Configure Coverage

/configure:coverage

Check and configure code coverage thresholds and reporting for test frameworks.

When to Use This Skill

Context

• Project root: !pwd
• Package files: !find . -maxdepth 1 \( -name 'package.json' -o -name 'pyproject.toml' -o -name 'Cargo.toml' \)
• Vitest config: !find . -maxdepth 1 -name 'vitest.config.*'
• Jest config: !find . -maxdepth 1 -name 'jest.config.*'
• Coverage dir: !find . -maxdepth 1 -type d -name 'coverage'
• Codecov config: !find . -maxdepth 1 \( -name 'codecov.yml' -o -name '.codecov.yml' \)
• Project standards: !find . -maxdepth 1 -name '.project-standards.yaml'

Parameters

Parse from command arguments:

• --check-only: Report compliance status without modifications (CI/CD mode)
• --fix: Apply fixes automatically without prompting
• --threshold <percentage>: Set coverage threshold (default: 80)

Default threshold: 80% (lines, branches, functions, statements)

Supported frameworks:

• Vitest: @vitest/coverage-v8 or @vitest/coverage-istanbul
• Jest: Built-in coverage with --coverage
• pytest: pytest-cov plugin
• Rust: cargo-llvm-cov or cargo-tarpaulin

Execution

Execute this code coverage compliance check:

Step 1: Detect test framework and coverage configuration

Check for framework indicators:

Use WebSearch or WebFetch to verify latest versions of coverage tools before configuring.

Step 2: Analyze current coverage state

For the detected framework, check configuration completeness:

Vitest:

• [ ] Coverage provider configured (v8 or istanbul)
• [ ] Coverage reporters configured (text, json, html, lcov)
• [ ] Thresholds set for lines, functions, branches, statements
• [ ] Exclusions configured (node_modules, dist, tests, config files)
• [ ] Output directory specified

Jest:

• [ ] collectCoverage enabled
• [ ] coverageProvider set (v8 or babel)
• [ ] collectCoverageFrom patterns configured
• [ ] coverageThresholds configured
• [ ] coverageReporters configured

pytest:

• [ ] pytest-cov installed
• [ ] [tool.coverage.run] section exists
• [ ] [tool.coverage.report] section exists
• [ ] Coverage threshold configured (--cov-fail-under)

Rust (cargo-llvm-cov):

• [ ] cargo-llvm-cov installed
• [ ] Coverage configuration in workspace
• [ ] HTML/LCOV output configured

Step 3: Generate compliance report

Print a formatted compliance report:

Code Coverage Compliance Report
================================
Project: [name]
Framework: [Vitest 2.x | pytest 8.x | cargo-llvm-cov 0.6.x]

Coverage Configuration:
  Provider                @vitest/coverage-v8        [CONFIGURED | MISSING]
  Reporters               text, json, html, lcov     [ALL | PARTIAL]
  Output directory        coverage/                  [CONFIGURED | DEFAULT]
  Exclusions              node_modules, dist, tests  [CONFIGURED | INCOMPLETE]

Thresholds:
  Lines                   80%                        [PASS | LOW | NOT SET]
  Branches                80%                        [PASS | LOW | NOT SET]
  Functions               80%                        [PASS | LOW | NOT SET]
  Statements              80%                        [PASS | LOW | NOT SET]

CI/CD Integration:
  Coverage upload         codecov/coveralls          [CONFIGURED | MISSING]
  Artifact upload         coverage reports           [CONFIGURED | MISSING]

Overall: [X issues found]

If --check-only, stop here.

