[DevOps & Infra] Browser automation, debugging, and performance analysis using Puppeteer CLI scripts...
Goal: Run comprehensive UI tests on a website and generate a detailed visual report.
For individual page/component testing with Playwright scripts, use
webapp-testinginstead.
Workflow:
overflow: auto) instead of reflowing is acceptable, NOT a failure; a block that clips content or hides a control off-screen with no scroll path is a failure.Key Rules:
Be skeptical. Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence percentages (Idea should be more than 80%).
Pre-read (design system): Load designSystem.canonicalDoc + tokenFiles from docs/project-config.json so visual/style assertions reference real token names (--brand-*, $brand-*) instead of guesses.
Activate the browser automation tooling.
Run comprehensive UI tests on a website and generate a detailed report.
For testing protected routes that require authentication, follow this workflow:
Instruct the user to:
Ask the user to provide one of:
Use the available browser automation runner to inject credentials before testing:
# Cookies
# Add cookies before navigating to protected pages.
# Bearer token
# Set the Authorization header or localStorage token key before navigation.
# Local/session storage
# Populate the required storage keys, then reload the page.
After auth injection, the browser session persists. Run tests normally with the available browser automation runner:
# Navigate and screenshot protected pages.
# Save outputs in the report directory for later analysis.
--cookies '<json>' - Inject cookies (JSON array)--token '<token>' - Inject Bearer token--token-key '<key>' - localStorage key for token (default: access_token)--header '<name>' - Set HTTP header with token (e.g., Authorization)--local-storage '<json>' - Inject localStorage items--session-storage '<json>' - Inject sessionStorage items--reload true - Reload page after injection--clear true - Clear saved auth sessionplan skill to organize the test plan & report in the current project directory.tester subagents or tool calls in parallel to test all pages, forms, navigation, user flows, accessibility, functionalities, usability, responsive layouts, cross-browser compatibility, performance, security, seo, etc.visual analysis tooling to analyze all screenshots and visual elements.AskUserQuestion tool to ask if user wants to preview the report with /preview slash command.The 40 clauses of SYNC:ui-ux-design-principles (full body inlined below in this skill) apply here in the REVIEW role, restricted to what a LIVE BROWSER SESSION can observe. Run them as NINE focused passes โ one dimension at a time against the running site, never one simultaneous sweep across all nine. Answer each Think: prompt from first principles, then drive the browser to prove or disprove it.
Out of scope for this skill โ say so plainly in the report, never guess. Clauses judgeable only by reading SOURCE or the DESIGN-TOKEN system belong to /ui-review and are routed there, not answered from a screenshot: UI-1.2 (signal order), UI-2.1 (family/weight inventory), UI-2.5 (fixed 6-step type scale), UI-3.2 (one accent, one job), UI-4.1-UI-4.3 (base spacing unit, gap-vs-margin ownership, inner-vs-outer padding), UI-6.3 (user's vocabulary vs internal naming), UI-7.1 (does each field still need to exist).
Evidence per finding: UI-<clause> + the runtime locator (URL/route ยท viewport size ยท screenshot path) + the MEASURED value wherever the clause names one (computed contrast ratio, hit-box px, layout shift, response ms, characters per line, animation ms), plus file:line whenever the audit can identify the owning source. A clause carrying a number is satisfied only by a measured number โ NEVER by "looks fine".
Severity: this skill defines no tier vocabulary and this pass introduces none โ record findings in the existing report structure (key findings + recommendations), ordered by user impact. When this audit feeds /ui-review, that skill's BLOCKED / WARN / PASS rubric governs the merge decision.
