Small changes

omnikinverter/omnikinverter.py

@@ -76,9 +76,8 @@ async def request(
             "Accept": "text/html,application/xhtml+xml,application/xml",
         }
 
-        if self._session is None:
-            self._session = ClientSession()
-            self._close_session = True
+        # Don't reuse session as Wifi stick does not seem to support it
+        self._session = ClientSession()
 
         auth = None
         if self.username and self.password:
@@ -112,7 +111,10 @@ async def request(
                 {"Content-Type": content_type, "response": text},
             )
 
-        return await response.text()
+        raw_response = await response.read()
+        # Close the client session
+        await self._session.close()
+        return raw_response.decode("ascii", "ignore")
 
     async def inverter(self) -> Inverter:
         """Get values from your Omnik Inverter.

pyproject.toml

@@ -63,7 +63,7 @@ bandit = "^1.7.0"
 Changelog = "https://github.com/klaasnicolaas/python-omnikinverter/releases"
 
 [tool.black]
-target-version = ['py37']
+target-version = ['py38']
 
 [tool.coverage.paths]
 source = ["omnikinverter"]

tests/test_omnik.py

@@ -74,7 +74,7 @@ async def response_handler(_):
     aresponses.add("example.com", "/js/status.js", "GET", response_handler)
 
     async with aiohttp.ClientSession() as session:
-        client = OmnikInverter(host="example.com", session=session)
+        client = OmnikInverter(host="example.com", session=session, request_timeout=0.1)
         with pytest.raises(OmnikInverterConnectionError):
             assert await client.inverter()