# `Mailglass.Credo.NoOversizedUseInjection`
[🔗](https://github.com/szTheory/mailglass/blob/v1.0.0/credo_checks/no_oversized_use_injection.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

`defmacro __using__/1` in Mailglass modules must keep injected code small.
This check counts AST nodes in the returned `quote` body rather than
macro-expanding the injection.

## Check-Specific Parameters

Use the following parameters to configure this check:

### `:max_lines`

  Maximum count of tracked AST forms allowed in `__using__/1`.

*This parameter defaults to* `20`.

## 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*