From 53bc524b7eb0801d2900aede0e2141a3c482423f Mon Sep 17 00:00:00 2001
From: Ram Rachum <ram@rachum.com>
Date: Fri, 13 Sep 2019 20:08:33 +0300
Subject: [PATCH] Reject coroutine functions and async generator functions #152

---
 pysnooper/pycompat.py |  5 ++++
 pysnooper/tracer.py   |  3 +-
 tests/test_async.py   | 69 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 tests/test_async.py

diff --git a/pysnooper/pycompat.py b/pysnooper/pycompat.py
index 1748ccd..ce7566e 100644
--- a/pysnooper/pycompat.py
+++ b/pysnooper/pycompat.py
@@ -47,6 +47,11 @@ try:
 except AttributeError:
     iscoroutinefunction = lambda whatever: False # Lolz
 
+try:
+    isasyncgenfunction = inspect.isasyncgenfunction
+except AttributeError:
+    isasyncgenfunction = lambda whatever: False # Lolz
+
 
 if PY3:
     string_types = (str,)
diff --git a/pysnooper/tracer.py b/pysnooper/tracer.py
index f9625c3..b1b1a16 100644
--- a/pysnooper/tracer.py
+++ b/pysnooper/tracer.py
@@ -267,7 +267,8 @@ class Tracer:
                     method, incoming = gen.throw, e
 
         if pycompat.iscoroutinefunction(function):
-            # return decorate(function, coroutine_wrapper)
+            raise NotImplementedError
+        if pycompat.isasyncgenfunction(function):
             raise NotImplementedError
         elif inspect.isgeneratorfunction(function):
             return generator_wrapper
diff --git a/tests/test_async.py b/tests/test_async.py
new file mode 100644
index 0000000..3a7e477
--- /dev/null
+++ b/tests/test_async.py
@@ -0,0 +1,69 @@
+# Copyright 2019 Ram Rachum and collaborators.
+# This program is distributed under the MIT license.
+
+import io
+import textwrap
+import threading
+import collections
+import types
+import os
+import sys
+
+from pysnooper.utils import truncate
+import pytest
+
+import pysnooper
+from pysnooper.variables import needs_parentheses
+from pysnooper import pycompat
+from .utils import (assert_output, assert_sample_output, VariableEntry,
+                    CallEntry, LineEntry, ReturnEntry, OpcodeEntry,
+                    ReturnValueEntry, ExceptionEntry, SourcePathEntry)
+from . import mini_toolbox
+
+
+def test_rejecting_coroutine_functions():
+    if sys.version_info[:2] <= (3, 4):
+        pytest.skip()
+
+    class Thing:
+        pass
+
+    thing = Thing()
+
+    code = textwrap.dedent('''
+    async def foo(x):
+        return 'lol'
+    thing.foo = foo
+    ''')
+    exec(code)
+    foo = thing.foo
+
+    assert pycompat.iscoroutinefunction(foo)
+    assert not pycompat.isasyncgenfunction(foo)
+    with pytest.raises(NotImplementedError):
+        pysnooper.snoop()(foo)
+
+
+def test_rejecting_async_generator_functions():
+    if sys.version_info[:2] <= (3, 6):
+        pytest.skip()
+
+    class Thing:
+        pass
+
+    thing = Thing()
+
+    code = textwrap.dedent('''
+    async def foo(x):
+        yield 'lol'
+    thing.foo = foo
+    ''')
+    exec(code)
+    foo = thing.foo
+
+    assert not pycompat.iscoroutinefunction(foo)
+    assert pycompat.isasyncgenfunction(foo)
+    with pytest.raises(NotImplementedError):
+        pysnooper.snoop()(foo)
+
+