gerrit_util: replace Optional[conn] with gerrit_host in is_applicable

This CL replaces Optional[HttpConn] with gerrit_host, which is the
actual information we need for the check.

This allows us to check without instantiating an actual request (e.g.
for best effort credential checks).

This CL has no functional change.

Bug: 348024314
Change-Id: I14d951fa9c4ebe55718fc8419190547887c0b1bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/7065051
Commit-Queue: Jiewei Qian <qjw@chromium.org>
Auto-Submit: Jiewei Qian <qjw@chromium.org>
Reviewed-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Scott Lee <ddoman@chromium.org>

gerrit_util.py

@@ -264,12 +264,12 @@ class _Authenticator(object):
         raise NotImplementedError()
 
     @classmethod
-    def is_applicable(cls, *, conn: Optional[HttpConn] = None) -> bool:
+    def is_applicable(cls, *, gerrit_host: Optional[str] = None) -> bool:
         """Must return True if this Authenticator is available in the current
         environment.
 
-        If conn is not None, return True if this Authenticator is
-        applicable to the given conn in the current environment.
+        If `gerrit_host` isn't None, it should be the hostname of a Gerrit
+        server, such as "chromium-review.googlesource.com".
         """
         raise NotImplementedError()
 
@@ -394,12 +394,12 @@ class SSOAuthenticator(_Authenticator):
         )
 
     @classmethod
-    def is_applicable(cls, *, conn: Optional[HttpConn] = None) -> bool:
+    def is_applicable(cls, *, gerrit_host: Optional[str] = None) -> bool:
         if not cls._resolve_sso_cmd():
             return False
         email: str = scm.GIT.GetConfig(os.getcwd(), 'user.email', default='')
-        if conn is not None:
-            return ShouldUseSSO(conn.host, email)
+        if gerrit_host is not None:
+            return ShouldUseSSO(gerrit_host, email)
         return email.endswith('@google.com')
 
     @classmethod
@@ -616,7 +616,7 @@ class CookiesAuthenticator(_Authenticator):
         self._gitcookies = self._EMPTY
 
     @classmethod
-    def is_applicable(cls, *, conn: Optional[HttpConn] = None) -> bool:
+    def is_applicable(cls, *, gerrit_host: Optional[str] = None) -> bool:
         # We consider CookiesAuthenticator always applicable for now.
         return True
 
@@ -775,7 +775,7 @@ class GceAuthenticator(_Authenticator):
     _token_expiration = None
 
     @classmethod
-    def is_applicable(cls, *, conn: Optional[HttpConn] = None):
+    def is_applicable(cls, *, gerrit_host: Optional[str] = None):
         if os.getenv('SKIP_GCE_AUTH_FOR_GIT'):
             return False
         if cls._cache_is_gce is None:
@@ -853,7 +853,7 @@ class LuciContextAuthenticator(_Authenticator):
     """_Authenticator implementation that uses LUCI_CONTEXT ambient local auth.
     """
     @staticmethod
-    def is_applicable(*, conn: Optional[HttpConn] = None):
+    def is_applicable(*, gerrit_host: Optional[str] = None):
         return auth.has_luci_context_local_auth()
 
     def __init__(self):
@@ -962,8 +962,8 @@ class GitCredsAuthenticator(_Authenticator):
                 "Got error trying to cache 'depot-tools.hostHasAccount': %s", e)
         return True
 
-    def is_applicable(self, *, conn: Optional[HttpConn] = None):
-        return self.gerrit_account_exists(conn.host)
+    def is_applicable(self, *, gerrit_host: Optional[str] = None):
+        return self.gerrit_account_exists(gerrit_host)
 
 
 class NoAuthenticator(_Authenticator):
@@ -971,7 +971,7 @@ class NoAuthenticator(_Authenticator):
     """
 
     @staticmethod
-    def is_applicable(*, conn: Optional[HttpConn] = None):
+    def is_applicable(*, gerrit_host: Optional[str] = None):
         return True
 
     def authenticate(self, conn: HttpConn):
@@ -990,13 +990,15 @@ class ChainedAuthenticator(_Authenticator):
     def __init__(self, authenticators: List[_Authenticator]):
         self.authenticators = list(authenticators)
 
-    def is_applicable(self, *, conn: Optional[HttpConn] = None) -> bool:
-        return bool(any(
-            a.is_applicable(conn=conn) for a in self.authenticators))
+    def is_applicable(self, *, gerrit_host: Optional[str] = None) -> bool:
+        return bool(
+            any(
+                a.is_applicable(gerrit_host=gerrit_host)
+                for a in self.authenticators))
 
     def authenticate(self, conn: HttpConn):
         for a in self.authenticators:
-            if a.is_applicable(conn=conn):
+            if a.is_applicable(gerrit_host=conn.host):
                 a.authenticate(conn)
                 break
         else:
@@ -1006,9 +1008,8 @@ class ChainedAuthenticator(_Authenticator):
     def attempt_authenticate_with_reauth(self, conn: HttpConn,
                                          context: auth.ReAuthContext) -> bool:
         for a in self.authenticators:
-            if a.is_applicable(
-                    conn=conn) and a.attempt_authenticate_with_reauth(
-                        conn, context):
+            if (a.is_applicable(gerrit_host=conn.host)
+                    and a.attempt_authenticate_with_reauth(conn, context)):
                 return True
         return False