Bylaw.Credo.Check.Elixir.NoTryRescue (bylaw_credo v0.1.0-alpha.1)

Basics

This check has a base priority of higher and works with any version of Elixir.

Explanation

Avoid try/rescue and try/catch for ordinary control flow.

Examples

Avoid:

  try do
    Accounts.fetch_user!(id)
  rescue
    Ecto.NoResultsError -> {:error, :not_found}
  end

Prefer:

  case Accounts.fetch_user(id) do
    {:ok, user} -> {:ok, user}
    {:error, :not_found} -> {:error, :not_found}
  end

Notes

Exceptions hide expected failure modes and make the successful path look more reliable than it is. They also push error handling away from the function contract.

Prefer functions that return explicit values and handle those values with pattern matching. try/after without rescue or catch is still allowed for resource cleanup.

This check uses static AST analysis, so it favors clear source-level patterns over runtime behavior.

Options

This check has no check-specific options. Configure it with an empty option list.

Usage

Add this check to Credo's checks: list in .credo.exs:

%{
  configs: [
    %{
      name: "default",
      checks: [
        {Bylaw.Credo.Check.Elixir.NoTryRescue, []}
      ]
    }
  ]
}

Check-Specific Parameters

There are no specific parameters for this check.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.