void save(String message);
}
interface ErrorStore {
    void save(String message);
}

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