ros2-assignments/doc/tests/FinalGradeDeterminator.md

Final Grade Determintator Node Unit Tests

Unit tests for FinalGradeDeterminator are implemented in src/g2_2025_grade_calculator_pkg/test/FinalGradeDeterminator.test.cpp using Google Test and ROS2 test utilities. The tests use a mock database manager and a mock grade calculator service to simulate the node's interactions.

Test Cases

1. ConstructorTest

Description: Verifies that the node can be constructed without errors.

• Input: Construct a FinalGradeDeterminator node.
• Expected Output: No exceptions are thrown. The node is created successfully.

2. ExamCollectionTest

Description: Sends the required number of exam results and checks that a grade calculation request is triggered, a student message is published, and the results are stored.

• Input:
  • Student: "Test Student"
  • Course: "Test Course"
  • Grades published: [80, 85, 90, 75, 95] (5 exam results, which is the default required amount)
• Expected Output:
  • A grade calculation service request is made with the correct student, course, and grades.
  • A student message is published with the correct student and course.
  • The final grade is calculated as the average: (80 + 85 + 90 + 75 + 95) / 5 = 85.

3. PartialExamCollectionTest

Description: Sends fewer than the required number of exam results and checks that no grade calculation or student message occurs.

• Input:
  • Student: "Test Student"
  • Course: "Test Course"
  • Grades published: [80, 85, 90] (only 3 exam results, less than required)
• Expected Output:
  • No grade calculation service request is made.
  • No student message is published.

4. MultipleStudentsTest

Description: Simulates multiple students submitting exam results and verifies that each student triggers independent grade calculation and messaging.

• Input:
  • Students: "Alice", "Bob"
  • Course: "Test Course"
  • Each student receives grades: [80, 85, 90, 75, 95] (5 exam results per student)
• Expected Output:
  • Two grade calculation service requests are made, one for each student, with the correct grades.
  • Two student messages are published, one for each student.
  • The final grade for each student is calculated as the average: (80 + 85 + 90 + 75 + 95) / 5 = 85.

These tests ensure that the node correctly collects exam results, triggers grade calculation at the right time, publishes the appropriate messages, and interacts with the database as expected.