SQLite creates the database FILE on demand but never its parent DIRECTORY, and
SqliteLocalDb opens the file eagerly in its constructor — so a configured path
under a not-yet-existing directory was a hard startup failure ("SQLite Error
14: unable to open database file") rather than a first run that just worked.
Relative defaults like ./data/app.db hit it routinely; a containerized consumer
escapes only when a volume mount happens to create the directory first.
ScadaBridge found this during LocalDb Phase 2 and worked around it app-side
(SiteLocalDbDirectory.Ensure). Every other consumer still had the gap, so the
guarantee belongs here.
The standing objection to a library that creates directories is that it can
mask a mis-typed path by silently starting an empty database. That does not
apply: SQLite ALREADY does exactly that for a mis-typed file NAME. Refusing to
create the directory protects nothing — it only makes the two halves of one
path behave inconsistently and turns the directory half into an opaque error.
A creation failure (permissions, read-only mount) now throws an
InvalidOperationException naming the directory and the cause, instead of
surfacing as SQLite error 14. That is a change of exception type, but only on a
path that already failed hard.
Both behaviours are pinned and verified to fail with the call removed.
147 tests pass, 0 warnings. Published to the Gitea feed at 0.1.1.
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
Joseph Doherty
12e6f0d2c5