| # | Dimension (runtime-observable clauses) | Think: |
|---|---|---|
| 1 | Visual hierarchy & state coverage โ UI-1.1, UI-1.3-UI-1.5 |
On first paint, which element does the eye land on, and is it the one the page exists for? Are groups separated by whitespace or by borders? Drive each surface to EMPTY, LOADING and ERROR โ what renders? |
| 2 | Typography as rendered โ UI-2.2-UI-2.4 |
Measure the computed body size (16px web, 17px mobile, never below 14px), the characters per line at each tested width (45-75), and the line-height ratio (1.5 body, 1.1-1.2 display). |
| 3 | Colour & contrast as rendered โ UI-3.1, UI-3.3, UI-3.4 |
Compute the ratio for every rendered text and UI-edge pair (4.5:1 / 3:1) โ measured, never judged from the screenshot by eye. Is any status conveyed by colour alone? Toggle dark mode: lifted surfaces or an inversion? |
| 4 | Responsive breakpoints โ UI-4.4 |
At each tested width, where does the layout stop working, and does the breakpoint sit there or at a device name? (The ~320px minimum bar in the test plan still decides pass/fail; UI-4.4 adds WHERE the break belongs.) |
| 5 | Interaction & feedback โ UI-5.1-UI-5.5 |
Press each control: what changes within 100ms? Walk all 5 states (default/hover/focus/active/disabled) โ which is unstyled? Tab through: is the focus ring visible? Time the transitions (150-250ms, ease-out) and re-run with reduced-motion enabled. Is a confirmation used where undo would do? |
| 6 | Navigation & IA โ UI-6.1, UI-6.2, UI-6.4 |
Landing cold on each route: where am I, what's here, where next? Count the top-level destinations (max 5). Deep-link the state and press back โ does it land somewhere sensible? |
| 7 | Forms & input โ UI-7.2-UI-7.5 |
Fill each field: does the label stay visible? Does validation fire on blur with a message saying how to fix it? Does the mobile keyboard/autocomplete match the data type? Trigger an error, navigate away, refresh โ does the typed data survive? |
| 8 | Mobile & touch โ UI-8.1-UI-8.4 |
At a touch viewport, measure each target's hit box (not the icon) and neighbour spacing (>=44x44pt, 8px apart). Where do primary actions sit relative to the thumb? Is anything gesture-only? Open the keyboard and check safe areas. (No touch viewport in the matrix โ skip with the reason stated.) |
| 9 | Speed & perceived speed โ UI-9.1-UI-9.4 |
Throttle the connection: is structure shown before data (skeleton vs spinner), does anything shift as it lands, and is an optimistic update rolled back VISIBLY on failure? Go offline and force a timeout โ designed state or hang? |
Precedence: the project design-system docs pre-read above (designSystem.canonicalDoc + tokenFiles) OUTRANK these clauses; a genuine conflict is reported with BOTH sides and taken to the user โ NEVER resolved silently. Skip a dimension only when the site exposes no surface it can apply to, and state the skip with its reason.
How to write reports:
IMPORTANT: Stop at testing and reporting โ do not start implementing the fixes. IMPORTANT: Analyze the skills catalog and activate the skills that are needed for the task during the process.
[IMPORTANT] Use
TaskCreateto break ALL work into small tasks BEFORE starting โ including tasks for each file read. This prevents context loss from long files. For simple tasks, AI MUST ATTENTION ask user whether to skip.
docs/project-reference/domain-entities-reference.md โ Domain entity catalog, relationships, cross-service sync (read when task involves business entities/models)Critical Thinking Mindset โ Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence >80% to act. Anti-hallucination: Never present guess as fact โ cite sources for every claim, admit uncertainty freely, self-check output for errors, cross-reference independently, stay skeptical of own confidence โ certainty without evidence root of all hallucination.
Evidence-Based Reasoning โ Speculation is FORBIDDEN. Every claim needs proof.
- Cite
file:line, grep results, or framework docs for EVERY claim- Declare confidence: >80% act freely, 60-80% verify first, <60% DO NOT recommend
- Cross-service validation required for architectural changes
- "I don't have enough evidence" is valid and expected output
BLOCKED until:
- [ ]Evidence file path (file:line)- [ ]Grep search performed- [ ]3+ similar patterns found- [ ]Confidence level statedForbidden without proof: "obviously", "I think", "should be", "probably", "this is because" If incomplete โ output:
"Insufficient evidence. Verified: [...]. Not verified: [...]."
Test-Failure Fault Adjudication โ When a test fails (or you are debugging or fixing a failure), the job is to determine who is at fault โ the source code or the test code. Getting that verdict right matters more than turning the suite green. Binds every debug / fix / test skill identically.
- Provisional verdict before touching either side. Classify the observed evidence as SOURCE-WRONG, TEST-WRONG, TEST-NOT-OPTIMAL, ENVIRONMENT-BLOCKED, or AMBIGUOUS; then
/debug-investigateand trace end-to-start before editing. A green-again suite is NOT the goal.- Triangulate against the spec AND the source. If a governing Feature Spec covers the behavior (e.g.
docs/specs/**โ ยง3 ACs / ยง4 BRs / ยง5 invariants / ยง8 TCs), it is the tiebreaker for intended behavior โ compare BOTH the production source and the failing test against it. With no spec, the documented intent / acceptance criteria / caller contract is the reference. Decide from this evidence whether the SOURCE is wrong or the TEST is wrong.- Classify who is at fault, then fix the wrong side at its root:
- SOURCE-WRONG โ production code violates the spec's intended behavior or a clear invariant โ fix the source at the owning layer; keep or strengthen the test that caught it.
