adds avatars constants module

wherehows-web/app/constants/avatars/avatars.ts

@@ -0,0 +1,33 @@
+import { IAvatar } from 'wherehows-web/typings/app/avatars';
+import { avatar } from 'wherehows-web/constants/application';
+import { pick } from 'lodash';
+
+/**
+ * Defines a partial interface for an object that can be narrowed into an avatar
+ */
+type PartAvatar = Partial<IAvatar>;
+
+const { url: avatarUrl } = avatar;
+
+/**
+ * Default image url if an avatar url cannot be determined
+ * @type {string}
+ */
+const defaultAvatarImage = '/assets/assets/images/default_avatar.png';
+
+/**
+ * Takes a PartAvatar object and build an object confirming to an IAvatar
+ * @param {PartAvatar} object
+ * @return {IAvatar}
+ */
+const getAvatarProps = (object: PartAvatar): IAvatar => {
+  const props = pick(object, ['email', 'userName', 'name']);
+  const imageUrl = props.userName ? avatarUrl.replace('[username]', props.userName) : defaultAvatarImage;
+
+  return {
+    imageUrl,
+    ...props
+  };
+};
+
+export { getAvatarProps };