Use latest dependencies for Testbed testing

.github/dependabot.yml

@@ -72,3 +72,14 @@ updates:
       interval: "weekly"
       day: "sunday"
       time: "20:00"
+
+  - package-ecosystem: "pip"
+    directory: "/testbed"
+    ignore:
+      # pin PIL for Android and iOS
+      - dependency-name: "pillow"
+    schedule:
+      # Check for updates on Sunday, 8PM UTC
+      interval: "weekly"
+      day: "sunday"
+      time: "20:00"

changes/2382.misc.rst

@@ -0,0 +1 @@
+The Testbed tests were updated to use the latest testing dependencies.

testbed/pyproject.toml

@@ -1,8 +1,23 @@
-# This project was generated using template: https://github.com/beeware/briefcase-template and branch: v0.3.12
+[project]
+name = "testbed"
+version = "0.0.1"
+dependencies = ["../core"]
+
+[project.optional-dependencies]
+test = [
+    "coverage==7.5.3",
+    # fonttools is only needed by Android, but we need to use
+    # sys.platform == 'linux' as there's no dependency identifier
+    # that can target Android exclusively until 3.13 lands.
+    "fonttools==4.53.0 ; sys.platform == 'linux'",
+    "pillow==9.2.0",
+    "pytest==8.2.2",
+    "pytest-asyncio==0.23.7",
+]
+
 [tool.briefcase]
 project_name = "Toga Testbed"
 bundle = "org.beeware.toga"
-version = "0.0.1"
 url = "https://beeware.org"
 license.file = "LICENSE"
 author = "Tiberius Yak"
@@ -18,15 +33,6 @@ sources = [
 test_sources = [
     "tests",
 ]
-requires = [
-    "../core",
-]
-test_requires = [
-    "coverage==7.2.0",
-    "pytest==7.2.0",
-    "pytest-asyncio==0.20.3",
-    "pillow==9.2.0",
-]
 
 permission.camera = "The testbed needs to exercise Camera APIs"
 permission.fine_location = "The testbed needs to exercise fine-grained geolocation services."
@@ -76,9 +82,6 @@ test_sources = [
 requires = [
     "../android",
 ]
-test_requires = [
-    "fonttools==4.42.1",
-]
 
 base_theme = "Theme.MaterialComponents.Light.DarkActionBar"
 

testbed/tests/conftest.py

@@ -69,14 +69,22 @@ async def main_window_probe(app, main_window):
 
 # Controls the event loop used by pytest-asyncio.
 @fixture(scope="session")
-def event_loop(app):
-    loop = ProxyEventLoop(app._impl.loop)
-    yield loop
-    loop.close()
+def event_loop_policy(app):
+    yield ProxyEventLoopPolicy(ProxyEventLoop(app._impl.loop))
 
 
-# Proxy which forwards all tasks to another event loop in a thread-safe manner. It
-# implements only the methods used by pytest-asyncio.
+# Loop policy that ensures proxy loop is always used.
+class ProxyEventLoopPolicy(asyncio.DefaultEventLoopPolicy):
+    def __init__(self, proxy_loop: "ProxyEventLoop"):
+        super().__init__()
+        self._proxy_loop = proxy_loop
+
+    def new_event_loop(self):
+        return self._proxy_loop
+
+
+# Proxy which forwards all tasks to another event loop in a thread-safe manner.
+# It implements only the methods used by pytest-asyncio.
 @dataclass
 class ProxyEventLoop(asyncio.AbstractEventLoop):
     loop: object