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testland/chart-render-tests

Chart-render regression testing across the three chart-library families - Canvas (Chart.js: locator screenshot snapshot + `canvas.toDataURL()` diff with animations disabled), SVG (D3: `outerHTML` structural snapshot with generated-ID normalization + per-element data-binding tests), and declarative specs (Vega / Vega-Lite: JSON Schema validation + Vega-Lite → Vega compile test). Detects the family from package.json imports (chart.js / d3 / vega-lite), then applies the matching recipe; full per-library depth with citations in references/chartjs.md, references/d3.md, references/vega.md. Use when a dashboard or data product renders charts and their output needs regression coverage - before a chart-library major upgrade, after a theming change, or when runtime-generated Vega specs must be proven valid before render.

74

Quality

93%

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Overview
Quality
Evals
Security
Files

Quality

Content

92%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

An excellent, executable skill body: complete code per chart family, explicit validation gates, and well-structured progressive disclosure to verified reference files. The only improvement is trimming the light narrative/doc-pointer lead-ins for maximal token efficiency.

Suggestions

Tighten the opening 'Overview' paragraph and remove 'Per the [docs]' lead-ins before each family section to push conciseness toward 5.

The canvas/D3/Vega sections each restate the library's rendering model ('Chart.js renders to <canvas>') — consider folding these into the family table once rather than repeating per section.

DimensionReasoningScore

Conciseness

Largely lean with no concept padding and compact tables/code, but the opening narrative paragraph ('Chart regressions hide behind green unit tests...') and the recurring 'Per the [docs]' lead-ins are minor trimmable throat-clearing that keep it just shy of fully efficient.

4 / 5

Actionability

Provides copy-paste-ready, executable guidance throughout — real jq/grep detection commands, a complete Playwright canvas-snapshot test, a normalizeSvg() + structural-snapshot test, and a full Ajv + Vega-Lite compile test — covering the common cases per family.

5 / 5

Workflow Clarity

Clear sequence (detect family → apply matching recipe → per-family gates) with explicit validation checkpoints (disable animation + pin DPR + waitForFunction; the three labeled Vega gates) and an Anti-patterns table serving as an error-recovery checklist.

5 / 5

Progressive Disclosure

SKILL.md is a true overview with one-level-deep, consistently signaled references (all six referenced files verified present), keeping detail in references and the body navigable.

5 / 5

Total

19

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20

Passed

Description

92%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A high-quality description: specific, third-person, with an explicit 'Use when' trigger clause and concrete per-family actions. The only soft spot is trigger-term breadth — it covers the core situational triggers but could add synonyms like 'graphs' or extensions.

DimensionReasoningScore

Specificity

Enumerates concrete actions per family — canvas toDataURL() snapshot/diff with animations disabled, SVG outerHTML structural snapshot with ID normalization + data-binding tests, Vega-Lite JSON Schema validation + compile test, plus package.json family detection — giving comprehensive coverage of the domain.

5 / 5

Completeness

Clearly states what it does (per-family regression recipes + family detection) and an explicit 'Use when...' clause with concrete triggers (library upgrade, theming change, runtime Vega specs needing validity), satisfying both halves with concrete trigger phrases.

5 / 5

Trigger Term Quality

Strong natural trigger phrasing ('dashboard or data product renders charts', 'before a chart-library major upgrade', 'after a theming change') plus library names, but omits common synonyms like 'graphs' and file extensions, leaving a few natural terms missing.

4 / 5

Distinctiveness Conflict Risk

Occupies a sharp niche — chart-render regression testing across three named families — distinct from general UI-snapshot skills, with specific triggers that minimize conflict risk.

5 / 5

Total

19

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

metadata_version

'metadata.version' is missing

Warning

Total

15

/

16

Passed

Reviewed

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