The old rule used a fixed 8px floor on minPad, which produced false
positives on small inline pills (like the homepage's .detection-cmd
at 6px vertical / 14px horizontal on 13px font) and false negatives
on large text (a 24px heading with 8px padding all around passed
the floor but is genuinely too tight for the text size).
The new rule uses two independent axis thresholds that scale with
font-size:
vertical: max(4px, fontSize × 0.3)
horizontal: max(8px, fontSize × 0.5)
The asymmetry reflects typographic reality: line-height already
provides built-in vertical breathing room (the line box is taller
than the cap height), so vertical padding can be tighter than
horizontal. Both thresholds scale with font-size — bigger text
demands proportionally more padding.
Behavior changes
- Small inline pills with line-height-aware padding now pass
(.detection-cmd: V 6 ≥ 4, H 14 ≥ 8). The homepage CSS is unchanged.
- Cramped large text now flags (24px heading with 8px padding fails
H 8 < 12). The old rule missed this entirely.
- All original 8px-floor flag cases still flag — 4px on 14px text
is still 4 < 4.2 vertical, 2px is still cramped, etc.
- Snippet now indicates which axis failed and the specific threshold
for the font-size: "6px vertical padding (need ≥4.8px for 16px text)"
instead of the old "6px padding (need >=8px)".
Fixture
- tests/fixtures/antipatterns/cramped-padding.html is a new
comprehensive side-by-side fixture with 8 flag cases and 12 pass
cases spanning small pills, cards, code blocks, interactive
elements, and big text. Replaces the prior 3-case version.
Test
- tests/detect-antipatterns-browser.test.mjs asserts exactly 8
cramped-padding findings with detailed comments listing each
expected case and which axis fails.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The quality detection rules (line-length, cramped-padding, tight-leading,
tiny-text, justified-text, all-caps-body, wide-tracking, skipped-heading)
were originally added as browser-only and wired only into the overlay
loop. The CLI's jsdom path silently skipped all of them.
Two of the eight rules genuinely need real browser layout
(line-length reads rect.width for chars-per-line; cramped-padding reads
rect.width/height to filter small badges). The other six only need
computed CSS values and pure DOM walks — they can run in jsdom too.
Refactor
- Extract a pure checkQuality(opts) from checkElementQualityDOM, taking
pre-resolved lineHeightPx and letterSpacingPx so each adapter handles
its own unit resolution.
- Add resolveFontSizePx(el, win) — walks the parent chain to compute
effective font-size in pixels, handling px / rem / em / % through
inheritance. Browsers do this automatically in getComputedStyle, but
jsdom returns "0.875rem" verbatim, which broke naive parseFloat math.
- Add resolveLengthPx(value, fontSizePx) — generic CSS length → px
helper used for line-height and letter-spacing in the Node adapter.
- Extract checkPageQualityFromDoc(doc) and add a Node call site so
skipped-heading fires from the CLI too.
- Add checkElementQuality(el, style, tag, window) Node adapter and wire
it into detectHtml's element loop.
Tests
- New tests/detect-antipatterns-browser.test.mjs — Puppeteer-backed
runner that spins up a temporary static server (port 8765, mirrors
the dev server's /fixtures/* and /js/* routes) and uses detectUrl()
to load fixtures in headless Chrome. Asserts the two browser-only
rules (cramped-padding, line-length) that need real layout.
- New tests/fixtures/antipatterns/cramped-padding.html — focused
side-by-side fixture for the cramped-padding rule. Pass column
includes a faithful replica of .detection-cmd from the homepage
(the disputed "small inline pill" case the user is deciding what
to do with). Test asserts 3 findings: 2 from the obvious flag
column + 1 from the disputed pill.
- New tests/fixtures/antipatterns/quality.html — merged side-by-side
replacement for the orphaned quality-should-flag/pass.html files.
Covers all 7 typography-quality rules. The 6 jsdom-compatible rules
are asserted in the jsdom test; line-length stays in the Puppeteer
test.
- Delete the orphaned quality-should-flag.html / quality-should-pass.html.
- Wire the new browser test into bun run test (~2.6s overhead).
Coverage win: the CLI now catches tight-leading, tiny-text,
justified-text, all-caps-body, wide-tracking, and skipped-heading on
real projects, where it previously missed all six.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Removes the 26-character truncation in TYPE_LABELS that cut off long
anti-pattern names mid-word (e.g. "icon tile stacked above heading"
became "icon tile stacked above he"). The label is sized by content
via white-space: nowrap so it grows to fit, and multi-finding overlays
that exceed the outline width already fall back to the cycling UI.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
A new icon-tile-stack detection (the canonical AI feature-card with a
small rounded-square icon container above a heading), backed by a
two-column TDD fixture, plus a single-source-of-truth design that ties
the engine to the impeccable skill so they can no longer drift silently.