- TEST-WRONG โ the test encodes a stale or incorrect assertion, setup, or expectation that contradicts intended behavior โ fix the test at its root. NEVER weaken an assertion, add a skip, or relax a timeout to force green.
- TEST-NOT-OPTIMAL โ intended behavior is valid but the test seam, timing, or assertion signal is fragile โ improve the test without weakening the invariant.
- ENVIRONMENT-BLOCKED โ infrastructure or external state prevents a source/test verdict โ preserve diagnostics and stop mutation until the environment is healthy.
- AMBIGUOUS โ evidence or intended behavior does not safely select an owner โ ask the user or canonical owner before editing.
- NEVER change a test to match broken source, and NEVER change source to satisfy a broken test. (Migration code excluded โ schema/data migrations are one-time execution paths, not core application logic.)
- Ask the user when intended behavior is unclear. If no spec covers the behavior, the spec is silent, or the spec is ambiguous about which side is correct, STOP and
AskUserQuestion(or consult the canonical spec owner) before editing either side โ never silently pick source or test just to make the suite pass.Reconcile to intended behavior, never to whichever side currently passes โ green can encode the very bug.
AI Mistake Prevention โ Failure modes to avoid on every task:
Re-read files after context changes. Context compaction, resume, or long-running work can make memory stale; verify current files before acting. Verify generated content against source evidence. AI hallucinates APIs, names, claims, and document facts. Check the relevant source before documenting or referencing. Check downstream references before deleting or renaming. Removing an artifact can stale docs, generated mirrors, configs, and callers; map references first. Trace the full impact chain after edits. Changing a definition can miss derived outputs and consumers. Follow the affected chain before declaring done. Verify ALL affected outputs, not just the first. One green check is not all green checks; validate every output surface the change can affect. Assume existing values are intentional โ ask WHY before changing OR flagging one as a defect. Before changing or reporting a constant, limit, flag, cutoff, wording, or pattern, read nearby context and history, the CALLER's ordering, and 2+ sibling call sites of the same convention. A doc stating WHAT without WHY is missing rationale, not proof of a missing guard. Surface ambiguity before acting โ don't pick silently. Multiple valid interpretations require an explicit question or stated assumption with risk. Assert the outcome your system owns, not the intermediate state your infrastructure owns. When verifying async work, assert the final business state โ never the delivery/retry bookkeeping held in shared infrastructure that any co-running process can write. Such a check passes when run alone and flakes the moment anything else shares that infrastructure. Keep shared guidance role-relevant. Universal guidance must help every receiving skill or agent; code-specific obligations belong only in code-specific protocols.
UI/UX Design Principles (Rev 1.0 โ 40 clauses, web + mobile) โ the working rule set for ANY task that designs, plans, implements, or reviews a user interface. Applies to BOTH platforms unless a clause names one (ยง8 is mobile/touch). Cite clauses by ID:
UI-3.1,UI-8.2.Precedence: project design-system / SCSS / frontend-pattern docs OUTRANK these clauses; these clauses outrank generic taste. A genuine conflict is SURFACED to the user with both sides โ NEVER resolved silently. โ why: the project's own recorded decision is the authority; these clauses are the default when it is silent.
