fix(settings): prevent categorization crash when hostname not yet resolved (#759)

* fix(settings): prevent categorization crash when hostname not yet resolved

The CategoryBuilder's fetchWords() could run before the hostname was
resolved (race condition with QueryOptions component), causing it to
construct invalid bucket IDs like 'aw-watcher-window_undefined' and
display "Unable to find bucket matching" errors.

Fix: bail out of fetchWords() if no valid hostname is available yet.
The queryOptions watcher will re-trigger fetchWords() once QueryOptions
emits a valid hostname, so the data loads correctly without errors.

Fixes ActivityWatch/activitywatch#1182

* fix(settings): reset loading state on early return when hostname unavailable

Author: TimeToBuildBob

src/views/settings/CategoryBuilder.vue

@@ -191,13 +191,17 @@ export default {
     async fetchWords() {
       this.loading = true;
       if (!this.queryOptions.hostname) {
-        // FIXME: This is a hack to ensure that the hostname is set (otherwise isn't due to some race condition)
+        // Try to resolve hostname from loaded buckets
         // Don't ever return the "unknown" hostname
-        // TODO: ideally, only choose a hostname that has the right buckets
-        this.queryOptions.hostname = _.filter(
-          useBucketsStore().hosts,
-          host => host !== 'unknown'
-        )[0];
+        const hosts = useBucketsStore().hosts;
+        if (hosts && hosts.length > 0) {
+          this.queryOptions.hostname = _.filter(hosts, host => host !== 'unknown')[0];
+        }
+        // If still no valid hostname, bail out and wait for QueryOptions to provide one
+        if (!this.queryOptions.hostname) {
+          this.loading = false;
+          return;
+        }
       }
       await this.categoryStore.load();
       const awclient = getClient();