Credo v1.4.0 Credo.Check.Warning.MapGetUnsafePass View Source
This check has a base priority of normal
and works with any version of Elixir.
Explanation
Map.get/2
can lead into runtime errors if the result is passed into a pipe
without a proper default value. This happens when the next function in the
pipe cannot handle nil
values correctly.
Example:
%{foo: [1, 2 ,3], bar: [4, 5, 6]}
|> Map.get(:missing_key)
|> Enum.each(&IO.puts/1)
This will cause a Protocol.UndefinedError
, since nil
isn't Enumerable
.
Often times while iterating over enumerables zero iterations is preferrable
to being forced to deal with an exception. Had there been a []
default
parameter this could have been averted.
If you are sure the value exists and can't be nil, please use Map.fetch!/2
.
If you are not sure, Map.get/3
can help you provide a safe default value.
Configuration parameters
There are no parameters for this check.