add .formatter.exs + format

lib/display/failure.ex

@@ -3,12 +3,17 @@ defmodule Display.Failure do
 
   @no_value :ex_unit_no_meaningful_value
 
-  def format_failure(%{error: %ExUnit.AssertionError{expr: @no_value, message: message}, file: file, line: line}) do
+  def format_failure(%{
+        error: %ExUnit.AssertionError{expr: @no_value, message: message},
+        file: file,
+        line: line
+      }) do
     """
     #{Paint.cyan("Assertion failed in #{file}:#{line}")}
     #{Paint.red(message)}
     """
   end
+
   def format_failure(%{error: %ExUnit.AssertionError{expr: expr} = error, file: file, line: line}) do
     """
     #{Paint.cyan("Assertion failed in #{file}:#{line}")}
@@ -16,6 +21,7 @@ defmodule Display.Failure do
     """
     |> format_inequality(error)
   end
+
   def format_failure(%{error: error, file: file, line: line}) do
     """
     #{Paint.cyan("Error in #{file}:#{line}")}
@@ -26,22 +32,24 @@ defmodule Display.Failure do
   defp format_inequality(message, %{left: @no_value, right: @no_value}) do
     message
   end
+
   defp format_inequality(message, %{left: @no_value, right: match_value}) do
     """
     #{message}
-    value does not match: #{match_value |> inspect |> Paint.yellow}
+    value does not match: #{match_value |> inspect |> Paint.yellow()}
     """
   end
+
   defp format_inequality(message, %{left: left, right: right}) do
     """
     #{message}
-    left:  #{left |> inspect |> Paint.yellow}
-    right: #{right |> inspect |> Paint.yellow}
+    left:  #{left |> inspect |> Paint.yellow()}
+    right: #{right |> inspect |> Paint.yellow()}
     """
   end
 
   defp format_error(error) do
-    trace = System.stacktrace |> Enum.take(2)
+    trace = System.stacktrace() |> Enum.take(2)
     Paint.red(Exception.format(:error, error, trace))
   end