Integration lane caught it (run 2984): the backfill reported 0 rows to fill
and left `data` unset. `IS NULL` was the whole predicate, but a JSONB column
has two empty states. SQLAlchemy's JSON types default to
`none_as_null=False`, so assigning Python `None` persists the JSON encoding
of null — `IS NULL` walks straight past it.
Migration 0070 left genuine SQL NULLs, so the product path was right; the
test was constructing the wrong shape with `data=None`. Fixed both ways,
because both states mean "no usable mirror":
- predicate is now `data IS NULL OR jsonb_typeof(data) = 'null'`;
- the legacy-row test OMITS `data` (a real SQL NULL, 0070's actual shape),
and a second test covers the JSON-null shape and asserts the premise with
`jsonb_typeof` rather than assuming it.
Refs #2083.
"What canonical helpers already live in this file?" was unanswerable:
location lived only in the body markdown. It is now a jsonpath containment
query over the `notes.data` mirror added by migration 0070.
- One predicate in two dialects in services/knowledge.py: SQL (`data @?`,
applied in the browse arm and the keyword arm before count/pagination, so
totals stay honest) and Python (`location_matches`, for the semantic arm
which post-filters candidates it already holds). Both must change together.
- Parts are ANDed within a SINGLE locations entry — repo A in one entry and
path B in another is not "recorded at A/B". `path` also matches as a
directory prefix, via jsonpath `starts with` rather than `@>`, which the
same GIN index serves.
- `repo`/`path`/`symbol` reach the service, the REST list and the MCP tool
under one name with one default (rule #33); the MCP docstring teaches the
place form, and so does the reusing-code skill (plugin.json bumped).
- UI: a Location disclosure beside the snippet search, with its own empty
state — "nothing kept there, so what you're about to write is new."
Settles #2083's open question (pre-0070 NULL `data`) by backfilling after
all: `backfill_snippet_data` runs at startup, deriving the mirror from the
body with the same parser the read path trusts. 0070's caution was about
mangling a hand-edited body; this never touches the body. The alternative
was a permanent second body-regex arm, or a query that silently answers
"nothing here" for an old snippet and gets the helper written twice.
Refs #2083, milestone #232.
bvandeusen