From 2101bca8263998fdf21493bd8874963411ad551b Mon Sep 17 00:00:00 2001
From: Sylvain MARIE <sylvain.marie@se.com>
Date: Fri, 7 Jan 2022 15:30:37 +0100
Subject: [PATCH] Fixed an issue where using `partial` on a generator function
 in python 3.5 was raising a `SyntaxError`. Fixed #79

---
 ..._latest_py.py => _main_py35_and_higher.py} | 19 --------------
 src/makefun/_main_py36_and_higher.py          | 26 +++++++++++++++++++
 src/makefun/main.py                           |  4 +--
 tests/test_partial_and_macros.py              | 22 ++++++++++++----
 4 files changed, 45 insertions(+), 26 deletions(-)
 rename src/makefun/{_main_latest_py.py => _main_py35_and_higher.py} (62%)
 create mode 100644 src/makefun/_main_py36_and_higher.py

diff --git a/src/makefun/_main_latest_py.py b/src/makefun/_main_py35_and_higher.py
similarity index 62%
rename from src/makefun/_main_latest_py.py
rename to src/makefun/_main_py35_and_higher.py
index ecf497e..df89eda 100644
--- a/src/makefun/_main_latest_py.py
+++ b/src/makefun/_main_py35_and_higher.py
@@ -22,22 +22,3 @@ def partial_f(*args, **kwargs):
         kwargs.update(preset_kwargs)  # for python 3.4: explicit dict update
         yield from f(*chain(preset_pos_args, args), **kwargs)
     return partial_f
-
-
-def make_partial_using_async_for_in_yield(new_sig, f, *preset_pos_args, **preset_kwargs):
-    """
-    Makes a 'partial' when f is a async generator and python is new enough to support `async for v in f(): yield v`
-
-    :param new_sig:
-    :param f:
-    :param presets:
-    :return:
-    """
-
-    @wraps(f, new_sig=new_sig)
-    async def partial_f(*args, **kwargs):
-        kwargs.update(preset_kwargs)
-        async for v in f(*chain(preset_pos_args, args), **kwargs):
-            yield v
-
-    return partial_f
diff --git a/src/makefun/_main_py36_and_higher.py b/src/makefun/_main_py36_and_higher.py
new file mode 100644
index 0000000..c799e33
--- /dev/null
+++ b/src/makefun/_main_py36_and_higher.py
@@ -0,0 +1,26 @@
+# Authors: Sylvain MARIE <sylvain.marie@se.com>
+#          + All contributors to <https://github.com/smarie/python-makefun>
+#
+# License: 3-clause BSD, <https://github.com/smarie/python-makefun/blob/master/LICENSE>
+from itertools import chain
+
+from makefun.main import wraps
+
+
+def make_partial_using_async_for_in_yield(new_sig, f, *preset_pos_args, **preset_kwargs):
+    """
+    Makes a 'partial' when f is a async generator and python is new enough to support `async for v in f(): yield v`
+
+    :param new_sig:
+    :param f:
+    :param presets:
+    :return:
+    """
+
+    @wraps(f, new_sig=new_sig)
+    async def partial_f(*args, **kwargs):
+        kwargs.update(preset_kwargs)
+        async for v in f(*chain(preset_pos_args, args), **kwargs):
+            yield v
+
+    return partial_f
diff --git a/src/makefun/main.py b/src/makefun/main.py
index 5aa3073..40c366f 100644
--- a/src/makefun/main.py
+++ b/src/makefun/main.py
@@ -1127,13 +1127,13 @@ def partial(f,                 # type: Callable
 
     if _is_generator_func(f):
         if sys.version_info >= (3, 3):
-            from makefun._main_latest_py import make_partial_using_yield_from
+            from makefun._main_py35_and_higher import make_partial_using_yield_from
             partial_f = make_partial_using_yield_from(new_sig, f, *preset_pos_args, **preset_kwargs)
         else:
             from makefun._main_legacy_py import make_partial_using_yield
             partial_f = make_partial_using_yield(new_sig, f, *preset_pos_args, **preset_kwargs)
     elif isasyncgenfunction(f) and sys.version_info >= (3, 6):
-        from makefun._main_latest_py import make_partial_using_async_for_in_yield
+        from makefun._main_py36_and_higher import make_partial_using_async_for_in_yield
         partial_f = make_partial_using_async_for_in_yield(new_sig, f, *preset_pos_args, **preset_kwargs)
     else:
         @wraps(f, new_sig=new_sig)
diff --git a/tests/test_partial_and_macros.py b/tests/test_partial_and_macros.py
index 1fc9e21..6fd4503 100644
--- a/tests/test_partial_and_macros.py
+++ b/tests/test_partial_and_macros.py
@@ -174,10 +174,19 @@ def f(a, b, c, **d):
         # assert str(signature(fp_ref)) == str(signature(fp))
 
 
-def test_simple_partial_copy():
-    """Test that when not providing any argument to partial, it is equivalent to wraps with new sig = None"""
-    def f1(a):
-        return a + 1
+@pytest.mark.parametrize("is_generator", [False, True])
+def test_simple_partial_copy(is_generator):
+    """Test that when not providing any argument to partial, it is equivalent to wraps with new sig = None
+
+    This test was extended to cover issue 79.
+    """
+
+    if is_generator:
+        def f1(a):
+            yield a + 1
+    else:
+        def f1(a):
+            return a + 1
 
     f2 = makefun.partial(f1)
 
@@ -188,7 +197,10 @@ def f1(a):
     f3 = makefun.wraps(f1)(f1)
     assert f3.__wrapped__ == f1
 
-    assert f2(1) == f3(1) == 2
+    if is_generator:
+        assert next(f2(1)) == next(f3(1)) == 2
+    else:
+        assert f2(1) == f3(1) == 2
 
     # the func attribute is there too
     f4 = functools.partial(f1)