Splitting style.css deleted it, and two files outside static/ still
named it:
- scripts/verify_background_research_cards.mjs injected
`<link rel="stylesheet" href="/static/style.css">` into the page it
builds. A stylesheet that 404s does not fail — the script kept
checking card layout against an unstyled page and kept reporting
pass. It now reads the shell's <link> tags out of index.html, the way
tests/css_snapshot/capture.mjs already does, so the set cannot drift
out from under it again.
- tests/css_snapshot/bench.html's hand-open fallback linked the same
deleted file. Replaced with the ordered set index.html ships.
test_every_stylesheet_referenced_by_shipped_html_exists only walked
static/*.html, which is why neither showed up. Extend it over the bench
page: the bench's whole output is computed styles, so a dead link there
is worth more than an unstyled page nobody looks at.
static/style.css was 47,530 lines. It is now nine files under static/css/:
tokens.css holds the :root custom properties, light theme and density classes,
and style-part-01..08 carry the rest in their original order. Nothing was
rewritten; every line moved verbatim and the <link> order in index.html
reproduces the original file byte for byte.
Cut points are brace-depth zero and outside block comments, so no rule or
comment is split. All 47,531 source lines are accounted for across the
fragments.
The computed-style baseline recorded before the split is reproduced exactly,
which is the evidence that the cascade is unchanged rather than an argument
that it should be.
Three things the split broke and this fixes:
- The harness self-test swapped two conflicting .attach-strip blocks inside
style.css to prove the digest is order-sensitive. It rewrote one hardcoded
URL, so with the file gone it silently measured an unmodified page. It now
searches every stylesheet, rewrites whichever holds the pair, and fails
loudly if none does.
- Four tests asserted the cache-bust token by matching /static/style.css?v=.
They check the real invariant now, that every app stylesheet shares one
token with app.js, through stylesheet_cache_version().
- The three panel stylesheets carried their own tokens, so a browser could
hold half an old cascade and half a new one. All app stylesheets now bust
together.
static/style.css is 51,425 lines in one file. Hundreds of selectors are
declared more than once and !important is used throughout, so the rendered
result is a function of source order. Extracting a block into its own file
changes that order, and nothing in the suite would notice - which makes a
51k-line split unfalsifiable and "looks fine to me" the only available
evidence.
This moves no CSS. It captures getComputedStyle over a fixed inventory of
676 elements across three pages, four viewports, both themes and the three
density modes - 16,224 element snapshots - hashes them, and compares against
tests/css_snapshot/baseline.json. A capture takes about 21 seconds.
The bench page synthesises one element per selector from an evidence-driven
list: every selector declared more than once in style.css that can be
expressed as a static compound chain, plus a curated set per feature area.
Redeclared selectors are the ones a reorder can flip. The bench loads
whatever stylesheets index.html ships, so it keeps measuring the real set
once the file is split. tests/test_css_computed_style_snapshot.py also carries
a self-test that swaps two conflicting .attach-strip declarations and asserts
the digest moves, so the harness cannot silently stop watching.
The second half is the asset-manifest check specs/frontend.md asks for,
scoped to stylesheets: every stylesheet referenced by shipped HTML and by the
sw.js precache exists, and index.html and sw.js agree on the ?v= string. They
hardcode it independently today, so a split that updates one and not the
other ships an offline cache nobody notices until a plane.
Alexandre Teixeira