credo-custom-checks

Custom Credo checks enforce project-specific code quality rules by implementing a Credo.Check module with a run/2 function, traversing the AST using Credo.Code.prewalk, emitting issues via format_issue and IssueMeta, then registering the check in your credo.exs configuration file.

Use custom Credo checks when you need to enforce domain-specific code quality rules, detect hardcoded secrets, prevent anti-patterns, or validate patterns unique to your codebase that the default Credo checks don't cover.

Yes, custom Credo checks apply to static analysis workflows in both CI pipelines and local development environments once registered in credo.exs, enabling consistent code quality enforcement across your entire development lifecycle.

Default Credo rules enforce general Elixir best practices, while custom Credo checks let you define and enforce project-specific patterns, business logic constraints, and organizational standards tailored to your codebase's unique needs.

Basic familiarity with Credo and Elixir AST concepts helps, but custom Credo checks require understanding how to write a Check module, use prewalk for AST traversal, and configure the check in credo.exs—intermediate-level implementation knowledge.

Register custom Credo checks in your .credo.exs file alongside built-in checks, specifying categories and priority levels so they run seamlessly with default rules during static analysis.