test: replace broken test suite with 52 passing tests

[utkarshqz]

Description

Replaces the broken test suite with 52 fully passing tests covering the LLM class, template endpoints, and form endpoints.

The existing test infrastructure had two critical problems:

1. test_templates.py sent JSON to a multipart/form-data endpoint → always 422
2. test_forms.py was entirely commented out → zero coverage
3. conftest.py used session-scoped DB → tests leaked data into each other

This PR fixes all three and adds comprehensive tests for the new functionality introduced alongside it.

Fixes #163
Fixes #182
Fixes #183
Closes #186

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

python -m pytest tests/ -v

Output:

52 passed, 14 warnings in 0.58s

All 52 tests pass on Windows 11, Python 3.11, in a clean virtual environment.

Test breakdown:

tests/test_llm.py — 15 tests (new file, Closes #186)

• TestTypeCheckAll — validates input types correctly
• TestBuildBatchPrompt — confirms human labels appear in prompt
• TestBuildPrompt — role-based guidance for officer/victim/location fields
• TestHandlePluralValues — semicolon splitting, whitespace stripping
• TestAddResponseToJson — stores values, ignores -1, handles plurals
• TestMainLoop — mocked Ollama, asserts exactly 1 API call (O(1) batch)

tests/test_templates.py — 10 tests (replaces broken version)

• Upload valid PDF → 200
• Upload without file → 422
• Upload non-PDF → 400
• List templates → 200, returns list, empty on fresh DB
• Get by ID → 200 with correct data
• Get non-existent → 404
• Get invalid ID type → 422

tests/test_forms.py — 7 tests (replaces commented-out version)

• Fill with missing template → 404
• Fill with missing fields → 422
• Fill with Ollama down → 503
• Get submission not found → 404
• Get submission invalid ID → 422
• Download not found → 404
• Download with missing file on disk → 404

tests/conftest.py — fixed DB isolation

• Changed from session-scoped to function-scoped (autouse=True)

• Each test gets a fresh empty DB — no data leakage between tests

• Added db_session fixture for direct DB access in test setup

• Test A — python -m pytest tests/ -v → 52 passed

• Test B — ran twice consecutively, same result (no order dependency)

Test Configuration:

• OS: Windows 11
• Python: 3.11.9
• pytest: 9.0.2

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules