RuboCop YAML

RuboCop YAML brings deterministic YAML syntax, style, schema, and Rails-configuration checks into RuboCop while preserving comments, anchors, aliases, and document structure.

Version 0.1.0 is the first public release. Its existing semantics are the baseline for real-world dogfooding; new behavior should be driven by confirmed usage rather than speculative fixtures.

• Ruby 3.2 or newer
• RuboCop 1.72 or newer and earlier than 2.0

The gem is framework-independent. Rails is not a runtime dependency; Rails-specific cops operate on configuration files by path and structure.

Add the gem to the development and test groups in your Gemfile:

group :development, :test do
  gem "rubocop-yaml", "~> 0.1", require: false
end

Run bundle install, then register the plugin in .rubocop.yml:

plugins:
  - rubocop-yaml

RuboCop YAML automatically includes **/*.yml and **/*.yaml files.

Configure explicit key order without enabling autocorrection:

YAML/Style/KeyOrdering:
  Enabled: true
  EnforcedStyle: configured
  Keys:
    - name
    - image
    - environment
    - volumes

Map project files to local JSON Schemas:

YAML/Schema/Validation:
  Enabled: true
  Schemas:
    "config/services/*.yml": "schemas/service.json"

With AutoDetect: true, schema validation recognizes Compose files and .github/workflows/*.yml using pinned, vendored schemas. Explicit Schemas mappings take precedence.

Customize Rails database expectations when an application uses nonstandard environments or inherited keys:

YAML/Rails/DatabaseEnvironmentConsistency:
  RequiredEnvironments:
    - development
    - test
    - staging
    - production
  RequiredKeys:
    - adapter
    - database
  AllowMergeKeys: true

• No cop autocorrects YAML in 0.1.0. Rewriting YAML safely across comments, aliases, anchors, merge keys, and ordering semantics requires dedicated research.
• Schema validation never retrieves remote references implicitly. Use local, reviewed schemas.
• The schema registry currently autodetects only Docker Compose and GitHub Actions workflows.
• The Rails database cop analyzes YAML statically. ERB-looking content is preserved as scalar text and never executed.
• Ordering and grouping cops skip mappings with complex or merge keys when enforcing an order could misrepresent YAML semantics.
• Parsing follows the Psych behavior supplied by the active Ruby version; parser edge cases will be expanded through dogfooding and a dedicated torture suite.

Run bin/setup, then bin/ci. Use bin/rspec and bin/rubocop with passthrough arguments for focused checks.

bin/package builds the gem and verifies that runtime configuration, vendored schemas, Ruby code, and RBS signatures are present. bin/e2e installs that artifact into an isolated gem home and proves RuboCop plugin discovery against a Rails-shaped fixture outside the repository load path.

See the documentation index for architecture notes and the release runbook for trusted-publishing setup and release verification.

• lib/ contains the plugin, cops, and public API.
• config/ contains default RuboCop configuration and pinned schemas.
• sig/ contains public RBS contracts.
• spec/ contains behavior, integration, and coverage checks.
• docs/ contains architecture and release documentation.
• bin/ contains repeatable development, package, and external-fixture commands.

RuboCop YAML is available under the MIT License.

Source: github.com/scarver2/rubocop-yaml

— Stan Carver II Made in Texas 🤠 https://stancarver.com