minor: throw exception if refresh_token is not present

frappe/email/oauth.py

@@ -32,14 +32,21 @@ class Oauth:
 		self._access_token = access_token
 		self._refresh_token = refresh_token
 
-		self.validate_implementation()
+		self.validate()
 
-	def validate_implementation(self) -> None:
+	def validate(self) -> None:
 		if self.service != "GMail":
 			raise NotImplementedError(
 				f"Service {self.service} currently doesn't have oauth implementation."
 			)
 
+		if not self._refresh_token:
+			frappe.throw(
+				frappe._("Please Authorize OAuth."),
+				OAuthenticationError,
+				frappe._("OAuth Error"),
+			)
+
 	@property
 	def _auth_string(self) -> str:
 		return "user=%s\1auth=Bearer %s\1\1" % (self.email, self._access_token)

frappe/email/receive.py

@@ -100,7 +100,7 @@ class EmailServer:
 					self.settings.host, self.settings.incoming_port, timeout=frappe.conf.get("pop_timeout")
 				)
 
-			if self.settings.use_oauth and self.settings.refresh_token:
+			if self.settings.use_oauth:
 				Oauth(
 					self.imap,
 					self.settings.email_account,
@@ -133,7 +133,7 @@ class EmailServer:
 					self.settings.host, self.settings.incoming_port, timeout=frappe.conf.get("pop_timeout")
 				)
 
-			if self.settings.use_oauth and self.settings.refresh_token:
+			if self.settings.use_oauth:
 				Oauth(
 					self.pop,
 					self.settings.email_account,

frappe/email/smtp.py

@@ -111,7 +111,7 @@ class SMTPServer:
 
 			self.secure_session(_session)
 
-			if self.use_oauth and self.refresh_token:
+			if self.use_oauth:
 				Oauth(
 					_session, self.email_account, self.login, self.access_token, self.refresh_token, self.service
 				).connect()