feat: add opt-in strict chunk_index validation

[rbcorrales]

Summary

Adds an opt-in strict mode to REST::insert_embedding_row(). When the wpvdb_strict_chunk_index filter returns true, a null, non-numeric, or negative chunk_index is rejected with a WP_Error (chunk_index_invalid, status 400) instead of silently defaulting to 0.

Background

062a942 gave chunk_index a null default plus a WP_DEBUG warning, then falls back to 0. That silent fallback is exactly the class of regression that produced the original all-chunk_index=0 corpus bug. Strict mode lets a site (or CI) opt into failing loudly so a caller passing a bad chunk_index is caught immediately.

Default behavior is unchanged: the filter defaults to false, so the legacy warn-then-default-to-0 path runs byte-for-byte as before. The new branch mirrors the existing embedding_invalid validation right below it (same Logger::error + WP_Error shape with status => 400).

Testing

php -l clean. phpcs --standard=phpcs.xml.dist introduces zero new violations (15 errors / 18 warnings before and after, all pre-existing baseline in this file). Default path untouched; only the new filter-gated branch is added.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds an opt-in “strict mode” validation path to REST::insert_embedding_row() to prevent silently defaulting invalid chunk_index values to 0, helping catch caller regressions early while preserving current default behavior.

Changes:

• Introduces wpvdb_strict_chunk_index filter (default false) to gate strict validation.
• When strict mode is enabled, rejects chunk_index values that are null, non-numeric, or negative with a WP_Error (chunk_index_invalid, status 400).
• Keeps existing warn-and-default-to-0 behavior unchanged when strict mode is disabled.

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[rbcorrales]

Follow-up updates pushed in c4c5a01 and 5cddfd3.

These tighten the strict chunk index contract, expand REST coverage for edge cases and strict-off behavior, and add the bootstrap shims needed for the unit suite to run cleanly.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

[rbcorrales]

Independently re-validated the whole PR before merge:

Tests: composer test:unit is green: 135 tests, 530 assertions, OK (includes the strict on / off / invalid RESTTest cases).

Feature (insert_embedding_row, class-wpvdb-rest.php:925-950): valid chunk_index = is_int and >= 0, or a ^\d+$ string within PHP_INT_MAX. Strict + invalid returns WP_Error( 'chunk_index_invalid', ..., 400 ). The default (non-strict) path is unchanged: null still warns and falls back to 0. Confirmed it correctly rejects floats and out-of-range values, which the original looser is_numeric check would have accepted.

Copilot review points, all verified in code:

• accepted_args = 0 honored: tests/bootstrap.php:83-84 clamps max( 0, ... ) and array_slice( ..., 0, $accepted_args ), so a zero-arg callback is invoked with no args.
• per-test filter reset: tests/filter-reset-hook.php (Before/After test hooks) registered as a phpunit extension; no cross-test leakage.
• RESTTest zero-arg closures: registered with add_filter( ..., 10, 0 ) (RESTTest.php:29,65).
• remove_filter cleanup: tests/bootstrap.php:50-55 unsets empty priority and tag buckets so has_filter() reports correctly.

Pre-existing note (not introduced here): composer test (all suites) errors because the api testsuite in phpunit.xml points at a non-existent tests/api dir. That is also present on main; composer test:unit is the working path. Worth a separate cleanup.

Mergeable and CLEAN.

[rbcorrales]

Folded a phpunit.xml fix (3d9bc8) into this PR rather than spinning a separate one, since this PR already owns the test-infrastructure changes.

Removed the api testsuite, which pointed at a non-existent tests/api directory and made composer test abort with Test directory tests/api not found before any suite ran (this was also true on main). composer test now executes the suites: unit is green (135 tests, 530 assertions), and integration runs as before (it needs a real DB/WP, so it skips or fails in a no-DB local run; that is unchanged and out of scope here). composer test:unit remains the clean no-DB path.