Match the kb folder as a path component in _load_path

[winklemad]

Description

_load_path collects knowledge-base documents by checking rel_path.startswith("kb"). That matches on the name prefix, not the kb/ folder, so any config file or folder whose name merely starts with "kb" is misclassified as a (usually empty) knowledge-base doc and silently dropped:

• kbsettings.yml at the config root → treated as a doc; since it isn't .md, its YAML is never parsed and the config is lost.
• a subfolder such as kbase/ → its .yml config and any .co flows are dropped (the .co is never appended to colang_files).

Meanwhile a genuine kb/doc.md loads fine. The code's own comment already states the intent — "a file in the kb folder".

>>> # a config dir containing kbsettings.yml (sample_conversation: "hi") and kbase/greeting.co
>>> raw_config, colang_files = _load_path(config_dir)
>>> raw_config.get("sample_conversation"), colang_files
(None, [])          # both silently dropped

Fix

Match the kb folder as a path component (kb + os.sep) rather than a name prefix, so only files actually inside kb/ are collected as docs. Genuine kb/ documents are unaffected.

Test Plan

Added test_load_path_kb_prefixed_names_are_not_dropped to tests/test_config_loading.py: a tmp_path config directory with kbsettings.yml, a kbase/ subfolder containing a .co flow, and a genuine kb/doc.md. It asserts the kb-prefixed config file is parsed, the kb-prefixed .co is registered in colang_files, and the real kb/ doc is still collected. Fails on develop, passes with the fix.

$ pytest tests/test_config_loading.py tests/test_railsignore.py tests/test_combine_configs.py tests/test_config_validation.py tests/rails/llm/test_config.py
32 passed

$ ruff check nemoguardrails/rails/llm/config.py tests/test_config_loading.py
All checks passed!
$ ruff format --check nemoguardrails/rails/llm/config.py tests/test_config_loading.py
2 files already formatted

No linked issue — found by reading the code.

[github-actions]

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