From e3e712f9ad83fa1968c6fd316372a1b86af3c70a Mon Sep 17 00:00:00 2001
From: Wojtek Mach <wojtek@wojtekmach.pl>
Date: Wed, 16 Feb 2022 14:43:43 +0000
Subject: [PATCH] Support negative integer literals in types

---
 lib/spect.ex          | 4 ++++
 test/spect_test.exs   | 3 +++
 test/support/specs.ex | 1 +
 3 files changed, 8 insertions(+)

diff --git a/lib/spect.ex b/lib/spect.ex
index d54a774..5b48512 100644
--- a/lib/spect.ex
+++ b/lib/spect.ex
@@ -156,6 +156,10 @@ defmodule Spect do
     to_kind!(data, module, type, params)
   end
 
+  defp to_kind!(data, _module, {:op, _, :-, {:integer, _, value}}, _params) do
+    to_lit!(data, :integer, -value)
+  end
+
   defp to_kind!(data, _module, {kind, _line, value}, _params) do
     to_lit!(data, kind, value)
   end
diff --git a/test/spect_test.exs b/test/spect_test.exs
index 4ea4407..dbaf09f 100644
--- a/test/spect_test.exs
+++ b/test/spect_test.exs
@@ -36,6 +36,9 @@ defmodule Spect.Test do
     assert to_spec(1, Specs, :literal_1) === {:ok, 1}
     {:error, %ConvertError{}} = to_spec(2, Specs, :literal_1)
 
+    assert to_spec(-1, Specs, :literal_minus_1) === {:ok, -1}
+    {:error, %ConvertError{}} = to_spec(-2, Specs, :literal_minus_1)
+
     assert to_spec([], Specs, :literal_list) === {:ok, []}
     {:error, %ConvertError{}} = to_spec(1, Specs, :literal_list)
 
diff --git a/test/support/specs.ex b/test/support/specs.ex
index 1ee4b03..f45ca62 100644
--- a/test/support/specs.ex
+++ b/test/support/specs.ex
@@ -6,6 +6,7 @@ defmodule Spect.Support.Specs do
   @type literal_true :: true
   @type literal_false :: false
   @type literal_1 :: 1
+  @type literal_minus_1 :: -1
   @type literal_list :: []
   @type literal_map :: %{}