WIP Group contributions by URL

app/utils/contribution-grouping-key.js

@@ -0,0 +1,17 @@
+import { isEmpty } from '@ember/utils';
+
+//
+// Derives a stable grouping key for a contribution, so that contributions
+// created for the same issue/pull request (one per contributor) can be
+// linked together in the UI.
+//
+// The bot writes the exact same `url` string (the html_url of the issue/PR)
+// into every per-contributor IPFS document for a given piece of work, so the
+// top-level `url` field on the model is sufficient as a grouping key. Manual
+// contributions without a URL return null and are treated as singletons.
+//
+export default function contributionGroupingKey (contribution) {
+  let url = contribution ? contribution.url : null;
+  if (isEmpty(url)) return null;
+  return url;
+}