@rajzik/danger-configuration

A comprehensive DangerJS configuration package providing utilities for automated code review checks in pull requests.

Installation

npm install --save-dev @rajzik/danger-configuration danger
pnpm install --save-dev @rajzik/danger-configuration danger
yarn add --dev @rajzik/danger-configuration danger

Usage

Create a dangerfile.js in your repository root:

import {
  checkForADR,
  checkForAnyTests,
  checkForConventionalPrefix,
  checkForConventionalSquashCommit,
  checkForInvalidLocks,
  checkSourceFilesHaveTests,
  disableComponentSnapshots,
  disableNewJavaScript,
} from '@rajzik/danger-configuration';

// Check for conventional commit prefix in PR title
checkForConventionalPrefix();

// Check for squash commit format
checkForConventionalSquashCommit();

// Validate lock file changes
checkForInvalidLocks();

// Check for ADR documentation on large PRs
checkForADR('docs/adr', {
  changeThreshold: 200,
  docsUrl: 'https://example.com/docs/adr',
  fail: true,
});

// Check for test files
checkForAnyTests({ root: 'src', fail: true });

// Ensure all source files have tests
checkSourceFilesHaveTests({
  root: 'src',
  ignorePattern: /Icon[A-Z][A-Za-z]+\.tsx$/,
  fail: true,
});

// Disable component snapshots
disableComponentSnapshots({
  docsUrl: 'https://example.com/docs/testing',
});

// Disable new JavaScript files
disableNewJavaScript();

API Reference

checkForConventionalPrefix()

Verifies that the PR title contains a conventional changelog prefix according to the conventional-changelog format.

Example:

checkForConventionalPrefix();

Behavior:

• Fails the PR if the title doesn't match the conventional commit format
• Valid formats include: fix:, new(scope):, update(Button):, etc.

checkForConventionalSquashCommit()

Ensures that when a PR has only 1 commit and will be squash-merged, the commit message matches the PR title. This prevents losing the semver prefix during automatic releases.

Example:

checkForConventionalSquashCommit();

Behavior:

• Fails if PR has exactly 1 commit and the commit message doesn't include the PR title
• Prevents semver prefix loss during squash merges

checkForInvalidLocks()

Validates that lock file changes are accompanied by corresponding package.json changes.

Example:

checkForInvalidLocks();

Behavior:

• Fails if package-lock.json is changed without package.json
• Fails if npm-shrinkwrap.json is changed without package.json
• Fails if pnpm-lock.yaml is changed without package.json or pnpm-workspace.yaml

Supported lock files:

• package-lock.json (npm)
• npm-shrinkwrap.json (npm)
• pnpm-lock.yaml (pnpm)

checkForADR(docsPath, options?)

Checks that large PRs have an associated Architecture Decision Record (ADR) file documenting the changes.

Parameters:

• docsPath (string): Path to the ADR documentation directory (e.g., 'docs/adr')
• options (object, optional):
  • changeThreshold (number, default: 200): Number of additions/deletions that trigger the check
  • docsUrl (string, optional): URL to ADR documentation
  • exclusions (string[], optional): Additional file patterns to exclude from change count
  • fail (boolean, default: false): Whether to fail the PR or just warn

Example:

checkForADR('docs/adr', {
  changeThreshold: 200,
  docsUrl: 'https://example.com/docs/adr',
  exclusions: ['*.md'],
  fail: true,
});

Behavior:

• Automatically excludes lock files, test files, and snapshots from change count
• Shows a thank you message if ADR files are found
• Warns or fails if PR exceeds threshold without ADR documentation
• Skips check for revert PRs

checkForAnyTests(options?)

Checks that test files exist when source files are updated.

Parameters:

• options (object, optional):
  • root (string, optional): Root directory to filter source files (e.g., 'src')
  • fail (boolean, default: false): Whether to fail the PR or just warn

Example:

checkForAnyTests({ root: 'src', fail: true });

Behavior:

• Checks if any test files (.test.ts, .test.tsx, .test.js, .test.jsx) are present
• Warns or fails if source files changed but no test files found
• Skips check for revert PRs

checkSourceFilesHaveTests(options?)

Ensures that all touched source files have an accompanying test file change.

Parameters:

• options (object, optional):
  • root (string, optional): Root directory to filter source files
  • ignorePattern (RegExp, optional): Pattern to ignore specific source files
  • fail (boolean, default: false): Whether to fail the PR or just warn

Example:

checkSourceFilesHaveTests({
  root: 'src',
  ignorePattern: /Icon[A-Z][A-Za-z]+\.tsx$/,
  fail: true,
});

Behavior:

• Maps source files to expected test file names:
  • src/components/Button.tsx → tests/components/Button.test.tsx
  • src/components/index.tsx → tests/components/index.test.tsx or tests/components/Button.test.tsx
• Lists all source files missing test files
• Skips check for revert PRs

Test file mapping rules:

• src/ → tests/ or test/
• Foo/index.tsx → Foo.test.tsx or Foo/index.test.tsx
• Foo.tsx → Foo.test.tsx

disableComponentSnapshots(options?)

Prevents creation or updates of component snapshot files (.jsx.snap, .tsx.snap).

Parameters:

• options (object, optional):
  • docsUrl (string, optional): URL to migration documentation

Example:

disableComponentSnapshots({
  docsUrl: 'https://example.com/docs/testing',
});

Behavior:

• Fails if new snapshot files are created
• Warns if existing snapshot files are updated
• Skips check for revert PRs

disableNewJavaScript()

Prevents creation of new JavaScript files, enforcing TypeScript usage.

Example:

disableNewJavaScript();

Behavior:

• Fails if any new .js or .jsx files are created in src/ or tests?/ directories
• Only checks newly created files, not modified files

Types

CommonOptions

interface CommonOptions {
  fail?: boolean; // Whether to fail the PR (true) or warn (false)
}

CheckAdrOptions

interface CheckAdrOptions extends CommonOptions {
  changeThreshold?: number; // Default: 200
  docsUrl?: string;
  exclusions?: string[];
}

TestOptions

interface TestOptions extends CommonOptions {
  ignorePattern?: RegExp;
  root?: string;
}

SnapshotOptions

interface SnapshotOptions {
  docsUrl?: string;
}

Helper Functions

The following helper functions are exported but primarily used internally:

• debug(msg, ...args): Debug logging (only when dangerfile.js is modified)
• isRevert(): Checks if PR is a revert
• countChangesInFile(file): Counts additions/deletions in a file
• touchedFiles: Array of all created, deleted, and modified files
• updatedFiles: Array of all created and modified files

Constants

• IS_SRC: Regex matching src/ directory
• IS_TEST: Regex matching tests?/ directory
• JS_EXT: Regex matching .js or .jsx files
• SRC_EXT: Regex matching .ts, .tsx, .js, .jsx files
• TEST_EXT: Regex matching .test.ts, .test.tsx, .test.js, .test.jsx files
• SNAP_EXT: Regex matching .snap files
• GLOBAL_IGNORE: Regex for globally ignored files (e.g., icon components)