bun-jest-migration

Use when migrating from Jest to Bun's test runner, import compatibility, mocks, and config.

Quality

68%

Does it follow best practices?

Impact

—

No eval scenarios have been run

Securityby

Passed

No known issues

Optimize this skill with Tessl

npx tessl skill review --optimize ./plugins/bun/skills/bun-jest-migration/SKILL.md

Quality

Discovery

72%

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

The description targets a clear and distinctive niche (Jest-to-Bun migration) with good trigger terms, but lacks specificity in describing concrete actions the skill performs. The 'what it does' portion reads more like a topic list than a capability description, and while the 'Use when' clause is present, it essentially restates the topic rather than providing additional trigger guidance.

Suggestions

Add concrete actions describing what the skill does, e.g., 'Converts Jest test syntax to Bun test runner equivalents, rewrites mock implementations, and migrates jest.config to bunfig.toml.'

Expand the 'Use when' clause with additional trigger scenarios, e.g., 'Use when converting jest.mock to Bun mocks, replacing Jest matchers, or switching from jest.config.js to Bun configuration.'

Dimension	Reasoning	Score
Specificity	Names the domain (Jest to Bun migration) and mentions some areas like 'import compatibility, mocks, and config,' but these are more like topic areas than concrete actions. It doesn't list specific actions like 'convert Jest mock syntax to Bun equivalents' or 'rewrite jest.config to bunfig.toml'.	2 / 3
Completeness	Has a 'Use when' clause which addresses the 'when' question, but the 'what does this do' part is weak — it lists topic areas (import compatibility, mocks, config) rather than clearly describing what actions the skill performs. The 'what' is only implied through the topic listing.	2 / 3
Trigger Term Quality	Includes strong natural trigger terms: 'Jest', 'Bun', 'test runner', 'migrating', 'mocks', 'config', 'import compatibility'. These are terms a user would naturally use when seeking help with this specific migration task.	3 / 3
Distinctiveness Conflict Risk	Very specific niche: migrating from Jest to Bun's test runner. This is unlikely to conflict with general testing skills, general Bun skills, or general Jest skills due to the explicit migration framing and the specific tool pairing.	3 / 3
	Total	10 / 12 Passed

Implementation

64%

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

This is a solid migration guide with excellent actionability — the before/after code patterns are concrete, executable, and cover the most common migration scenarios. The main weaknesses are some redundancy between sections (Quick Migration vs Step-by-Step), a slightly contradictory timer section, and a migration workflow that lacks explicit validation checkpoints and error recovery loops. The content is somewhat long for a SKILL.md and could benefit from splitting detailed sections into referenced files.

Suggestions

Add explicit validation checkpoints to the Step-by-Step Migration workflow, e.g., 'Run bun test after each file conversion to catch issues incrementally' with a fix-and-retry loop.

Consolidate the 'Quick Migration' and 'Step-by-Step Migration' sections into a single workflow to eliminate redundancy.

Clarify the timer section — it first lists timers under 'Requires Changes' but then shows Jest-compatible timer APIs working identically in Bun. State clearly which timer APIs are now supported vs which require changes.

Dimension	Reasoning	Score
Conciseness	The content is mostly efficient with good before/after comparisons, but there's some redundancy — the 'Step-by-Step Migration' section largely repeats the 'Quick Migration' section, and the timer section contains slightly contradictory information (first saying timers require changes, then showing Jest-compatible APIs work). Some tables restate what the code examples already demonstrate.	2 / 3
Actionability	Excellent actionability throughout — every migration scenario includes concrete, executable before/after code examples with specific imports, commands, and configuration. The common errors table with specific error messages and fixes is particularly useful and copy-paste ready.	3 / 3
Workflow Clarity	The Step-by-Step Migration section provides a clear sequence, but lacks explicit validation checkpoints between steps. Step 5 ('Run and fix') is vague — there's no feedback loop for iterating on failures, and no guidance on what to do if specific categories of errors appear beyond checking 'first errors'.	2 / 3
Progressive Disclosure	The content references 'references/compatibility-matrix.md' at the end with clear trigger conditions, which is good progressive disclosure. However, the bundle has no files, so this reference is unverifiable. The main content itself is quite long (~200 lines) and could benefit from splitting the detailed mock/timer/snapshot sections into separate reference files.	2 / 3
	Total	9 / 12 Passed

Validation

100%

Warnings & errors only

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

Validation — 11 / 11 Passed

Validation for skill structure

No warnings or errors.

Repository: secondsky/claude-skills
Commit: 5e92b71

Reviewed: 18 days ago

Table of Contents

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