Just use coveralls package. See coverallsapp/github-action#4

.github/workflows/testing.yml

@@ -32,7 +32,7 @@ jobs:
           mypy --strict --ignore-missing-imports proxy.py plugin_examples.py tests.py setup.py
       - name: Run Tests
         run: coverage3 run --source=proxy,plugin_examples tests.py
-      - name: Coveralls GitHub Action
-        uses: coverallsapp/github-action@v1.0.1
-        with:
-          github-token: ${{ secrets.github_token }}
+      - name: Coveralls
+        env:
+          COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}
+        run: coveralls

proxy.py

@@ -2258,9 +2258,11 @@ def handle_events(self, readables: List[Union[int, _HasFileno]], writables: List
             if teardown:
                 return True
 
-        # Teardown if client buffer is empty and connection is inactive
-        if not self.client.has_buffer() and \
-                self.is_connection_inactive():
+        # Teardown if client connection has been closed or
+        # if client buffer is empty and connection is inactive
+        if self.client.closed or (
+                not self.client.has_buffer() and
+                self.is_connection_inactive()):
             self.client.queue(build_http_response(
                 httpStatusCodes.REQUEST_TIMEOUT, reason=b'Request Timeout',
                 headers={
@@ -2272,7 +2274,6 @@ def handle_events(self, readables: List[Union[int, _HasFileno]], writables: List
                 'Client buffer is empty and maximum inactivity has reached '
                 'between client and server connection, tearing down...')
             return True
-
         return False
 
     def run_once(self) -> bool: