coyote/docs/testing/notes/ITERATION-12-NOTES.md

Iteration 12 — Test Implementation Notes

Plan file addressed

docs/testing/plans/12-rag.md

Tests created

src/rag/mod.rs (22 new tests)

Test name	What it verifies
document_id_round_trip	new(5,17) → split → (5,17)
document_id_zero_zero	new(0,0) → split → (0,0)
document_id_large_values	new(1000,9999) round-trips
document_id_debug_format	Debug produces "3-7" format
document_id_equality	Same file+doc → equal
document_id_inequality	Different doc → not equal
document_id_ordering	(0,1) < (1,0)
rag_document_new	Sets page_content, empty metadata
rag_document_default	Empty content and metadata
rag_data_new_defaults	All fields set correctly
rag_data_get_returns_document	Gets by file+doc index
rag_data_get_returns_none_for_missing_file	Missing file → None
rag_data_get_returns_none_for_missing_document	Missing doc index → None
rag_data_del_removes_files_and_vectors	Del removes both
rag_data_del_nonexistent_is_noop	Del missing → noop
rag_data_add_inserts_files_and_vectors	Add inserts files+vectors, updates next_file_id
rag_template_contains_placeholders	CONTEXT, SOURCES, INPUT present
get_separators_returns_language_specific	rs/py/md have language separators
get_separators_unknown_returns_defaults	xyz → DEFAULT_SEPARATORS
get_separators_all_known_extensions	All 22 known extensions differ from defaults
rag_data_build_bm25_empty	Empty data → no search results
rag_data_build_bm25_finds_documents	BM25 finds "rust" in first doc

Total: 22 new tests (440 total in suite)

Bugs discovered

None.

Observations for future iterations

1. Rag struct can't be constructed without an embedding model: Rag::init requires prompting the user for model selection, Rag::load requires a YAML file on disk, and Rag::create requires pre-built RagData with vectors. All RAG lifecycle operations are I/O-bound.

2. DocumentId uses bit packing: file_index in the upper half, document_index in the lower half of a usize. This is tested with round-trip, zero, and large-value cases.

3. RagData operations (get/del/add) are fully testable: These are pure data structure operations that don't need I/O. The BM25 search engine can also be built and queried in tests.

4. The text splitter already has comprehensive tests: 5 existing tests cover split_text, create_documents, chunk headers, markdown splitting, and HTML splitting. No additional splitter tests needed.

5. get_separators covers 22 language extensions: All are verified to return language-specific separators rather than defaults. This ensures the splitter uses appropriate chunk boundaries for each language.

Next iteration

Plan file 13: Completions and Prompt — tab completion, prompt rendering, highlighter.