[py] Automate RemoteConnection subclass selection (#8010)

Select an appropriate RemoteConnection subclass based on specified
capabilities while instantiating WebDriver (aka Remote) class.

Add a new field "brower_name" to RemoteConnection class.
Field can be overridden in RemoteConnection subclasses
that wish to handle connections to specific browsers.

Related #7959

py/selenium/webdriver/chromium/remote_connection.py

@@ -16,10 +16,13 @@
 # under the License.
 
 from selenium.webdriver.remote.remote_connection import RemoteConnection
+from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
 
 
 class ChromiumRemoteConnection(RemoteConnection):
 
+    browser_name = DesiredCapabilities.CHROME['browserName']
+
     def __init__(self, remote_server_addr, keep_alive=True):
         RemoteConnection.__init__(self, remote_server_addr, keep_alive)
         self._commands["launchApp"] = ('POST', '/session/$sessionId/chromium/launch_app')

py/selenium/webdriver/firefox/remote_connection.py

@@ -16,9 +16,13 @@
 # under the License.
 
 from selenium.webdriver.remote.remote_connection import RemoteConnection
+from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
 
 
 class FirefoxRemoteConnection(RemoteConnection):
+
+    browser_name = DesiredCapabilities.FIREFOX['browserName']
+
     def __init__(self, remote_server_addr, keep_alive=True):
         RemoteConnection.__init__(self, remote_server_addr, keep_alive)
 

py/selenium/webdriver/remote/remote_connection.py

@@ -41,6 +41,7 @@ class RemoteConnection(object):
     Communicates with the server using the WebDriver wire protocol:
     https://github.com/SeleniumHQ/selenium/wiki/JsonWireProtocol"""
 
+    browser_name = None
     _timeout = socket._GLOBAL_DEFAULT_TIMEOUT
 
     @classmethod

py/selenium/webdriver/remote/webdriver.py

@@ -95,6 +95,20 @@ def _make_w3c_caps(caps):
     return {"firstMatch": [{}], "alwaysMatch": always_match}
 
 
+def get_remote_connection(capabilities, command_executor, keep_alive):
+    from selenium.webdriver.chromium.remote_connection import ChromiumRemoteConnection
+    from selenium.webdriver.safari.remote_connection import SafariRemoteConnection
+    from selenium.webdriver.firefox.remote_connection import FirefoxRemoteConnection
+
+    candidates = [RemoteConnection] + [ChromiumRemoteConnection, SafariRemoteConnection, FirefoxRemoteConnection]
+    handler = next(
+        (c for c in candidates if c.browser_name == capabilities.get('browserName')),
+        RemoteConnection
+    )
+
+    return handler(command_executor, keep_alive=keep_alive)
+
+
 class WebDriver(object):
     """
     Controls a browser by sending commands to a remote server.
@@ -143,7 +157,7 @@ def __init__(self, command_executor='http://127.0.0.1:4444',
                 capabilities.update(desired_capabilities)
         self.command_executor = command_executor
         if type(self.command_executor) is bytes or isinstance(self.command_executor, str):
-            self.command_executor = RemoteConnection(command_executor, keep_alive=keep_alive)
+            self.command_executor = get_remote_connection(capabilities, command_executor=command_executor, keep_alive=keep_alive)
         self._is_remote = True
         self.session_id = None
         self.capabilities = {}

py/selenium/webdriver/safari/remote_connection.py

@@ -16,9 +16,13 @@
 # under the License.
 
 from selenium.webdriver.remote.remote_connection import RemoteConnection
+from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
 
 
 class SafariRemoteConnection(RemoteConnection):
+
+    browser_name = DesiredCapabilities.SAFARI['browserName']
+
     def __init__(self, remote_server_addr, keep_alive=True):
         RemoteConnection.__init__(self, remote_server_addr, keep_alive)