Add support for multiple domains to FILESET_LIVE_DOMAIN

Author: jeremydw

src/server.test.ts

@@ -20,6 +20,14 @@ test('Test parseHostname', (t: ExecutionContext) => {
       branchOrRef: 'master',
     }
   );
+  // Multiple live domains.
+  t.deepEqual(
+    server.parseHostname('example.com', 'example', 'example.com,foo.com'),
+    {
+      siteId: 'example',
+      branchOrRef: 'master',
+    }
+  );
   // Some other domain.
   t.deepEqual(
     server.parseHostname('something.com', 'example', 'example.com'),

src/server.ts

@@ -54,7 +54,7 @@ const getManifest = async (siteId: string, branchOrRef: string) => {
 export function parseHostname(hostname: string, defaultSiteId?: string, defaultLiveDomain?: string) {
   let siteId = defaultSiteId || 'default';
   let branchOrRef = '';
-  if (hostname == defaultLiveDomain) {
+  if (defaultLiveDomain && defaultLiveDomain.split(',').includes(hostname)) {
     // Hostname is the "live" or "prod" domain. Use the master branch.
     branchOrRef = 'master';
   } else if (hostname.includes('-dot-')) {