Basics

This check is disabled by default.

Learn how to enable it via .credo.exs.

This check is tagged :controversial

This means that this check is more opinionated than others and not for everyone's taste.

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

Explanation

Code should not be copy-pasted in a codebase when there is room to abstract the copied functionality in a meaningful way.

That said, you should by no means "ABSTRACT ALL THE THINGS!".

Sometimes it can serve a purpose to have code be explicit in two places, even if it means the snippets are nearly identical. A good example for this are Database Adapters in a project like Ecto, where you might have nearly identical functions for things like order_by or limit in both the Postgres and MySQL adapters.

In this case, introducing an AbstractAdapter just to avoid code duplication might cause more trouble down the line than having a bit of duplicated code.

Like all Software Design issues, this is just advice and might not be applicable to your project/situation.

Check-Specific Parameters

Use the following parameters to configure this check:

:mass_threshold

The minimum mass which a part of code has to have to qualify for this check.

This parameter defaults to 40.

:nodes_threshold

The number of nodes that need to be found to raise an issue.

This parameter defaults to 2.

:excluded_macros

List of macros to be excluded for this check.

This parameter defaults to [].

General Parameters

Like with all checks, general params can be applied.

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