CtrlK
BlogDocsLog inGet started
Tessl Logo

testland/browser-extension-tests

Test Chromium browser extensions (MV3) with Playwright via `launchPersistentContext` + `--load-extension` / `--disable-extensions-except` flags. Cover service worker, popup pages, content scripts, message passing, and `chrome.runtime` API mocking. Service worker auto-suspends ~30s; Playwright keeps the Worker object alive across restarts. Use when a repo builds a Chromium extension (a `manifest.json` with `manifest_version: 3` and a built `dist/`) and its popup, content-script injection, background worker, or `chrome.storage` behavior needs automated coverage.

74

Quality

93%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

SecuritybySnyk

Passed

No findings from the security scan

Overview
Quality
Evals
Security
Files

Quality

Content

85%

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

Executable, well-structured content with clean progressive disclosure and clear workflow sequencing. The only notable weakness is redundancy between the Worked example and the preceding step sections, which lightly hurts token efficiency.

Suggestions

Trim or collapse the 'Worked example' section, since it largely restates Steps 1-7; keep only the scenario narrative that adds information not already in the steps.

Consider moving the per-Step inline commentary that duplicates the How-to-use bullets into the steps alone to avoid repeating the same guidance twice.

DimensionReasoningScore

Conciseness

Mostly lean and action-oriented, but the 'Worked example' section substantially reiterates Steps 1-7 already covered in How to use / per-Step sections, so not every token earns its place. Not a 3 because of that redundancy; not a 1 because there is no concept-padding and code is dense.

2 / 3

Actionability

Fully executable TypeScript fixtures and tests with concrete selectors, assertions, and copy-paste-ready code; the referenced recipes are likewise complete and runnable.

3 / 3

Workflow Clarity

A clear numbered How-to-use sequence plus per-Step sections, with the serviceWorker wait acting as an explicit race-handling checkpoint and the Anti-patterns table supplying error-recovery feedback. Operations are non-destructive, so no destructive-validation cap applies.

3 / 3

Progressive Disclosure

SKILL.md is a well-sectioned overview that offloads advanced recipes to references/advanced-recipes.md — a real, one-level-deep file clearly signaled via a markdown link in Steps 4-6.

3 / 3

Total

11

/

12

Passed

Description

100%

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 highly specific, well-triggered description that clearly conveys both capability and use conditions, with strong natural trigger terms and a distinct niche. No significant weaknesses.

DimensionReasoningScore

Specificity

Lists multiple concrete actions — service worker, popup pages, content scripts, message passing, and chrome.runtime API mocking — via specific Playwright mechanisms (launchPersistentContext + --load-extension/--disable-extensions-except), matching the 'multiple specific concrete actions' anchor.

3 / 3

Completeness

Explicitly answers both what (test MV3 extension surfaces with Playwright) and when ('Use when a repo builds a Chromium extension ... and its popup, content-script injection, background worker, or chrome.storage behavior needs automated coverage').

3 / 3

Trigger Term Quality

Natural terms a user would say are well covered — 'Chromium extension', 'manifest.json / manifest_version: 3', 'popup', 'content-script injection', 'background worker', 'chrome.storage', 'automated coverage' — matching good coverage of natural terms.

3 / 3

Distinctiveness Conflict Risk

A clear, narrow niche (MV3 Chromium extension testing via Playwright persistent context + side-load flags) with distinct triggers unlikely to fire for unrelated skills.

3 / 3

Total

12

/

12

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

Table of Contents