[FIX] OAuth Login not working on Firefox (#20722)

Co-authored-by: Guilherme Gazzo <guilhermegazzo@gmail.com>

app/custom-oauth/client/custom_oauth_client.js

@@ -5,6 +5,7 @@ import { Random } from 'meteor/random';
 import { ServiceConfiguration } from 'meteor/service-configuration';
 import { OAuth } from 'meteor/oauth';
 import s from 'underscore.string';
+import './swapSessionStorage';
 
 import { isURL } from '../../utils/lib/isURL';
 

app/custom-oauth/client/swapSessionStorage.js

@@ -0,0 +1,42 @@
+import { Meteor } from 'meteor/meteor';
+import { OAuth } from 'meteor/oauth';
+import { Reload } from 'meteor/reload';
+
+// TODO: This is a nasty workaround and should be removed as soon as possible
+// Firefox is losing the sessionStorage data (v >= 79.0) after the redirect
+
+if (navigator.userAgent.indexOf('Firefox') !== -1) {
+	const KEY_NAME = 'Swapped_Storage_Workaround';
+
+	OAuth.saveDataForRedirect = (loginService, credentialToken) => {
+		Meteor._localStorage.setItem(KEY_NAME, JSON.stringify({ loginService, credentialToken }));
+		Reload._migrate(null, { immediateMigration: true });
+	};
+
+	OAuth.getDataAfterRedirect = () => {
+		let migrationData = Meteor._localStorage.getItem(KEY_NAME);
+		Meteor._localStorage.removeItem(KEY_NAME);
+		try {
+			migrationData = JSON.parse(migrationData);
+		} catch (error) {
+			migrationData = null;
+		}
+
+		if (! (migrationData && migrationData.credentialToken)) { return null; }
+
+		const { credentialToken } = migrationData;
+		const key = OAuth._storageTokenPrefix + credentialToken;
+		let credentialSecret;
+		try {
+			credentialSecret = sessionStorage.getItem(key);
+			sessionStorage.removeItem(key);
+		} catch (e) {
+			Meteor._debug('error retrieving credentialSecret', e);
+		}
+		return {
+			loginService: migrationData.loginService,
+			credentialToken,
+			credentialSecret,
+		};
+	};
+}