Detection
- New icon-tile-stack rule (slop): heading's previousElementSibling is
a 32–128px rounded-square element with a non-transparent background
or border, contains an svg/icon-i child, and sits above (not next to)
the heading. Excludes round avatars, wide thumbnails, side-by-side
layouts, tiny icons, and hero images.
- Two-column fixture convention: a single icon-tile-stack.html with a
flag column (4 cases) and pass column (6 cases), with snippet-text
matching used by the fixture test.
Single source of truth
- Each ANTIPATTERNS entry can now declare skillSection + skillGuideline.
18 of 25 rules carry these fields; the build's new
validateAntipatternRules() in scripts/build.js fails if any declared
skillGuideline isn't found verbatim in the right SKILL.md section.
- scripts/build-extension.js now includes the description field in
extension/detector/antipatterns.json (it was previously dropped).
- The existing count validator was promoted from warn to error so
command count drift fails the build the same way detection drift does.
Impeccable skill DON'Ts
- Added 4 new top-level DON'Ts that target real default AI behavior:
single-font, flat-type-hierarchy, all-caps-body, line-length.
- Cut 7 new DON'Ts I had drafted (tight-leading, tiny-text, wide-tracking,
justified-text, low-contrast, cramped-padding, skipped-heading) because
they teach things every model already knows from CSS/a11y basics. The
detector still catches all of them.
Stale count cleanup
- 22 commands → 21 across 17 references in HTML, README, NOTICE, AGENTS,
plugin.json, marketplace.json (left over from the validate skill removal).
- Dropped the hand-coded "212 design guidelines" marketing copy on the
homepage, which never mapped to any real count.
Sub-agent
- New private .claude/agents/anti-patterns.md captures the full TDD
recipe, schema, plug-in points, jsdom constraints, and pre-commit
checklist so future sessions can add rules end-to-end without
re-investigating the wiring.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Previously checkColors bailed out whenever an ancestor used a gradient
background, since resolveBackground returned null. As a result, gray or
low-contrast text inside any gradient container was completely invisible
to both rules — e.g. the gray heading on bad-contrast.html.
Add a resolveGradientStops fallback that walks parents for gradient
stops and runs contrast against the worst-case stop, plus gray-on-color
when every stop is chromatic. parseGradientColors now also accepts hex
so jsdom fixtures with raw inline gradients work too. Extended the
color-should-flag fixture and tests to cover the gradient case.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Refactors the extension for on-demand injection (no static content_scripts
entry — content script and detector are loaded only when the user actively
opens the Impeccable panel, sidebar pane, or popup). Adds a new "Auto-scan"
preference (default: scan when the Impeccable panel opens, opt-in: scan
when DevTools opens) plus configurable line length (strict/lax) and
highlight blur on/off settings. Adds an Elements panel sidebar that shows
findings for the currently selected element.
Includes substantial overlay UX work: page-pixel-perfect spotlight mask
via clip-path, refined hover/dim states, instant transitions for snappier
feel, copy buttons for findings, hover-from-panel highlighting, and a
brand-aware exception list so the font check no longer flags Roboto on
Google's own properties.
Robustness fixes for the MV3 service worker lifecycle: heartbeat keepalive
plus auto-reconnecting ports across panel/sidebar/devtools so transient
SW restarts don't break the panel UI, and immediate teardown on DevTools
close (replacing an unreliable setTimeout-based defer that didn't survive
SW termination).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Adds a Manifest V3 Chrome extension that injects the detector when
DevTools opens, with a dedicated panel for browsing findings, a toolbar
popup for quick scan/toggle, and per-rule settings synced via
chrome.storage. Categorizes anti-patterns into AI slop vs quality
issues with visual differentiation (sparkle prefix, panel grouping).
Overlay labels are polished with flush positioning, cycling for
multi-finding elements, and synchronized hover darkening.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Merges the impeccable-detect CLI repo (pbakaus/impeccable-cli@831a6cc)
into this repo. The BSL-1.1 license that motivated the split is gone;
everything is now Apache 2.0.
- Add bin/, src/, detection tests and fixtures from CLI repo
- Merge package.json: name → "impeccable", add bin/exports/files fields
- Internal refs now read from local src/ instead of node_modules/
- Update SPDX headers, NOTICE.md, CLAUDE.md, FAQ, npm README
- Add prepack/postpack scripts for CLI-focused README on npm
- Remove terminal license labels (no longer needed)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Paul BakausandClaude Opus 4.6