View Source Credo.Check.Refactor.MatchInCondition (Credo v1.7.2-rc.4)
This check has a base priority of 0
and works with any version of Elixir.
Explanation
Pattern matching should only ever be used for simple assignments
inside if
and unless
clauses.
While this fine:
# okay, simple wildcard assignment:
if contents = File.read!("foo.txt") do
do_something(contents)
end
the following should be avoided, since it mixes a pattern match with a condition and do/else blocks.
# considered too "complex":
if {:ok, contents} = File.read("foo.txt") do
do_something(contents)
end
# also considered "complex":
if allowed? && ( contents = File.read!("foo.txt") ) do
do_something(contents)
end
If you want to match for something and execute another block otherwise,
consider using a case
statement:
case File.read("foo.txt") do
{:ok, contents} ->
do_something()
_ ->
do_something_else()
end
Check-Specific Parameters
Use the following parameters to configure this check:
:allow_tagged_tuples
Allow tagged tuples in conditions, e.g. if {:ok, contents} = File.read( "foo.txt") do
This parameter defaults to false
.
General Parameters
Like with all checks, general params can be applied.
Parameters can be configured via the .credo.exs
config file.