Support fancy in Gradient

Author: Premwoik

lib/gradient/elixir_fmt.ex

@@ -13,6 +13,8 @@ defmodule Gradient.ElixirFmt do
 
   - `ex_fmt_type_fun`: function to pretty print an type AST in Elixir `(abstract_type() -> iodata())`.
 
+  - `{fancy, boolean()}`: do not use fancy error messages, default: true
+
   - Gradualizer options, but some of them are overwritten by Gradient.
   """
   @behaviour Gradient.Fmt
@@ -244,16 +246,23 @@ defmodule Gradient.ElixirFmt do
   @spec try_highlight_in_context(Types.abstract_expr(), options()) ::
           {:ok, iodata()} | {:error, term()}
   def try_highlight_in_context(expression, opts) do
-    forms = Keyword.get(opts, :forms)
-
-    with :ok <- has_location?(expression),
-         {:ok, path} <- get_ex_file_path(forms),
+    with :ok <- print_fancy?(opts),
+         :ok <- has_location?(expression),
+         {:ok, path} <- get_ex_file_path(opts[:forms]),
          {:ok, code} <- File.read(path) do
       code_lines = String.split(code, ~r/\R/)
       {:ok, highlight_in_context(expression, code_lines, opts)}
     end
   end
 
+  def print_fancy?(opts) do
+    if Keyword.get(opts, :fancy, true) do
+      :ok
+    else
+      {:error, "The fancy mode is turn off"}
+    end
+  end
+
   def has_location?(expression) do
     if elem(expression, 1) == 0 do
       {:error, "The location is missing in the expression"}

lib/mix/tasks/gradient.ex

@@ -16,7 +16,7 @@ defmodule Mix.Tasks.Gradient do
     * `--stop_on_first_error` - stop type checking at the first error
     * `--infer` - infer type information from literals and other language
       constructs,
-    * `--verbose` - show what Gradient is doing
+    * `--verbose` - show what Gradualizer is doing
     * `--no-fancy` - do not use fancy error messages
     * `--fmt-location none` - do not display location for easier comparison
     * `--fmt-location brief` - display location for machine processing