fix: address all five open issues (#257, #258, #262, #263, #264)

[antosubash]

Closes#257, closes#258, closes#262, closes#263, closes#264.

Three commits: the five fixes, a follow-up correcting a regression and finishing two fixes that were half done, then a merge of main. This body describes the final state.

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#263 — expression-based index emitted twice under PostgreSQL

The idempotency guard the issue asks for was already in make_process_revision_directives — it just never fired. It scanned only the top level of upgrade_ops.ops, but autogenerate doesn't hand us a flat list: index operations are nested inside a ModifyTableOps group alongside the top-level CreateTableOp. Verified against alembic directly:

UPGRADE:
CreateTableOp users_user
ModifyTableOps users_user
CreateIndexOp users_user ix_users_user_email

So existing_index_names was always empty, the injection re-added an index PostgreSQL had already emitted, and the first make migrate died with DuplicateTable. The scan now recurses through nested op groups; same for DropIndexOp in the downgrade. Name-based and dialect-agnostic, as suggested.

The pre-existing test_does_not_double_inject_when_already_present passed throughout because it built a flat op list — the two new tests use the real nested shape and fail without the fix.

#262 — scaffolded apps migrate the wrong database

Ported this repo's two corrections into the templates:

• templates/host/alembic.ini → script_location = %(here)s/migrations
• templates/workspace/Makefile → migrate/migration run from the repo root

That alone was not enough: smpy new itself still ran the baseline autogenerate and upgrade heads with cwd=host/, so the scaffold's own first migration was the odd one out. It now runs from the project root too, with the ini path collapsing to alembic.ini for the flat create-host layout. env.py also logs the resolved database URL (password masked) so the target is never a guess.

Superseded in part by #267, which landed on main while this was open. That PR did the thing this branch explicitly declined as too broad — find_env_file walks up from the cwd, and relative sqlite URLs anchor to the project root — and it is the better fix. The root cause is now handled centrally; what remains here is the scaffold running everything from one cwd, which keeps the ini path, the .env walk's starting point, and the sqlite file all meaning the same thing. The merge commit rewrites the comments and the bootstrap test that had justified themselves with the old cwd-dependent behaviour, since that is no longer true of the merged tree.

#264 — identical tests/test_module.py basename

Went with your option (1): the template is now tests/test___PACKAGE__.py.tpl, and the existing __PACKAGE__ path-rewrite renders it per module — a module named Alpha gets tests/test_alpha.py. Option (2) is ruled out by an existing comment in the scaffolding tests — a shipped tests/__init__.py makes pytest register tests.conftest twice under importlib mode.

Note one residual: this fixes the scaffolded file, but two modules that later add their own tests/test_service.py would collide the same way. Option (3) (importmode = "importlib" in the workspace template) is the fix for that whole class. I left it out because I can't exercise a scaffolded workspace's pytest run in this environment, and it interacts with the conftest behaviour noted above — happy to add it if you want it.

#257 — get_db commits after the response is sent

Confirmed the mechanism rather than assuming it — with a send-spy around a FastAPI app, teardown ordering is:

• success: ['response.start', 'teardown'] ← the bug
• exception: ['teardown-exception', 'response.start']

Took fix option 1 (commit before the response is sent), so every caller benefits rather than just the one workflow. CommitBeforeResponseMiddleware is pure ASGI and intercepts http.response.start, installed innermost (added first — add_middleware is LIFO). That point is deliberate: late enough that FastAPI has already serialized the response, so committing can't interact with attribute expiry; early enough that nothing has reached the client, so a commit failure can still become a 500.

The first attempt at this had a write-loss bug, caught in review and fixed in the second commit. Finalizing at response.start claimed the session one-shot, but work legitimately continues after that message: Starlette runs BackgroundTasks once the body is sent, and a StreamingResponse writes its body afterwards — both on the same session. Those writes flushed and never committed, and get_db's fallback no-op'd because the session was already claimed. Reproduced: a background task adding a row persisted nothing with the middleware and persisted correctly without it.

finalize_session is now re-armable rather than one-shot — each call commits whatever is pending at that moment, and get_db's exit code still runs to catch work done after the response started. The pending-write marker is cleared on settle so a committed session is never re-committed, and a failed commit is settled too so the fallback cannot retry it. Read-only requests still pay for exactly one rollback. The error path is unchanged: FastAPI unwinds the dependency — rolling back — before the error response is sent.

An APIRoute subclass was the other candidate and was rejected: FastAPI 0.141 includes routers lazily via _IncludedRouter, so a route_class set on app.router no longer propagates to included module routers.

Known limitation, documented in the middleware: with more than one enlisted session (Depends(get_db, use_cache=False)), a failure part-way leaves earlier commits durable while the client sees a 500. No cross-session atomicity short of two-phase commit.

#258 — gen-pages omits wheel modules' components/

Same CSS fix as your PR #259 — that PR is still open, so this branch carries its own copy; drop whichever lands second. components/ now gets an absolute @source exactly as pages/ does, and appears in modules.assets.json. In-repo modules stay covered by the host's static glob.

That was also only half the fix. Vite's bare-specifier fallback resolver only fires for importers under a module's pages/ prefix, so a wheel widget's @simple-module-py/ui import still died with "Failed to resolve import" — the classes were compiled but the component couldn't build. components/ now contributes its prefix and an optimizeDeps entry too, in the host and in the scaffold template.

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Notes on test honesty

• test_created_row_is_readable_on_the_very_next_request documents the client-visible contract but does not fail without the fix — httpx's in-process ASGI transport awaits the full request, teardown included, before issuing the next one, so the follow-up can never lose the race there. The real regression guard is test_write_is_durable_before_the_response_is_delivered. Both docstrings say so.
• test_commit_failure_becomes_a_500 originally stubbed finalize_session, bypassing its bookkeeping, so get_db's fallback committed the very row the test called lost — it asserted only the status code and would have passed with the guarantee broken. It now injects at AsyncSession.commit and asserts the table is empty.

Merge with main

main moved (#266, #267) and the PR went conflicted. One file conflicted: the scaffold's vite.config.ts. Both sides had restructured it for the same reason — the 300-line cap — main extracting vite.dev-url.ts, this branch extracting module-assets.ts. Kept both extractions; taking main's inline asset block would also have dropped this branch's components/ support.

Splitting the scaffold's vite.config.ts mirrors the split the host already made. The migration-bootstrap tests moved to their own file on the same grounds.

Verification (on the merged tree)

• pytest: 2016 passed, 2 skipped
• vitest: 48 passed · biome ci .: clean · tsc --noEmit: clean
• ruff format --check + ruff check + ty check: clean
• 300-line file cap: clean

Each fix's regression test was run against the unpatched code to confirm it actually fails, except where noted above. Generated frontend files are gitignored, so there's nothing to regenerate.

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