# `Bylaw.Credo.Check.Elixir.NoResultTupleArgument`
[🔗](https://github.com/ryanzidago/bylaw/blob/v0.1.0-alpha.1/lib/bylaw/credo/check/elixir/no_result_tuple_argument.ex#L1)

## Basics

> #### This check is disabled by default. {: .neutral}
>
> [Learn how to enable it](`e:credo:config_file.html#checks`) via `.credo.exs`.

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

## Explanation

Prevents functions from accepting `{:ok, _}` or `{:error, _}` as their first
argument.

## Examples

Avoid:

      def handle({:ok, value}), do: process(value)
      def handle({:error, reason}), do: reason

Prefer:

      case fetch_value() do
        {:ok, value} -> process(value)
        {:error, reason} -> reason
      end

## Notes

A helper that accepts tagged result tuples mixes two responsibilities:
branching on the result shape and doing the work for the successful or error
value. That makes the helper harder to reuse with plain values.

Branch where the tagged result is produced, then call helpers with the value
or reason they actually operate on.

Path exclusions are matched against the source filename and are intended for generated files or temporary migration areas.

The check uses static AST analysis, so dynamic code generation and macro-expanded code may fall outside its signal.

## Options

Configure options in `.credo.exs` with the check tuple:

```elixir
%{
  configs: [
    %{
      name: "default",
      checks: [
        {Bylaw.Credo.Check.Elixir.NoResultTupleArgument,
         [
           excluded_paths: ["test/support/"]
         ]}
      ]
    }
  ]
}
```

- `:excluded_paths` - List of paths or regexes to exclude from this check

## Usage

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

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

## Check-Specific Parameters

Use the following parameters to configure this check:

### `:excluded_paths`

  List of paths or regexes to exclude from this check

*This parameter defaults to* `[]`.

## General Parameters

Like with all checks, [general params](`e:credo:check_params.html`) can be applied.

Parameters can be configured via the [`.credo.exs` config file](`e:credo:config_file.html`).

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*Consult [api-reference.md](api-reference.md) for complete listing*