From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 11 Dec 2023 15:55:25 +0000 (-0500)
Subject: restore ValueError when greenlet not installed
X-Git-Tag: rel_2_0_24~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9528b5977d97993df8c8fe47121ddb8a98dee95a;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

restore ValueError when greenlet not installed

continuing for #10747, add a test asserting we dont get an
endless loop and get a clean ValueError instead when greenlet not
installed and async functions are used.

Fixes: #10747
Change-Id: I54dffe8577025e2ef3a59f5ca9ab7f4362d4d91f
(cherry picked from commit 35a0854cae1e23271963e7781c65495e9c84f872)
---

diff --git a/lib/sqlalchemy/testing/requirements.py b/lib/sqlalchemy/testing/requirements.py
index 5d1f3fb166..4dd5176a3e 100644
--- a/lib/sqlalchemy/testing/requirements.py
+++ b/lib/sqlalchemy/testing/requirements.py
@@ -1609,6 +1609,18 @@ class SuiteRequirements(Requirements):
     def asyncio(self):
         return self.greenlet
 
+    @property
+    def no_greenlet(self):
+        def go(config):
+            try:
+                import greenlet  # noqa: F401
+            except ImportError:
+                return True
+            else:
+                return False
+
+        return exclusions.only_if(go)
+
     @property
     def greenlet(self):
         def go(config):
diff --git a/test/base/test_concurrency_py3k.py b/test/base/test_concurrency_py3k.py
index b4fb34d025..63a9f85080 100644
--- a/test/base/test_concurrency_py3k.py
+++ b/test/base/test_concurrency_py3k.py
@@ -264,3 +264,18 @@ class TestAsyncAdaptedQueue(fixtures.TestBase):
         t.join()
 
         is_true(run[0])
+
+
+class GracefulNoGreenletTest(fixtures.TestBase):
+    __requires__ = ("no_greenlet",)
+
+    def test_await_only_graceful(self):
+        async def async_fn():
+            pass
+
+        with expect_raises_message(
+            ValueError,
+            "the greenlet library is required to use this "
+            "function. No module named 'greenlet'",
+        ):
+            await_only(async_fn())