Mix Elixir Tooling

Resumo (pt-BR): Após editar arquivos Elixir, rodar format, credo e compile com warnings-as-errors. Usar mix precommit quando o projeto definir esse alias.

When working on Elixir files, use the Mix toolchain to keep code consistent and error-free.

When to Use

After editing any .ex or .exs file
Before committing Elixir changes
When the user asks to "format", "lint", "check code quality", or "fix compile warnings" in an Elixir project

Tools (in order)

1. mix format

Formats all Elixir source files according to the project's .formatter.exs.

mix format

Run after editing code to keep style consistent. The project may format specific paths; use mix format path/to/file.ex for a single file.

2. mix credo

Runs Credo for code quality and consistency (if the project has Credo in deps).

mix credo
# Or for a single file:
mix credo path/to/file.ex

Run after edits to catch style issues, duplication, and suggested refactors. If Credo is not in mix.exs, skip this step.

3. mix compile --warnings-as-errors

Ensures the project compiles and treats warnings as errors.

mix compile --warnings-as-errors

Run to catch compile-time warnings before they accumulate. Fix any reported warnings.

Project alias: mix precommit

If the project defines a precommit alias in mix.exs (e.g. format + credo + compile), prefer:

mix precommit

Use this when the project documents it (e.g. in AGENTS.md or README) so one command runs the full checks.

Process

After making changes to Elixir files, run mix format (or mix precommit if available).
If Credo is in the project, run mix credo and address reported issues.
Run mix compile --warnings-as-errors and fix any warnings.
If the project uses mix precommit, running it once may cover all of the above.

Notes

Don't assume Credo is present; check mix.exs or run mix help credo.
Format and compile are standard; Credo is optional and project-specific.
Always fix compile warnings; do not leave them for later.

mix-elixir-tooling