[wdspec] Session fixtures should not ignore "session not created" errors.

Right now we ignore all the possible thrown "session not created"
errors unless the session id is not set. This is specifically
problematic for the BiDi session creation, which would fail
silently in case it cannot be created.

Differential Revision: https://phabricator.services.mozilla.com/D122625

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1725683
gecko-commit: aca153106940b800cac068609f552fc82b2ba2d1
gecko-reviewers: webdriver-reviewers, jgraham

Author: whimboo

tools/webdriver/webdriver/client.py

@@ -1,10 +1,11 @@
+from typing import Dict
+from urllib import parse as urlparse
+
 from . import error
 from . import protocol
 from . import transport
 from .bidi.client import BidiSession
 
-from urllib import parse as urlparse
-
 
 def command(func):
     def inner(self, *args, **kwargs):
@@ -551,6 +552,9 @@ def start(self):
             body["capabilities"] = self.requested_capabilities
 
         value = self.send_command("POST", "session", body=body)
+        assert isinstance(value["sessionId"], str)
+        assert isinstance(value["capabilities"], Dict)
+
         self.session_id = value["sessionId"]
         self.capabilities = value["capabilities"]
 

webdriver/tests/support/fixtures.py

@@ -113,12 +113,8 @@ async def session(capabilities, configuration, request):
             configuration["host"],
             configuration["port"],
             capabilities=caps)
-    try:
-        _current_session.start()
 
-    except webdriver.error.SessionNotCreatedException:
-        if not _current_session.session_id:
-            raise
+    _current_session.start()
 
     # Enforce a fixed default window size and position
     if _current_session.capabilities.get("setWindowRect"):
@@ -159,12 +155,8 @@ async def bidi_session(capabilities, configuration, request):
             capabilities=caps,
             enable_bidi=True)
 
-    try:
-        _current_session.start()
-        await _current_session.bidi_session.start()
-    except webdriver.error.SessionNotCreatedException:
-        if not _current_session.session_id:
-            raise
+    _current_session.start()
+    await _current_session.bidi_session.start()
 
     # Enforce a fixed default window size and position
     _current_session.window.size = defaults.WINDOW_SIZE