CukeDedup

CukeDedup is a fast static analyzer for duplicate, ambiguous, reusable, and unused Cucumber/Gherkin step definitions. It reads project configuration and test code without executing either one.

It supports:

• JavaScript, JSX, TypeScript, and TSX step definitions; experimental, opt-in Cucumber-Ruby support.
• Cucumber.js, Playwright-BDD, Cypress Cucumber, Jest-Cucumber, and Vitest Cucumber Plugin projects.
• Classic .feature files and Gherkin Markdown .feature.md files.
• Terminal, JSON, JSON Lines, HTML, and SARIF reports.
• Thresholds, baselines, changed-file analysis, suppressions, and ignore files.

Ruby support is experimental. Select a single Ruby suite explicitly with --definitions 'features/**/*.rb' --features 'features/**/*.feature', include its support files, and review findings before acting on them. See the supported subset and known limitations.

Install

With Cargo:

cargo install cuke-dedup

Or in a JavaScript project, using Node.js 24 LTS (recommended):

npm install --save-dev cuke-dedup
npx cuke-dedup .

Building from source requires Rust 1.90 or newer:

cargo build --release --locked

Quick start

Run CukeDedup from the root of a test project:

cuke-dedup .

No configuration is required. CukeDedup respects .gitignore and .cuke-dedupignore, skips common generated directories, discovers conventional Gherkin and JavaScript/TypeScript files, and recognizes common Given, When, Then, and defineStep registrations and aliases.

Useful commands:

cuke-dedup . --threshold 5
cuke-dedup . --print-config
cuke-dedup . --reporters terminal,json,html,sarif
cuke-dedup . --reporters jsonl
cuke-dedup . --output reports/cuke-dedup

cuke-dedup check . is equivalent to cuke-dedup .. The explicit check form requires a path; use cuke-dedup ./check to analyze a directory literally named check.

Framework support

Package entrypoints are matched exactly. Plain Playwright projects are supported when their Gherkin bindings use Cucumber.js or Playwright-BDD.

See Discovery and frameworks for configuration detection, monorepo boundaries, module resolution, and incomplete-corpus behavior.

Configuration

CukeDedup reads an explicit --config file, an auto-discovered CukeDedup configuration, or supported framework configuration. CLI flags always have the highest precedence.

A minimal .cuke-dedup.json might be:

{
  "definitions": ["features/steps/**/*.ts"],
  "features": ["features/**/*.{feature,feature.md}"],
  "exclude": ["dist/**"],
  "threshold": 5,
  "reporters": ["terminal", "html"]
}

Use .cuke-dedupignore for repository-specific exclusions:

features/generated/*
**/*.generated.ts
!features/generated/reviewed.generated.ts

See the configuration reference for precedence, every setting, glob semantics, suppressions, and discovery diagnostics.

Findings and reports

CukeDedup detects eight classes of duplication, ambiguity, reuse, and unused definitions. Exact collisions default to errors; heuristic findings default to warnings. See the rule reference for the meaning, default severity, and remediation guidance for every rule.

JSON, HTML, and SARIF files default to reports/cuke-dedup/. See Reports for schemas, destinations, reproducibility, truncation signals, and reporter-specific behavior.

GitHub Action

The Action downloads a native binary and verifies its checksum and build provenance:

permissions:
  contents: read

steps:
  - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
    with:
      fetch-depth: 0
      persist-credentials: false
  - uses: figueiredoluiz/cuke-dedup@v0.11.0
    with:
      path: .
      threshold: 5
      reporters: terminal,json,html,sarif

For changed-file checks, baselines, report artifacts, outputs, and hardened pinning, see CI and baselines.

Exit codes

Warnings alone do not produce exit code 1.

Agent Skill

CukeDedup includes an Agent Skill for safely interpreting and remediating JSONL findings:

npx skills add figueiredoluiz/cuke-dedup --skill cuke-dedup

From a local checkout, use npx skills add ./skills --skill cuke-dedup.

The installer can target supported coding agents or install globally. Run npx skills add --help for agent and scope options.

Invoke it as $cuke-dedup where supported, or ask the agent to analyze and safely fix duplicate Cucumber step definitions. The skill lives in skills/cuke-dedup and is distributed independently from the Cargo and npm packages.

Documentation

• Configuration
• Discovery and frameworks
• Rules and duplication threshold
• Reports
• CI and baselines
• Safety and limitations

Compatibility

• Building from source requires Rust 1.90 or newer. Node.js 24 LTS is recommended for the npm launcher; Node.js 20 remains the minimum compatible version and is tested in CI.
• Definition extraction supports JavaScript and TypeScript, including JSX and common module variants, plus an explicitly selected subset of Cucumber-Ruby. See Ruby support.
• Static analysis cannot safely resolve every dynamic configuration, matcher, wrapper, or imported handler. CukeDedup reports incomplete analysis instead of treating missing evidence as clean.
• Before version 1.0, configuration and machine-report schemas may change between minor releases.

See Safety and limitations for the complete compatibility contract and resource limits.

Contributing and support

See CONTRIBUTING.md for development commands, corpus guidance, and pull-request expectations. Use the issue templates for reproducible bugs and focused feature requests. Report vulnerabilities privately according to SECURITY.md. Bug reports should include a minimal sanitized fixture with application-specific names, credentials, and source removed.

CukeDedup is an independent project. It is not affiliated with or endorsed by the Cucumber project or its maintainers.

Releases

Release archives include SHA-256 checksums, keyless Sigstore bundles, and GitHub build provenance. Published versions and release notes are maintained in GitHub Releases.

gh attestation verify <archive> \
  --repo figueiredoluiz/cuke-dedup \
  --signer-workflow figueiredoluiz/cuke-dedup/.github/workflows/release.yml

License

MIT