1.0 Visual Hierarchy & Layout
UI-1.1One focal point per screen. Two elements competing for first read โ demote one.UI-1.2Signal order: size โ weight โ colour โ position. Use the cheapest signal that works before adding another.UI-1.3Group by proximity, NEVER by border. Whitespace separates cleanly; boxes inside boxes do not.UI-1.4Align to a shared edge. Every unexplained indent reads as an accident.UI-1.5Design the empty, loading and error state FIRST. The full state is the easy one.2.0 Typography
UI-2.1Max 2 families, 3 weights each. More variety reads as inconsistency, not range.UI-2.2Body text 16px web, 17px mobile. NEVER below 14px for anything a user must read.UI-2.3Line length 45โ75 characters. Constrain the measure, not the container.UI-2.4Leading scales inversely with size: 1.5 body, 1.1โ1.2 display.UI-2.5Fixed type scale โ 6 named steps shared with engineering. NEVER one-off sizes.3.0 Colour & Contrast
UI-3.1Contrast 4.5:1 text, 3:1 UI edges. Measure it โ NEVER judge by eye on a bright screen.UI-3.2One accent, one job. An accent that is everywhere points at nothing.UI-3.3Colour NEVER carries meaning alone โ pair it with an icon, label or position.UI-3.4Dark mode is NOT inverted light mode. Lift surfaces to signal elevation; soften pure-white text.4.0 Spacing & Grid
UI-4.1One spacing unit, multiplied โ 4px or 8px base; every gap a multiple of it.UI-4.2Space belongs to the container, not the child. Usegap; reserve margins for exceptions.UI-4.3Tighter inside, looser between โ inner padding always smaller than the gap to the next group.UI-4.4Breakpoints follow content, not devices. Break where the layout stops working.5.0 Interaction & Feedback
UI-5.1Every action gets a response under 100ms, even when the result takes longer.UI-5.2Specify all 5 states โ default, hover, focus, active, disabled โ plus loading where it applies.UI-5.3Prefer undo over confirmation. Confirm ONLY what cannot be reversed.UI-5.4Motion clarifies cause and effect: 150โ250ms, ease-out, honours reduced-motion.UI-5.5Keep the visible focus ring. Restyle it if it clashes; NEVER remove it.6.0 Navigation & IA
UI-6.1Every screen answers: where am I, what's here, where next.UI-6.2Max 5 top-level destinations. Depth beats a crowded first level.UI-6.3Label by the user's word, not the internal one. Team vocabulary is not a taxonomy.UI-6.4Every state deserves a URL or a back path. Deep links and hardware back must land somewhere sensible.7.0 Forms & Input
UI-7.1Ask for less. Every field needs a reason it exists today.UI-7.2Labels stay visible. Placeholders are hints, NEVER labels.UI-7.3Validate on blur, not on keystroke. Errors sit next to the field and say how to fix it.UI-7.4Match keyboard to data type โ correct input type, autocomplete and autocapitalise on every field.UI-7.5NEVER lose entered data. Preserve input across errors, navigation and refresh.8.0 Mobile & Touch (mobile/touch surfaces)
UI-8.1Hit target โฅ44ร44pt, 8px apart. The target may exceed the visible icon.UI-8.2Primary actions in the bottom third โ that is where the thumb lives.UI-8.3Gestures are shortcuts, NEVER the only route. Anything swipeable is also tappable.UI-8.4Respect safe areas and the keyboard. Notch, home indicator and on-screen keyboard all steal space.9.0 Speed & Perceived Speed
UI-9.1Show structure before data โ skeletons for known layouts, spinners only for unknown waits.UI-9.2Assume success optimistically. Update UI first, reconcile after, roll back visibly on failure.UI-9.3Reserve space for anything that loads. Images, ads and fonts must NEVER shift the layout.UI-9.4Design for the slow connection. Offline, timeout and retry are states, NOT edge cases.Apply by role โ the clauses are one set; what you DO with them depends on the task:
Role Obligation DESIGN / PLAN a surface Clauses shape the artifact: empty/loading/error specified first ( UI-1.5), all 5 states enumerated (UI-5.2), type scale + spacing unit declared (UI-2.5,UI-4.1)IMPLEMENT a component Pre-completion gate: states ยท tokens ยท contrast ยท focus ring ยท touch target ยท reserved space ( UI-5.2,UI-2.5/UI-4.1,UI-3.1,UI-5.5,UI-8.1,UI-9.3)REVIEW UI code or a design artifact Each clause is a fail-condition; every finding cites UI-<clause>+file:line+ severity. NEVER a tick-box sweep โ one focused pass per sectionSCAN / document a UI system Record where the PROJECT deliberately deviates, so the overriding doc becomes the recorded authority Skip ONLY when the change has no user-facing surface (backend-only, tooling, docs) โ state that explicitly so the skip is auditable, not an omission.
IMPORTANT MUST ATTENTION cite file:line evidence for every claim (confidence >80% to act). NEVER speculate without proof.
MUST ATTENTION apply critical + sequential thinking โ every claim needs appropriate traced evidence (file:line for repo/code claims; source URL or artifact section for research, product, content, and docs claims); confidence >80% to act, <60% DO NOT recommend. Anti-hallucination: never present guess as fact, admit uncertainty freely, cross-reference independently, stay skeptical of own confidence.