Step 4: Configure coverage (if --fix or user confirms)

Apply coverage configuration based on detected framework. Use templates from REFERENCE.md:

1. Install coverage provider (e.g., @vitest/coverage-v8, pytest-cov) 2. Update config file with thresholds, reporters, exclusions 3. Add scripts to package.json or pyproject.toml 4. Configure CI/CD with Codecov upload and artifact storage

Step 5: Update standards tracking

Update .project-standards.yaml:

standards_version: "2025.1"
last_configured: "[timestamp]"
components:
  coverage: "2025.1"
  coverage_threshold: 80
  coverage_provider: "[v8|istanbul|pytest-cov|llvm-cov]"
  coverage_reporters: ["text", "json", "html", "lcov"]
  coverage_ci: "codecov"

Step 6: Print final report

Print a summary of changes applied, scripts added, and next steps for verifying coverage.

For detailed configuration templates, see REFERENCE.md.

Agentic Optimizations

Flags

Examples

# Check compliance and offer fixes
/configure:coverage

# Check only, no modifications
/configure:coverage --check-only

# Auto-fix with custom threshold
/configure:coverage --fix --threshold 90

Error Handling

• No test framework detected: Suggest running /configure:tests first
• Coverage provider missing: Offer to install
• Invalid threshold: Reject values <0 or >100
• CI token missing: Warn about Codecov/Coveralls setup

See Also

• /configure:tests - Configure testing frameworks
• /test:coverage - Run tests with coverage
• /configure:all - Run all compliance checks
• Codecov documentation: https://docs.codecov.com
• pytest-cov documentation: https://pytest-cov.readthedocs.io

Coverage Configuration Reference

Detailed configuration templates for code coverage tools.

Vitest Coverage Configuration

Install Coverage Provider

npm install --save-dev @vitest/coverage-v8
# or for Istanbul
npm install --save-dev @vitest/coverage-istanbul

vitest.config.ts Template

import { defineConfig } from 'vitest/config';

export default defineConfig({
  test: {
    coverage: {
      provider: 'v8',

      reporter: [
        'text',           // Console output
        'json',           // JSON report for tools
        'html',           // HTML report for browsing
        'lcov',           // LCOV for CI/CD (codecov, coveralls)
      ],

      reportsDirectory: './coverage',

      thresholds: {
        lines: 80,
        functions: 80,
        branches: 80,
        statements: 80,
      },

      include: ['src/**/*.{js,ts,jsx,tsx}'],

      exclude: [
        'node_modules/',
        'dist/',
        'tests/',
        '**/*.config.*',
        '**/*.d.ts',
        '**/*.test.*',
        '**/*.spec.*',
        '**/types/',
        '**/__tests__/',
      ],

      clean: true,
      all: true,
      skipFull: false,
    },
  },
});

Package.json Scripts

{
  "scripts": {
    "test:coverage": "vitest run --coverage",
    "coverage:report": "open coverage/index.html",
    "coverage:check": "vitest run --coverage --reporter=json"
  }
}

Jest Coverage Configuration

jest.config.ts Template

import type { Config } from 'jest';

const config: Config = {
  collectCoverage: true,
  coverageProvider: 'v8',

  collectCoverageFrom: [
    'src/**/*.{js,jsx,ts,tsx}',
    '!src/**/*.d.ts',
    '!src/**/*.stories.*',
    '!src/**/__tests__/**',
    '!src/**/types/**',
  ],

  coverageDirectory: 'coverage',

  coverageReporters: [
    'text',
    'text-summary',
    'json',
    'html',
    'lcov',
  ],

  coverageThresholds: {
    global: {
      lines: 80,
      functions: 80,
      branches: 80,
      statements: 80,
    },
    './src/critical/**/*.ts': {
      lines: 90,
      functions: 90,
      branches: 90,
      statements: 90,
    },
  },

  coveragePathIgnorePatterns: [
    '/node_modules/',
    '/dist/',
    '/tests/',
    '.config.js',
  ],
};

export default config;

pytest Coverage Configuration

Install pytest-cov

uv add --group dev pytest-cov

pyproject.toml Template

[tool.pytest.ini_options]
addopts = [
    "-v",
    "--cov=src",
    "--cov-report=term-missing",
    "--cov-report=html",
    "--cov-report=xml",
    "--cov-report=json",
    "--cov-fail-under=80",
]

