From 358c85e74c5e9c73a222268cb34c914c52135497 Mon Sep 17 00:00:00 2001
From: Hynek Schlawack <hs@ox.cx>
Date: Fri, 21 Aug 2020 05:19:15 +0200
Subject: [PATCH] Fix auto-detection of eq/ne in NG APIs (#671)

Fixes #670
---
 src/attr/_next_gen.py  |  2 +-
 tests/test_next_gen.py | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/attr/_next_gen.py b/src/attr/_next_gen.py
index b0aefe310..57e8635b1 100644
--- a/src/attr/_next_gen.py
+++ b/src/attr/_next_gen.py
@@ -28,7 +28,7 @@ def define(
     kw_only=False,
     cache_hash=False,
     auto_exc=True,
-    eq=True,
+    eq=None,
     order=False,
     auto_detect=True,
     getstate_setstate=None,
diff --git a/tests/test_next_gen.py b/tests/test_next_gen.py
index e350498a3..a4460b192 100644
--- a/tests/test_next_gen.py
+++ b/tests/test_next_gen.py
@@ -133,3 +133,18 @@ class F:
 
         with pytest.raises(attr.exceptions.FrozenInstanceError):
             f.x = 2
+
+    def test_auto_detect_eq(self):
+        """
+        auto_detect=True works for eq.
+
+        Regression test for #670.
+        """
+
+        @attr.define
+        class C:
+            def __eq__(self, o):
+                raise ValueError()
+
+        with pytest.raises(ValueError):
+            C() == C()