The runtime stylesheet moves to CONFIG_DIR. static/tailwind.min.css is never written again.
━━━ TWO DIFFERENT THINGS WERE SHARING ONE PATH ━━━
static/tailwind.min.css a BUILD ARTEFACT. Committed, image-baked, generated by scanning
the in-tree plugins only. CI's tailwind-fresh check verifies it.
the RUNTIME sheet PER-INSTALL STATE. Additionally scans whatever the user installed
into FEEDBACK_PLUGINS_DIR, so it differs machine to machine.
Writing the second over the first meant that MERELY RUNNING THE DEV SERVER from a git checkout
silently modified a tracked file. `git add -A` then swept a 100KB reshuffle of minified CSS
into the commit and ci/tailwind-fresh went red with a diff that explains nothing — on a PR
whose real change touched no Tailwind classes at all. It also wrote app state into the app
directory, which is read-only in some deploys.
A new route serves the runtime sheet when there is one and falls back to the committed one
otherwise. It is registered BEFORE the /static mount, which would otherwise swallow the path.
━━━ A PERSISTED SHEET MUST NOT OUTLIVE ITS REASON (Codex [P2] x2) ━━━
1. THE USER REMOVES THEIR PLUGINS. Startup only rebuilds when user plugins exist, so nothing
would ever overwrite the stale sheet — and it still carries classes for plugins that are
gone. With no user plugins the COMMITTED sheet is complete by definition. Guarded.
2. THE APP IS UPGRADED, and my first guard for this was WRONG. I compared mtimes. Codex: that
is not a freshness signal across install methods — archives and container images routinely
PRESERVE SOURCE MTIMES, so a just-shipped stylesheet can carry an OLDER timestamp than a
runtime sheet a user built days ago. The mtime check then calls the stale one FRESH and it
masks the new core CSS indefinitely — permanently, if no Tailwind toolchain is present to
trigger a rebuild.
Freshness is decided by CONTENT now. Each runtime build stamps a sidecar with the sha256 of
the committed sheet it was made from. Core ships new CSS -> that file changes -> the hash
changes -> the runtime sheet is correctly judged stale. Timestamps only gesture at the
question that hashing answers.
Falling back to the committed sheet is always safe: at worst it lacks a just-installed plugin's
classes for the seconds until the async rebuild lands.
VERIFIED END TO END. Ran the real dev server with 3 plugins installed: it rebuilt Tailwind over
them (123,291 bytes), wrote the sheet + sidecar to CONFIG_DIR, still served /static/
tailwind.min.css at 200 — and `git diff` on the tracked file came back CLEAN.
8 tests. Bite-tested: reverting to the shared path fails 3, dropping the staleness guards fails
2 more.
pytest 2425, pyflakes 0, Codex 0.
Closes#911
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
