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

Pending

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 has strong trigger terms and a clearly distinctive niche (Jest-to-Bun migration), making it easy to select in the right context. However, it lacks explicit 'what' actions — it reads more like a 'when to use' clause without clearly stating what concrete tasks the skill performs (e.g., rewriting test files, converting mock syntax, updating configuration).

Suggestions

Add explicit capability statements before the 'Use when' clause, e.g., 'Converts Jest test files to Bun test runner syntax, rewrites mock implementations, and migrates jest.config settings.'

Expand the 'what' portion with specific concrete actions like 'rewrites describe/it blocks, converts jest.fn() to mock(), updates package.json test scripts.'

Dimension	Reasoning	Score
Specificity	Names the domain (Jest to Bun migration) and mentions some areas like 'import compatibility, mocks, and config,' but doesn't list specific concrete actions (e.g., 'converts Jest mock syntax to Bun equivalents, rewrites jest.config to bunfig.toml').	2 / 3
Completeness	The description starts with 'Use when' which addresses the 'when' aspect, but the 'what does this do' part is weak — it lists topic areas (mocks, config) rather than clearly stating what actions the skill performs.	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 migration.	3 / 3
Distinctiveness Conflict Risk	Very specific niche: migrating from Jest to Bun's test runner. This is unlikely to conflict with other skills given the narrow and well-defined scope combining two specific technologies and a migration context.	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, highly actionable migration guide with excellent before/after code examples covering the key Jest-to-Bun differences. Its main weaknesses are some redundancy between sections (Quick Migration vs Step-by-Step), a monolithic structure that could benefit from splitting detailed examples into reference files, and a lack of explicit validation checkpoints in the migration workflow.

Suggestions

Add explicit validation checkpoints to the Step-by-Step Migration workflow, e.g., 'Run bun test after each change category (imports, mocks, timers) to isolate failures' with a fix-and-retry loop.

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

Move detailed mock migration examples, timer migration, and custom matchers into a separate reference file (e.g., migration-patterns.md) and link from the main skill.

Dimension	Reasoning	Score
Conciseness	The skill is mostly efficient with good code examples, but there's some redundancy—the Timer Migration section contradicts the 'Requires Changes' table (showing Jest-compatible API works after all), and the Step-by-Step Migration section largely repeats the Quick Migration section. The 'Fully Compatible' table states obvious things like 'Identical' repeatedly.	2 / 3
Actionability	Excellent actionability with fully executable, copy-paste ready code examples for every migration scenario. Before/after patterns are concrete and specific, covering mocks, timers, snapshots, configuration, and common error resolutions.	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 the first 50 lines.	2 / 3
Progressive Disclosure	The content is well-structured with clear headers and tables, but it's quite long for a SKILL.md—the detailed mock migration examples, timer migration, and common issues could be split into separate reference files. The 'When to Load References' section at the end hints at external files but the main content is monolithic.	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: 88da5ff

Reviewed: 17 days ago

Table of Contents

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