Add frontend UsersCache class (!11404)

1 files changed, 28 insertions, 0 deletions

diff --git a/app/assets/javascripts/lib/utils/users_cache.js b/app/assets/javascripts/lib/utils/users_cache.js
new file mode 100644
index 00000000000..88f8a622c00
--- /dev/null
+++ b/app/assets/javascripts/lib/utils/users_cache.js
@@ -0,0 +1,28 @@
+import Api from '../../api';
+import Cache from './cache';
+
+class UsersCache extends Cache {
+  retrieve(username) {
+    if (this.hasData(username)) {
+      return Promise.resolve(this.get(username));
+    }
+
+    return Api.users('', { username })
+      .then((users) => {
+        if (!users.length) {
+          throw new Error(`User "${username}" could not be found!`);
+        }
+
+        if (users.length > 1) {
+          throw new Error(`Expected username "${username}" to be unique!`);
+        }
+
+        const user = users[0];
+        this.internalStorage[username] = user;
+        return user;
+      });
+      // missing catch is intentional, error handling depends on use case
+  }
+}
+
+export default new UsersCache();