如何在Android的JUnit测试用例中获取MainActivity的上下文和活动？

Question

I am creating a simple quiz application where the user answers five questions and a result is toasted onto the screen. In my MainActivity, I call the constructor of a questionsMethods class with parameters context and activity.

My question is: How do I get the context and activity of MainActivity in a JUnit test class? I need this because the methods in questionsMethods make use of context and activity.

Part of the code: MainActivity:

    public class MainActivity extends AppCompatActivity {
        questionsMethods myQuestionMethods = new questionsMethods(this, this);
        private String[] questionArray = new String[30]; // Holds text file
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            AssetManager assetManager = getAssets();

            myQuestionMethods.readWriteFile("listofquestions.txt", questionArray); // Reads from text file into array

questionsMethods:

public class questionsMethods {
private Context mContext;
    private Activity mActivity;
    private int localCounterForCurrQuestionCount = 1;
    private String[] localQuestionsArray = new String[30];     

    public questionsMethods(Context context, Activity activity) {
        mContext = context;
        mActivity = activity;
    }

public void readWriteFile(String fileName, String[] questionArray) {
    int count = 0; // Holds count of array index in which a line is stored
    try {
        String nextLine;
        InputStream is = mContext.getAssets().open(fileName); // Retrieves and opens fileName
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
        while ((nextLine = bufferedReader.readLine()) != null) { // Check if line incrementer reaches the end
            questionArray[count] = nextLine;
            count++;
        }
    } catch (java.io.IOException ex) {
        Log.i("Error", "Cannot read file");
        System.exit(1);
    }
    localQuestionsArray = questionArray;
}

Answer 1

Use Robolectric, however your code is very hard to test. The QuestionMethods class is only responsible for business logic and should not depend on Android.

So if you want to make your code cleaner and you want to test QuestionMethods properly, Robolectric should not be used for classes that are responsible for business logic.