From 794c98518d4655fa326ef505e6982546d2b18abe Mon Sep 17 00:00:00 2001
From: Eric Wieser <wieser.eric@gmail.com>
Date: Fri, 28 Aug 2020 18:35:39 +0100
Subject: [PATCH 1/2] Fix sympy.testing.pytest.raises to behave like
 pytest.raises

Code written as `assert raises(...)` would pass in pytest and fail in sympy, because sympy was not returning an appropriate object from `raises`.
---
 sympy/multipledispatch/tests/test_core.py       |  4 +---
 sympy/multipledispatch/tests/test_dispatcher.py |  8 +-------
 sympy/testing/pytest.py                         | 14 ++++++++++++--
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/sympy/multipledispatch/tests/test_core.py b/sympy/multipledispatch/tests/test_core.py
index d5df0bd605a7..c8e60caf5f0d 100644
--- a/sympy/multipledispatch/tests/test_core.py
+++ b/sympy/multipledispatch/tests/test_core.py
@@ -2,7 +2,7 @@
 
 from sympy.multipledispatch import dispatch
 from sympy.multipledispatch.conflict import AmbiguityWarning
-from sympy.testing.pytest import raises, XFAIL, warns
+from sympy.testing.pytest import raises, warns
 from functools import partial
 
 test_namespace = dict()  # type: Dict[str, Any]
@@ -11,7 +11,6 @@
 dispatch = partial(dispatch, namespace=test_namespace)
 
 
-@XFAIL
 def test_singledispatch():
     @dispatch(int)
     def f(x): # noqa:F811
@@ -66,7 +65,6 @@ def f(x): # noqa:F811
     assert f(C()) == 'a'
 
 
-@XFAIL
 def test_inheritance_and_multiple_dispatch():
     @dispatch(A, A)
     def f(x, y): # noqa:F811
diff --git a/sympy/multipledispatch/tests/test_dispatcher.py b/sympy/multipledispatch/tests/test_dispatcher.py
index 28732cae068a..b980a8b19afc 100644
--- a/sympy/multipledispatch/tests/test_dispatcher.py
+++ b/sympy/multipledispatch/tests/test_dispatcher.py
@@ -1,7 +1,7 @@
 from sympy.multipledispatch.dispatcher import (Dispatcher, MDNotImplementedError,
                                          MethodDispatcher, halt_ordering,
                                          restart_ordering)
-from sympy.testing.pytest import raises, XFAIL, warns
+from sympy.testing.pytest import raises, warns
 
 
 def identity(x):
@@ -88,7 +88,6 @@ def on_ambiguity(dispatcher, amb):
     assert ambiguities[0]
 
 
-@XFAIL
 def test_raise_error_on_non_class():
     f = Dispatcher('f')
     assert raises(TypeError, lambda: f.add((1,), inc))
@@ -165,7 +164,6 @@ def two(x, y):
     assert 'x - y' in f._source(1.0, 1.0)
 
 
-@XFAIL
 def test_source_raises_on_missing_function():
     f = Dispatcher('f')
 
@@ -197,13 +195,11 @@ def func(*args):
     assert set(f.ordering) == {(int, object), (object, int)}
 
 
-@XFAIL
 def test_no_implementations():
     f = Dispatcher('f')
     assert raises(NotImplementedError, lambda: f('hello'))
 
 
-@XFAIL
 def test_register_stacking():
     f = Dispatcher('f')
 
@@ -238,7 +234,6 @@ class MyList(list):
     assert f.dispatch(int, int) is add
 
 
-@XFAIL
 def test_not_implemented():
     f = Dispatcher('f')
 
@@ -259,7 +254,6 @@ def _(x):
     assert raises(NotImplementedError, lambda: f(1, 2))
 
 
-@XFAIL
 def test_not_implemented_error():
     f = Dispatcher('f')
 
diff --git a/sympy/testing/pytest.py b/sympy/testing/pytest.py
index 174fc590a035..2e8744ac4475 100644
--- a/sympy/testing/pytest.py
+++ b/sympy/testing/pytest.py
@@ -34,6 +34,15 @@
     # Not using pytest so define the things that would have been imported from
     # there.
 
+    # _pytest._code.code.ExceptionInfo
+    class ExceptionInfo:
+        def __init__(self, value):
+            self.value = value
+
+        def __repr__(self):
+            return "<ExceptionInfo {!r}>".format(self.value)
+
+
     def raises(expectedException, code=None):
         """
         Tests that ``code`` raises the exception ``expectedException``.
@@ -54,6 +63,7 @@ def raises(expectedException, code=None):
         >>> from sympy.testing.pytest import raises
 
         >>> raises(ZeroDivisionError, lambda: 1/0)
+        <ExceptionInfo ZeroDivisionError('division by zero')>
         >>> raises(ZeroDivisionError, lambda: 1/2)
         Traceback (most recent call last):
         ...
@@ -92,8 +102,8 @@ def raises(expectedException, code=None):
         elif callable(code):
             try:
                 code()
-            except expectedException:
-                return
+            except expectedException as e:
+                return ExceptionInfo(e)
             raise Failed("DID NOT RAISE")
         elif isinstance(code, str):
             raise TypeError(

From 5ff9c4b33d1f7f31c875ecac4f6ff26d0f749ec4 Mon Sep 17 00:00:00 2001
From: Eric Wieser <wieser.eric@gmail.com>
Date: Sun, 30 Aug 2020 13:40:44 +0100
Subject: [PATCH 2/2] Update sympy/testing/pytest.py

---
 sympy/testing/pytest.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sympy/testing/pytest.py b/sympy/testing/pytest.py
index 2e8744ac4475..11abbad3fe04 100644
--- a/sympy/testing/pytest.py
+++ b/sympy/testing/pytest.py
@@ -63,7 +63,7 @@ def raises(expectedException, code=None):
         >>> from sympy.testing.pytest import raises
 
         >>> raises(ZeroDivisionError, lambda: 1/0)
-        <ExceptionInfo ZeroDivisionError('division by zero')>
+        <ExceptionInfo ZeroDivisionError(...)>
         >>> raises(ZeroDivisionError, lambda: 1/2)
         Traceback (most recent call last):
         ...