View Source Credo.Check.Design.DuplicatedCode (Credo v1.6.7)
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.
Link to this section Summary
Functions
Calculates hash values for all sub nodes in a given +ast+.
Returns the mass (count of instructions) for an AST.
Takes a map of hashes to nodes and prunes those nodes that are just subnodes of others in the same set.
Returns a hash-value for a given +ast+.
Link to this section Functions
calculate_hashes(ast, existing_hashes \\ %{}, filename \\ "foo.ex", mass_threshold \\ param_defaults()[:mass_threshold])
View SourceCalculates hash values for all sub nodes in a given +ast+.
Returns a map with the hashes as keys and the nodes as values.
Returns the mass (count of instructions) for an AST.
prune_hashes(given_hashes, mass_threshold \\ param_defaults()[:mass_threshold])
View SourceTakes a map of hashes to nodes and prunes those nodes that are just subnodes of others in the same set.
Returns the resulting map.
Returns a hash-value for a given +ast+.