Add unit tests for StudentManager

tests/test_student_manager.py

@@ -0,0 +1,179 @@
+import pytest
+from datetime import datetime, timedelta
+from student_manager import StudentManager
+
+
+@pytest.fixture
+def student_manager():
+    """Provides a fresh StudentManager for each test."""
+    return StudentManager()
+
+
+class TestAssignments:
+    def test_add_assignment_basic(self, student_manager):
+        deadline = datetime.now() + timedelta(days=5)
+
+        assignment = student_manager.add_assignment("Math HW", deadline, "Math")
+
+        assert assignment in student_manager.assignments
+        assert assignment["title"] == "Math HW"
+        assert assignment["subject"] == "Math"
+        assert assignment["completed"] is False
+
+    def test_add_assignment_with_empty_title(self, student_manager):
+        deadline = datetime.now() + timedelta(days=3)
+
+        assignment = student_manager.add_assignment("", deadline, "Misc")
+
+        # For now we just ensure it is added; behavior can be refined later.
+        assert assignment in student_manager.assignments
+        assert assignment["title"] == ""
+
+    def test_add_assignment_with_null_title(self, student_manager):
+        """Assignment with None as title should still be stored."""
+        deadline = datetime.now() + timedelta(days=3)
+
+        assignment = student_manager.add_assignment(None, deadline, "Misc")
+
+        assert assignment in student_manager.assignments
+        assert assignment["title"] is None
+        assert assignment["completed"] is False
+
+    def test_add_assignment_with_past_deadline(self, student_manager):
+        """Assignments in the past should still be tracked."""
+        past_deadline = datetime.now() - timedelta(days=1)
+
+        assignment = student_manager.add_assignment(
+            "Old HW", past_deadline, "History"
+        )
+
+        assert assignment in student_manager.assignments
+        assert assignment["deadline"] == past_deadline
+        assert assignment["completed"] is False
+
+    def test_list_assignments_empty_collection(self, student_manager):
+        # No assignments added yet
+        assert student_manager.list_assignments() == []
+        assert student_manager.list_assignments(show_completed=True) == []
+
+    def test_list_assignments_shows_only_pending_by_default(self, student_manager):
+        deadline = datetime.now() + timedelta(days=5)
+
+        student_manager.add_assignment("A1", deadline)
+        student_manager.add_assignment("A2", deadline)
+        student_manager.mark_completed("A1")
+
+        pending = student_manager.list_assignments()
+        all_assignments = student_manager.list_assignments(show_completed=True)
+
+        assert len(all_assignments) == 2
+        assert len(pending) == 1
+        assert pending[0]["title"] == "A2"
+
+    def test_mark_completed_existing_assignment(self, student_manager):
+        deadline = datetime.now() + timedelta(days=5)
+
+        student_manager.add_assignment("Physics HW", deadline)
+        result = student_manager.mark_completed("Physics HW")
+
+        assert result is True
+        assert student_manager.assignments[0]["completed"] is True
+
+    def test_mark_completed_non_existent_assignment(self, student_manager):
+        deadline = datetime.now() + timedelta(days=5)
+
+        student_manager.add_assignment("Chem HW", deadline)
+        result = student_manager.mark_completed("Bio HW")  # not present
+
+        assert result is False  # function should indicate failure
+
+    def test_mark_completed_with_duplicate_titles(self, student_manager):
+        deadline = datetime.now() + timedelta(days=5)
+
+        student_manager.add_assignment("Project", deadline)
+        student_manager.add_assignment("Project", deadline)
+
+        result = student_manager.mark_completed("Project")
+
+        assert result is True
+        # At least one of them should be completed
+        completed_count = sum(1 for a in student_manager.assignments if a["completed"])
+        assert completed_count >= 1
+
+
+class TestUpcomingDeadlines:
+    def test_upcoming_deadlines_future_assignment(self, student_manager):
+        future_deadline = datetime.now() + timedelta(days=3)
+
+        student_manager.add_assignment("Task1", future_deadline)
+
+        upcoming = student_manager.get_upcoming_deadlines(days=7)
+
+        assert len(upcoming) == 1
+        assert upcoming[0]["title"] == "Task1"
+        # days_remaining and priority are added by get_upcoming_deadlines
+        assert "days_remaining" in upcoming[0]
+        assert "priority" in upcoming[0]
+
+    def test_upcoming_deadlines_excludes_past_deadline(self, student_manager):
+        past_deadline = datetime.now() - timedelta(days=2)
+
+        student_manager.add_assignment("Old Task", past_deadline)
+
+        upcoming = student_manager.get_upcoming_deadlines(days=7)
+
+        # Past tasks should not appear in upcoming deadlines
+        assert upcoming == []
+
+
+class TestGradesAndGPA:
+    def test_add_grade_valid(self, student_manager):
+        student_manager.add_grade("Math", 90)
+
+        assert len(student_manager.grades) == 1
+        assert student_manager.grades[0]["subject"] == "Math"
+        assert student_manager.grades[0]["grade"] == 90
+
+    def test_add_grade_negative_value(self, student_manager):
+        with pytest.raises(ValueError):
+            student_manager.add_grade("Math", -10)
+
+    def test_add_grade_above_max_value(self, student_manager):
+        with pytest.raises(ValueError):
+            student_manager.add_grade("Math", 150)
+
+    def test_calculate_gpa_with_multiple_grades(self, student_manager):
+        student_manager.add_grade("Math", 80)
+        student_manager.add_grade("English", 90)
+        student_manager.add_grade("Science", 70)
+
+        # Average is (80 + 90 + 70) / 3 = 80
+        assert student_manager.calculate_gpa() == pytest.approx(80.0)
+
+    def test_calculate_gpa_with_no_grades(self, student_manager):
+        assert student_manager.calculate_gpa() == 0.0
+
+
+class TestStatistics:
+    def test_statistics_with_no_data(self, student_manager):
+        stats = student_manager.get_statistics()
+
+        assert stats["total_assignments"] == 0
+        assert stats["completed"] == 0
+        assert stats["pending"] == 0
+        assert stats["gpa"] == 0.0
+
+    def test_statistics_with_assignments_and_grades(self, student_manager):
+        deadline = datetime.now() + timedelta(days=5)
+
+        student_manager.add_assignment("Chem", deadline)
+        student_manager.add_assignment("Bio", deadline)
+        student_manager.mark_completed("Chem")
+        student_manager.add_grade("Chem", 90)
+
+        stats = student_manager.get_statistics()
+
+        assert stats["total_assignments"] == 2
+        assert stats["completed"] == 1
+        assert stats["pending"] == 1
+        assert stats["gpa"] == 90