Files
TinyTorch/tests
Vijay Janapa Reddi aa310c7b69 test: Add simple pattern learning tests for transformer
Created systematic tests to verify transformer learning on simple tasks:

test_05_transformer_simple_patterns.py:
- Test 1: Constant prediction (always predict 5) → 100% 
- Test 2: Copy task (failed due to causal masking) → Expected behavior
- Test 3: Sequence completion ([0,1,2]→[1,2,3]) → 100% 
- Test 4: Pattern repetition ([a,b,a,b,...]) → 100% 

test_05_debug_copy_task.py:
- Explains why copy task fails (causal masking)
- Tests next-token prediction (correct task) → 100% 
- Tests memorization vs generalization → 50% (reasonable)

Key insight: Autoregressive models predict NEXT token, not SAME token.
Position 0 cannot see itself, so "copy" is impossible. The correct
task is next-token prediction: [1,2,3,4]→[2,3,4,5]

These tests prove the transformer architecture works correctly before
attempting full Shakespeare training.
2025-10-28 09:44:39 -04:00
..

TinyTorch Test Suite

Comprehensive testing organized by purpose and scope.

Test Organization

📦 Module Tests (XX_modulename/)

Purpose: Test individual module functionality
Scope: Single module, isolated behavior
Example: 01_tensor/test_progressive_integration.py

These tests validate that each module works correctly in isolation.

🔗 Integration Tests (integration/)

Purpose: Test cross-module interactions
Scope: Multiple modules working together
Files:

  • test_gradient_flow.py - CRITICAL: Validates gradients flow through entire training stack
  • test_end_to_end_training.py - Full training loops (TODO)
  • test_module_compatibility.py - Module interfaces (TODO)

Why this matters:

  • Catches bugs that unit tests miss
  • Validates the "seams" between modules
  • Ensures training actually works end-to-end

🐛 Debugging Tests (debugging/)

Purpose: Catch common student pitfalls
Scope: Pedagogical - teaches debugging
Files:

  • test_gradient_vanishing.py - Detect/diagnose vanishing gradients (TODO)
  • test_gradient_explosion.py - Detect/diagnose exploding gradients (TODO)
  • test_common_mistakes.py - "Did you forget backward()?" style tests (TODO)

Philosophy: When these tests fail, the error message should teach the student what went wrong and how to fix it.

Autograd Edge Cases (05_autograd/)

Purpose: Stress-test autograd system
Scope: Autograd internals and edge cases
Files:

  • test_broadcasting.py - Broadcasting gradient bugs (TODO)
  • test_computation_graph.py - Graph construction edge cases (TODO)
  • test_backward_edge_cases.py - Numerical stability, etc. (TODO)

Running Tests

All tests

pytest tests/ -v
pytest tests/integration/ -v

Specific test

pytest tests/integration/test_gradient_flow.py -v

Run without pytest

python tests/integration/test_gradient_flow.py

Test Philosophy

  1. Integration tests catch real bugs: The gradient flow test caught the exact bugs that prevented training
  2. Descriptive names: Test names should explain what they test
  3. Good error messages: When tests fail, students should understand why
  4. Pedagogical value: Tests teach correct usage patterns

Adding New Tests

When adding a test, ask:

  • Is it testing one module? → Put in XX_modulename/
  • Is it testing modules working together? → Put in integration/
  • Is it teaching debugging? → Put in debugging/
  • Is it an autograd edge case? → Put in 05_autograd/

Most Important Tests

🔥 Must pass before merging:

  • integration/test_gradient_flow.py - If this fails, training is broken

📚 Module validation:

  • Each module's inline tests (in modules/source/)
  • Module-specific tests in tests/XX_modulename/

Test Coverage Goals

  • All tensor operations have gradient tests
  • All layers compute gradients correctly
  • All activations integrate with autograd
  • All loss functions compute gradients
  • All optimizers update parameters
  • End-to-end training converges (TODO)
  • Common pitfalls are detected (TODO)