[tool.coverage.run]
source = ["src"]
branch = true
parallel = true
omit = [
    "*/tests/*",
    "*/migrations/*",
    "*/__init__.py",
    "*/config.py",
    "*/settings.py",
]

[tool.coverage.report]
precision = 2
show_missing = true
fail_under = 80

exclude_lines = [
    "pragma: no cover",
    "def __repr__",
    "def __str__",
    "if __name__ == .__main__.:",
    "raise AssertionError",
    "raise NotImplementedError",
    "if 0:",
    "if False:",
    "if TYPE_CHECKING:",
    "@abstractmethod",
    "@overload",
]

[tool.coverage.html]
directory = "coverage/html"

[tool.coverage.xml]
output = "coverage/coverage.xml"

[tool.coverage.json]
output = "coverage/coverage.json"

Rust Coverage Configuration

Install cargo-llvm-cov

cargo install cargo-llvm-cov --locked

.cargo/config.toml Template

[alias]
coverage = "llvm-cov --html --open"
coverage-lcov = "llvm-cov --lcov --output-path lcov.info"

Cargo.toml Coverage Metadata

[package.metadata.coverage]
exclude = [
    "tests/*",
    "benches/*",
    "examples/*",
]

Run Coverage

# Generate HTML report
cargo coverage

# Generate LCOV for CI
cargo coverage-lcov

CI/CD Integration

GitHub Actions - Vitest/Jest

- name: Run tests with coverage
  run: npm run test:coverage

- name: Upload coverage to Codecov
  uses: codecov/codecov-action@v4
  with:
    token: ${{ secrets.CODECOV_TOKEN }}
    files: ./coverage/lcov.info
    flags: unittests
    name: codecov-umbrella
    fail_ci_if_error: true

- name: Upload coverage artifacts
  uses: actions/upload-artifact@v4
  if: always()
  with:
    name: coverage-report
    path: coverage/

GitHub Actions - pytest

- name: Run tests with coverage
  run: uv run pytest --cov --cov-report=xml --cov-report=html

- name: Upload coverage to Codecov
  uses: codecov/codecov-action@v4
  with:
    token: ${{ secrets.CODECOV_TOKEN }}
    files: ./coverage/coverage.xml
    flags: unittests
    name: codecov-umbrella
    fail_ci_if_error: true

- name: Upload coverage artifacts
  uses: actions/upload-artifact@v4
  if: always()
  with:
    name: coverage-report
    path: coverage/

GitHub Actions - Rust

- name: Install cargo-llvm-cov
  uses: taiki-e/install-action@cargo-llvm-cov

- name: Generate coverage
  run: cargo llvm-cov --all-features --lcov --output-path lcov.info

- name: Upload coverage to Codecov
  uses: codecov/codecov-action@v4
  with:
    token: ${{ secrets.CODECOV_TOKEN }}
    files: ./lcov.info
    flags: unittests
    fail_ci_if_error: true

Coverage Badges

Codecov:

[![codecov](https://codecov.io/gh/USERNAME/REPO/branch/main/graph/badge.svg)](https://codecov.io/gh/USERNAME/REPO)

Coveralls:

[![Coverage Status](https://coveralls.io/repos/github/USERNAME/REPO/badge.svg?branch=main)](https://coveralls.io/github/USERNAME/REPO?branch=main)

Codecov Configuration

codecov.yml Template

coverage:
  status:
    project:
      default:
        target: 80%
        threshold: 1%
    patch:
      default:
        target: 80%

comment:
  layout: "reach,diff,flags,tree"
  behavior: default
  require_changes: false

Codecov Setup Steps

1. Sign up at https://codecov.io 2. Add repository 3. Copy token from Codecov dashboard 4. Add secret: GitHub repo -> Settings -> Secrets -> CODECOV_TOKEN 5. Add upload step to workflow