@Test
  public void testCreateStudent() throws EntityAlreadyExistsException, InvalidParametersException {

    StudentAttributes s = new StudentAttributes();
    s.name = "valid student";
    s.email = "*****@*****.**";
    s.team = "validTeamName";
    s.comments = "";
    s.googleId = "validGoogleId";

    ______TS("fail : invalid params");
    s.course = "invalid id space";
    try {
      studentsDb.createEntity(s);
      Assert.fail();
    } catch (InvalidParametersException e) {
      AssertHelper.assertContains(
          String.format(COURSE_ID_ERROR_MESSAGE, s.course, REASON_INCORRECT_FORMAT),
          e.getMessage());
    }
    LogicTest.verifyAbsentInDatastore(s);

    ______TS("success : valid params");
    s.course = "valid-course";
    studentsDb.createEntity(s);
    LogicTest.verifyPresentInDatastore(s);
    StudentAttributes retrievedStudent = studentsDb.getStudentForGoogleId(s.course, s.googleId);
    assertEquals(true, retrievedStudent.isEnrollInfoSameAs(s));
    assertEquals(null, studentsDb.getStudentForGoogleId(s.course + "not existing", s.googleId));
    assertEquals(null, studentsDb.getStudentForGoogleId(s.course, s.googleId + "not existing"));
    assertEquals(
        null,
        studentsDb.getStudentForGoogleId(s.course + "not existing", s.googleId + "not existing"));

    ______TS("fail : duplicate");
    try {
      studentsDb.createEntity(s);
      Assert.fail();
    } catch (EntityAlreadyExistsException e) {
      AssertHelper.assertContains(
          String.format(StudentsDb.ERROR_CREATE_ENTITY_ALREADY_EXISTS, s.getEntityTypeAsString())
              + s.getIdentificationString(),
          e.getMessage());
    }

    ______TS("null params check");
    try {
      studentsDb.createEntity(null);
      Assert.fail();
    } catch (AssertionError a) {
      assertEquals(Const.StatusCodes.DBLEVEL_NULL_INPUT, a.getMessage());
    }
  }
  private StudentAttributes createNewStudent(String email) throws InvalidParametersException {
    StudentAttributes s = new StudentAttributes();
    s.name = "valid student 2";
    s.course = "valid-course";
    s.email = email;
    s.team = "valid team name";
    s.comments = "";
    s.googleId = "";
    try {
      studentsDb.createEntity(s);
    } catch (EntityAlreadyExistsException e) {
      // Okay if it's already inside
    }

    return s;
  }
  @Test
  public void testUpdateStudent() throws InvalidParametersException, EntityDoesNotExistException {

    // Create a new student with valid attributes
    StudentAttributes s = createNewStudent();
    studentsDb.updateStudent(
        s.course,
        s.email,
        "new-name",
        "new-team",
        "*****@*****.**",
        "new.google.id",
        "lorem ipsum dolor si amet");

    ______TS("non-existent case");
    try {
      studentsDb.updateStudent(
          "non-existent-course",
          "*****@*****.**",
          "no-name",
          "non-existent-team",
          "non.existent.ID",
          "blah",
          "blah");
      signalFailureToDetectException();
    } catch (EntityDoesNotExistException e) {
      assertEquals(
          StudentsDb.ERROR_UPDATE_NON_EXISTENT_STUDENT + "non-existent-course/[email protected]",
          e.getMessage());
    }

    // Only check first 2 params (course & email) which are used to identify the student entry. The
    // rest are actually allowed to be null.
    ______TS("null course case");
    try {
      studentsDb.updateStudent(
          null,
          s.email,
          "new-name",
          "new-team",
          "*****@*****.**",
          "new.google.id",
          "lorem ipsum dolor si amet");
      signalFailureToDetectException();
    } catch (AssertionError a) {
      assertEquals(Const.StatusCodes.DBLEVEL_NULL_INPUT, a.getMessage());
    }

    ______TS("null email case");
    try {
      studentsDb.updateStudent(
          s.course,
          null,
          "new-name",
          "new-team",
          "*****@*****.**",
          "new.google.id",
          "lorem ipsum dolor si amet");
      signalFailureToDetectException();
    } catch (AssertionError a) {
      assertEquals(Const.StatusCodes.DBLEVEL_NULL_INPUT, a.getMessage());
    }

    ______TS("duplicate email case");
    s = createNewStudent();
    // Create a second student with different email address
    StudentAttributes s2 = createNewStudent("*****@*****.**");
    try {
      studentsDb.updateStudent(
          s.course,
          s.email,
          "new-name",
          "new-team",
          s2.email,
          "new.google.id",
          "lorem ipsum dolor si amet");
      signalFailureToDetectException();
    } catch (InvalidParametersException e) {
      assertEquals(
          StudentsDb.ERROR_UPDATE_EMAIL_ALREADY_USED + s2.name + "/" + s2.email, e.getMessage());
    }

    ______TS("typical success case");
    String originalEmail = s.email;
    s.name = "new-name-2";
    s.team = "new-team-2";
    s.email = "new-email-2";
    s.googleId = "new-id-2";
    s.comments = "this are new comments";
    studentsDb.updateStudent(
        s.course, originalEmail, s.name, s.team, s.email, s.googleId, s.comments);

    StudentAttributes updatedStudent = studentsDb.getStudentForEmail(s.course, s.email);
    assertTrue(updatedStudent.isEnrollInfoSameAs(s));
  }