View Source Credo.Check.Warning.UnusedStringOperation (Credo v1.7.2-rc.4)
This check has a base priority of high
and works with any version of Elixir.
Explanation
The result of a call to the String module's functions has to be used.
While this is correct ...
def salutation(username) do
username = String.downcase(username)
"Hi #{username}"
end
... we forgot to save the downcased username in this example:
# This is bad because it does not modify the username variable!
def salutation(username) do
String.downcase(username)
"Hi #{username}"
end
Since Elixir variables are immutable, String operations never work on the variable you pass in, but return a new variable which has to be used somehow.
Check-Specific Parameters
There are no specific parameters for this check.
General Parameters
Like with all checks, general params can be applied.
Parameters can be configured via the .credo.exs
config file.