text: import unittest
  
  from grade_school import (
      School,
  )
  
  # Tests adapted from `problem-specifications//canonical-data.json`
  
  
  class GradeSchoolTest(unittest.TestCase):
      def test_roster_is_empty_when_no_student_is_added(self):
          school = School()
          expected = []
  
          self.assertEqual(school.roster(), expected)
  
      def test_add_a_student(self):
          school = School()
          school.add_student(name="Aimee", grade=2)
          expected = [True]
          self.assertEqual(school.added(), expected)
  
      def test_student_is_added_to_the_roster(self):
          school = School()
          school.add_student(name="Aimee", grade=2)
          expected = ["Aimee"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_adding_multiple_students_in_the_same_grade_in_the_roster(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="Paul", grade=2)
          expected = [True, True, True]
          self.assertEqual(school.added(), expected)
  
      def test_multiple_students_in_the_same_grade_are_added_to_the_roster(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="Paul", grade=2)
          expected = ["Blair", "James", "Paul"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_cannot_add_student_to_same_grade_in_the_roster_more_than_once(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="Paul", grade=2)
          expected = [True, True, False, True]
          self.assertEqual(school.added(), expected)
  
      def test_a_student_can_t_be_in_two_different_grades(self):
          school = School()
          school.add_student(name="Aimee", grade=2)
          school.add_student(name="Aimee", grade=1)
          expected = []
          self.assertEqual(school.roster(2), expected)
  
      def test_a_student_can_only_be_added_to_the_same_grade_in_the_roster_once(self):
          school = School()
          school.add_student(name="Aimee", grade=2)
          school.add_student(name="Aimee", grade=2)
          expected = ["Aimee"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_student_not_added_to_same_grade_in_the_roster_more_than_once(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="Paul", grade=2)
          expected = ["Blair", "James", "Paul"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_adding_students_in_multiple_grades(self):
          school = School()
          school.add_student(name="Chelsea", grade=3)
          school.add_student(name="Logan", grade=7)
          expected = [True, True]
          self.assertEqual(school.added(), expected)
  
      def test_students_in_multiple_grades_are_added_to_the_roster(self):
          school = School()
          school.add_student(name="Chelsea", grade=3)
          school.add_student(name="Logan", grade=7)
          expected = ["Chelsea", "Logan"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_cannot_add_same_student_to_multiple_grades_in_the_roster(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=3)
          school.add_student(name="Paul", grade=3)
          expected = [True, True, False, True]
          self.assertEqual(school.added(), expected)
  
      def test_a_student_cannot_be_added_to_more_than_one_grade_in_the_sorted_roster(
          self,
      ):
          school = School()
          school.add_student(name="Aimee", grade=2)
          school.add_student(name="Aimee", grade=1)
          expected = ["Aimee"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_student_not_added_to_multiple_grades_in_the_roster(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=3)
          school.add_student(name="Paul", grade=3)
          expected = ["Blair", "James", "Paul"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_students_are_sorted_by_grades_in_the_roster(self):
          school = School()
          school.add_student(name="Jim", grade=3)
          school.add_student(name="Peter", grade=2)
          school.add_student(name="Anna", grade=1)
          expected = ["Anna", "Peter", "Jim"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_students_are_sorted_by_name_in_the_roster(self):
          school = School()
          school.add_student(name="Peter", grade=2)
          school.add_student(name="Zoe", grade=2)
          school.add_student(name="Alex", grade=2)
          expected = ["Alex", "Peter", "Zoe"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_students_are_sorted_by_grades_and_then_by_name_in_the_roster(self):
          school = School()
          school.add_student(name="Peter", grade=2)
          school.add_student(name="Anna", grade=1)
          school.add_student(name="Barb", grade=1)
          school.add_student(name="Zoe", grade=2)
          school.add_student(name="Alex", grade=2)
          school.add_student(name="Jim", grade=3)
          school.add_student(name="Charlie", grade=1)
          expected = ["Anna", "Barb", "Charlie", "Alex", "Peter", "Zoe", "Jim"]
  
          self.assertEqual(school.roster(), expected)
  
      def test_grade_is_empty_if_no_students_in_the_roster(self):
          school = School()
          expected = []
          self.assertEqual(school.grade(1), expected)
  
      def test_grade_is_empty_if_no_students_in_that_grade(self):
          school = School()
          school.add_student(name="Peter", grade=2)
          school.add_student(name="Zoe", grade=2)
          school.add_student(name="Alex", grade=2)
          school.add_student(name="Jim", grade=3)
          expected = []
          self.assertEqual(school.grade(1), expected)
  
      def test_student_not_added_to_same_grade_more_than_once(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="Paul", grade=2)
          expected = ["Blair", "James", "Paul"]
          self.assertEqual(school.grade(2), expected)
  
      def test_student_not_added_to_multiple_grades(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=3)
          school.add_student(name="Paul", grade=3)
          expected = ["Blair", "James"]
          self.assertEqual(school.grade(2), expected)
  
      def test_student_not_added_to_other_grade_for_multiple_grades(self):
          school = School()
          school.add_student(name="Blair", grade=2)
          school.add_student(name="James", grade=2)
          school.add_student(name="James", grade=3)
          school.add_student(name="Paul", grade=3)
          expected = ["Paul"]
          self.assertEqual(school.grade(3), expected)
  
      def test_students_are_sorted_by_name_in_a_grade(self):
          school = School()
          school.add_student(name="Franklin", grade=5)
          school.add_student(name="Bradley", grade=5)
          school.add_student(name="Jeff", grade=1)
          expected = ["Bradley", "Franklin"]
          self.assertEqual(school.grade(5), expected)
  