Credo.Check.Warning.UnusedFileOperation (Credo v1.5.0) View Source

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

Explanation

The result of a call to the File module's functions has to be used.

While this is correct ...

def read_from_cwd(filename) do
  # TODO: use Path.join/2
  filename = File.cwd!() <> "/" <> filename

  File.read(filename)
end

... we forgot to save the result in this example:

def read_from_cwd(filename) do
  File.cwd!() <> "/" <> filename

  File.read(filename)
end

Since Elixir variables are immutable, many File operations don't work on the variable you pass in, but return a new variable which has to be used somehow.

Configuration parameters

There are no specific parameters for this check.

Like with all checks, general params can be applied.

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