yq/CONTRIBUTING.md

Before you begin

Not all new PRs will be merged in

It's recommended to check with the owner first (e.g. raise an issue) to discuss a new feature before developing, to ensure your hard efforts don't go to waste.

PRs to fix bugs and issues are almost always welcome 🙏 please ensure you write tests as well.

The following types of PRs will not be accepted:

• Significant refactors take a lot of time to understand and can have all sorts of unintended side effects. If you think there's a better way to do things (that requires significant changes) raise an issue for discussion first :)
• Release pipeline PRs are a security risk - it's too easy for a serious vulnerability to sneak in (either intended or not). If there is a new cool way of releasing things, raise an issue for discussion first - it will need to be gone over with a fine tooth comb.
• Version bumps are handled by dependabot, the bot will auto-raise PRs and they will be regularly merged in.
• New release platforms At this stage, yq is not going to maintain any other release platforms other than GitHub and Docker - that said, I'm more than happy to put in other community maintained methods in the README for visibility ❤️

Development

Initial Setup

1. Install Golang (version 1.24.0 or later)
2. Run scripts/devtools.sh to install required development tools:
   • golangci-lint for code linting
   • gosec for security analysis
3. Run make [local] vendor to install vendor dependencies
4. Run make [local] test to ensure you can run the existing tests

Development Workflow

1. Write unit tests first - Changes will not be accepted without corresponding unit tests (see Testing section below)
2. Make your code changes
3. Run tests and linting: make [local] test (this runs formatting, linting, security checks, and tests)
4. Create your PR and get kudos! :)

Make Commands

• Use make [local] <command> for local development (runs in Docker container)
• Use make <command> for CI/CD environments
• Common commands:
  • make [local] vendor - Install dependencies
  • make [local] test - Run all checks and tests
  • make [local] build - Build the yq binary
  • make [local] format - Format code
  • make [local] check - Run linting and security checks

Code Quality

Linting and Formatting

The project uses strict linting rules defined in .golangci.yml. All code must pass:

• Code formatting: gofmt, goimports, gci
• Linting: revive, errorlint, gosec, misspell, and others
• Security checks: gosec security analysis
• Spelling checks: misspell detection

Run make [local] check to verify your code meets all quality standards.

Code Style Guidelines

• Follow standard Go conventions
• Use meaningful variable names
• Add comments for public functions and complex logic
• Keep functions focused and reasonably sized
• Use the project's existing patterns and conventions

Testing

Test Structure

Tests in yq use the expressionScenario pattern. Each test scenario includes:

• expression: The yq expression to test
• document: Input YAML/JSON (optional)
• expected: Expected output
• skipDoc: Whether to skip documentation generation

Writing Tests

1. Find the appropriate test file (e.g., operator_add_test.go for addition operations)
2. Add your test scenario to the *OperatorScenarios slice
3. Run the specific test: go test -run TestAddOperatorScenarios (replace with appropriate test name)
4. Verify documentation generation (see Documentation section)

Test Examples

var addOperatorScenarios = []expressionScenario{
    {
        skipDoc:    true,
        expression: `"foo" + "bar"`,
        expected: []string{
            "D0, P[], (!!str)::foobar\n",
        },
    },
    {
        document:   "apples: 3",
        expression: `.apples + 3`,
        expected: []string{
            "D0, P[apples], (!!int)::6\n",
        },
    },
}

Running Tests

• All tests: make [local] test
• Specific test: go test -run TestName
• With coverage: make [local] cover

Documentation

Documentation Generation

The project uses a documentation system that combines static headers with dynamically generated content from tests.

How It Works

1. Static headers are defined in pkg/yqlib/doc/operators/headers/*.md
2. Dynamic content is generated from test scenarios in *_test.go files
3. Generated docs are created in pkg/yqlib/doc/*.md by concatenating headers with test-generated content
4. Documentation is synced to the gitbook branch for the website

Updating Operator Documentation

For Test-Generated Documentation

Most operator documentation is generated from tests. To update:

1. Find the test file (e.g., operator_add_test.go)
2. Update test scenarios - each expressionScenario with skipDoc: false becomes documentation
3. Run the test to regenerate docs:

   cd pkg/yqlib
   go test -run TestAddOperatorScenarios
   

4. Verify the generated documentation in pkg/yqlib/doc/add.md
5. Create a PR with your changes

For Header-Only Documentation

If documentation exists only in headers/*.md files:

1. Update the header file directly (e.g., pkg/yqlib/doc/operators/headers/add.md)
2. Create a PR with your changes

Updating Static Documentation

For documentation not in the master branch:

1. Check the gitbook branch for additional pages
2. Update the *.md files directly
3. Create a PR to the gitbook branch

Documentation Best Practices

• Write clear, concise examples in test scenarios
• Use meaningful variable names in examples
• Include edge cases and error conditions
• Test your documentation changes by running the specific test
• Verify generated output matches expectations

Note: PRs with small changes (e.g. minor typos) may not be merged (see https://joel.net/how-one-guy-ruined-hacktoberfest2020-drama).

Troubleshooting

Common Setup Issues

Docker/Podman Issues

• Problem: make commands fail with Docker errors
• Solution: Ensure Docker or Podman is running and accessible
• Alternative: Use make local <command> to run in containers

Go Version Issues

• Problem: Build fails with Go version errors
• Solution: Ensure you have Go 1.24.0 or later installed
• Check: Run go version to verify

Vendor Dependencies

• Problem: make vendor fails or dependencies are outdated
• Solution:

  go mod tidy
  make [local] vendor
  

Linting Failures

• Problem: make check fails with linting errors
• Solution:

  make [local] format  # Auto-fix formatting
  # Manually fix remaining linting issues
  make [local] check   # Verify fixes
  

Test Failures

• Problem: Tests fail locally but pass in CI
• Solution:

  make [local] test    # Run in Docker container
  

Documentation Generation Issues

• Problem: Generated docs don't update after test changes
• Solution:

  cd pkg/yqlib
  go test -run TestSpecificOperatorScenarios
  # Check if generated file updated in pkg/yqlib/doc/
  

Getting Help

• Check existing issues: Search GitHub issues for similar problems
• Create an issue: If you can't find a solution, create a detailed issue
• Ask questions: Use GitHub Discussions for general questions
• Join the community: Check the project's community channels