mcpbeat

Bun Test Coverage

secondsky/bun-test-coverage

Use for test coverage with Bun, --coverage flag, lcov reports, thresholds, and CI integration.

This is a copy. The original lives at comeonoliver/bun-test-coverage.

833 tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
202
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/secondsky/claude-skills --skill bun-test-coverage

The instruction itself

15 sections, as written by the author

Bun Test Coverage

Bun has built-in code coverage reporting without additional dependencies.

Enabling Coverage

# Enable coverage
bun test --coverage

# With threshold (fail if below)
bun test --coverage --coverage-threshold 80

Configuration in bunfig.toml

[test]
coverage = true
coverageThreshold = 0.8  # 80% minimum
coverageDir = "./coverage"

# Patterns to ignore
coverageSkipTestFiles = true

Coverage Output

------------------|---------|---------|-------------------
File              | % Funcs | % Lines | Uncovered Line #s
------------------|---------|---------|-------------------
All files         |   85.71 |   89.23 |
 src/index.ts     |  100.00 |  100.00 |
 src/utils.ts     |   75.00 |   82.35 | 23-25, 41-43
 src/api.ts       |   80.00 |   85.00 | 67, 89-92
------------------|---------|---------|-------------------

Coverage Reporters

# Default console output
bun test --coverage

# Generate lcov report
bun test --coverage --coverage-reporter=lcov

# Multiple reporters
bun test --coverage --coverage-reporter=text --coverage-reporter=lcov

Available Reporters

| Reporter | Output |

|----------|--------|

| text | Console table (default) |

| lcov | coverage/lcov.info for CI tools |

| json | coverage/coverage.json |

Coverage Thresholds

Set minimum coverage requirements:

# Fail if coverage < 80%
bun test --coverage --coverage-threshold 80

# Per-metric thresholds in bunfig.toml
[test]
coverage = true
coverageThreshold = {
  lines = 80,
  functions = 75,
  branches = 70
}

Excluding Files

[test]
coverage = true

# Skip test files from coverage
coverageSkipTestFiles = true

# Patterns to exclude
coverageIgnore = [
  "**/*.test.ts",
  "**/fixtures/**",
  "**/mocks/**"
]

CI Integration

GitHub Actions

- name: Run tests with coverage
  run: bun test --coverage --coverage-reporter=lcov

- name: Upload coverage to Codecov
  uses: codecov/codecov-action@v5
  with:
    files: ./coverage/lcov.info

Output Directory

# Custom output directory
bun test --coverage --coverage-dir=./reports/coverage

Programmatic Coverage

import { test, expect } from "bun:test";

// Get coverage data programmatically
const coverage = Bun.coverage;

// Access after tests complete
process.on("exit", () => {
  console.log(coverage.getCoverageData());
});

Common Errors

| Error | Cause | Fix |

|-------|-------|-----|

| Coverage threshold not met | Coverage below threshold | Increase test coverage |

| No coverage data | Files not executed | Check test includes file |

| lcov not found | Missing reporter | Add --coverage-reporter=lcov |

Best Practices

  • Set realistic thresholds - Start at 60%, increase gradually
  • Exclude generated files - Mock files, type definitions
  • Focus on critical paths - Business logic over boilerplate
  • Run in CI - Prevent coverage regression

When to Load References

Load references/reporters.md when:

  • Custom reporter configuration
  • CI/CD integration details
  • Codecov/Coveralls setup

How to use it

Copy the folder

Take secondsky/bun-test-coverage from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.