I keep getting the following error when running my Espresso tests:
Attempt to invoke virtual method 'android.content.Context android.app.Instrumentation.getTargetContext()' on a null object reference
@RunWith(AndroidJUnit4.class)
public class TestLogin extends AndroidTestCase {
@Rule
public ActivityTestRule<MainActivity> mActivityRule = new ActivityTestRule<>(MainActivity.class);
@Test
public void testVerifyCredentials() {
Context context = this.getContext().getApplicationContext();
SharedPreferences prefs = context.getSharedPreferences("current.user", Context.MODE_PRIVATE);
assertTrue(prefs.getBoolean("IsLoggedIn", false));
}
}
I already tried this as an InstrumentationTestCase, and then tried instead to do Context context = this.getInstrumentation().getTargetContext().getApplicationContext(); but that still lead to the NPE.
What am I doing wrong?
The SessionManager class I'm using in my application to manage SharedPrefs:
package com.nullpointexecutioners.buzzfilms.helpers;
import android.content.Context; import android.content.SharedPreferences;
import com.firebase.client.Firebase; import com.nullpointexecutioners.buzzfilms.Major;
/**
* Helper class for managing a session (i.e. persistence across launches of the app
*/
public class SessionManager {
private static SessionManager sInstance;
private final SharedPreferences pref;
private final SharedPreferences.Editor editor;
//SharedPref file name
private static final String PREF_NAME = "current.user";
//All Shared Preferences Keys
private static final String IS_LOGIN = "IsLoggedIn";
//Username
public static final String KEY_USERNAME = "username";
//Name
public static final String KEY_NAME = "name";
//Email
public static final String KEY_EMAIL = "email";
//Major
public static final String KEY_MAJOR = "major";
//is an Admin
public static final String IS_ADMIN = "isAdmin";
final Firebase mRef = new Firebase("redacted");
/**
* Constructor for instance of SessionManager
* @param context of session
* @return instance of SessionManager
*/
public static SessionManager getInstance(Context context) {
if (sInstance == null) {
sInstance = new SessionManager(context);
}
return sInstance;
}
/**
* Constructor for SessionManager class
* @param context of session
*/
private SessionManager(Context context) {
pref = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
editor = pref.edit();
}
/**
* Create login session
* @param username to store in SharedPrefs
* @param name name of a user
* @param email to store in SharedPrefs
* @param major major of a user
* @param isAdmin determines if a user is admin or not
*/
public void createLoginSession(String username, String name, String email, String major, boolean isAdmin) {
/*Store each value into SharedPrefs*/
editor.putBoolean(IS_LOGIN, true);
editor.putString(KEY_USERNAME, username);
editor.putString(KEY_NAME, name);
editor.putString(KEY_EMAIL, email);
if (major.equals(Major.NONE.toString())) {
editor.putString(KEY_MAJOR, "NONE");
} else {
editor.putString(KEY_MAJOR, major);
}
editor.putBoolean(IS_ADMIN, isAdmin);
//Commit changes to SharedPrefs
editor.apply();
}
/**
* Update the current Session's values
* @param name to update
* @param email to update
* @param major to update
*/
public void updateSession(String name, String email, String major) {
/*Store the updated values into SharedPrefs*/
editor.putString(KEY_NAME, name);
editor.putString(KEY_EMAIL, email);
if (major.equals(Major.NONE.toString())) {
editor.putString(KEY_MAJOR, "NONE");
} else {
editor.putString(KEY_MAJOR, major);
}
//Commit changes to SharedPrefs
editor.apply();
}
/**
* Checks if current user is logged in
* If false, the user is redirected to WelcomeActivity to login or register
* @return true or false depending if we're logged in
*/
public boolean checkLogin() {
return pref.getBoolean(IS_LOGIN, false);
}
/**
* Checks if current user is an Admin
* If false, the user won't have access to Admin functions
* @return true or false depending if the user is an Admin
*/
public boolean checkAdmin() {
return pref.getBoolean(IS_ADMIN, false);
}
/**
* Getter for currently logged in user's username
* @return current user's username
*/
public String getLoggedInUsername() {
String username = null;
if (pref.contains(KEY_USERNAME) && pref.getBoolean(IS_LOGIN, false)) {
username = pref.getString(KEY_USERNAME, null);
}
return username;
}
/**
* Getter for currently logged in user's name
* @return current user's name
*/
public String getLoggedInName() {
String name = null;
if (pref.contains(KEY_NAME) && pref.getBoolean(IS_LOGIN, false)) {
name = pref.getString(KEY_NAME, "name");
}
return name;
}
/**
* Getter for currently logged in user's email
* @return current user's email
*/
public String getLoggedInEmail() {
String email = null;
if (pref.contains(KEY_EMAIL) && pref.getBoolean(IS_LOGIN, false)) {
email = pref.getString(KEY_EMAIL, null);
}
return email;
}
/**
* Getter for currently logged in user's major
* @return current user's major
*/
public String getLoggedInMajor() {
String major = null;
if (pref.contains(KEY_MAJOR) && pref.getBoolean(IS_LOGIN, false)) {
major = pref.getString(KEY_MAJOR, null);
}
return major;
}
/**
* Clears session credentials
*/
public void logoutUser() {
//UnAuth from Firebase
mRef.unauth();
//Clear SharedPrefs and set IS_LOGIN to false
editor.clear();
editor.putBoolean(IS_LOGIN, false);
editor.commit();
}
/**
* Getter for accessing the current SharedPrefs
* @return this session's SharedPrefs
*/
public SharedPreferences getPref() {
return pref;
}
}