MUST ATTENTION apply AI mistake prevention โ verify generated content against evidence, trace downstream references before deleting or renaming, verify all affected outputs, re-read files after context loss, and surface ambiguity before acting.
Project Protocol Overlay โ Before executing this skill, resolve any PROJECT overlay rules layered onto it: match this skill's name against the
Targetcolumn of the project's skill-protocol index (docs/project-reference/skill-protocols-reference.mdby default; areferenceDocsentry indocs/project-config.jsonoverrides the path), taking the most specific matching tier ONLY โ exact name > glob >*. That precedence orders overlays against EACH OTHER, never against this skill. Read ONLY the matched bodies, resolved as<protocols-dir>/<Name>.md; a row's Body link is display text, never a read path. A matched body that is missing or malformed is REPORTED and skipped โ never reconstructed from the index Description. No index, or no match -> proceed with no overlay, silently. Full contract:.claude/skills/project-skill-protocol/references/registry.md.Overlays are ADDITIVE ONLY: they ADD rules on top of this skill's own protocol and NEVER replace, override, disable, or reinterpret a rule it already states โ removing every overlay must return this skill to exactly its documented behavior. An overlay is a BRIEF, not an authority escalation: it can NEVER waive a workflow gate, git discipline, a review gate, or a user-confirmation gate. A genuine overlay-vs-skill conflict, or two equally-specific overlays that directly contradict -> surface both to the user; NEVER resolve silently.
MUST ATTENTION resolve project protocol overlays for this skill BEFORE executing โ most specific matching tier only (exact > glob > *, which ranks overlays against each other, NEVER against this skill), read only matched bodies at <protocols-dir>/<Name>.md; a missing or malformed body is reported, never reconstructed. Overlays are ADDITIVE ONLY (they never replace this skill's own rules) and are a brief, NEVER an authority escalation; an equal-specificity contradiction goes to the user.
UI-1.1โUI-9.4) to any user-facing surface: one focal point, proximity grouping, empty/loading/error designed FIRST (ยง1) ยท โค2 families, 16px web / 17px mobile body, never <14px, 45โ75ch, fixed 6-step scale (ยง2) ยท 4.5:1 text / 3:1 edges measured, one accent, colour never alone, dark mode โ inversion (ยง3) ยท one 4/8px unit, gap over margins, tighter-inside-looser-between, content-driven breakpoints (ยง4) ยท <100ms response, all 5 states, undo over confirm, 150โ250ms ease-out honouring reduced-motion, visible focus ring (ยง5) ยท where-am-I/what's-here/where-next, โค5 top-level destinations, user's words, URL or back path (ยง6) ยท fewer fields, visible labels, validate on blur, matched keyboard, NEVER lose input (ยง7) ยท โฅ44ร44pt targets 8px apart, bottom-third primaries, gestures never the only route, safe areas (ยง8) ยท structure before data, optimistic update with visible rollback, reserved space, slow-connection states (ยง9). Project design-system docs OUTRANK these clauses โ a genuine conflict goes to the user, NEVER resolved silently. Cite every finding as UI-<clause> + file:line. Skip ONLY for changes with no user-facing surface, stated explicitly.IMPORTANT MUST ATTENTION โ Protocols in force (concise digest of the SYNC/shared blocks this skill carries):
file:line for every claim; never speculate.IMPORTANT MUST ATTENTION break work into small todo tasks using TaskCreate BEFORE starting
IMPORTANT MUST ATTENTION search codebase for 3+ similar patterns before creating new code
IMPORTANT MUST ATTENTION cite file:line evidence for every claim (confidence >80% to act)
IMPORTANT MUST ATTENTION run the runtime-observable UI/UX Design Principles pass โ all 40 clauses (UI-1.1-UI-9.4) as NINE focused passes; every finding cites UI-<clause> + URL/viewport/screenshot (+ file:line when the source is identifiable) and the MEASURED number for any clause naming one; clauses needing source or design-token inspection are OUT of scope here and route to /ui-review
IMPORTANT MUST ATTENTION add a final review todo task to verify work quality
MANDATORY IMPORTANT MUST ATTENTION READ the following files before starting:
IMPORTANT MUST ATTENTION READ CLAUDE.md before starting
[TASK-PLANNING] Before acting, analyze task scope and systematically break it into small todo tasks and sub-tasks using TaskCreate.