fix(dataexport) - 12482 - Extract xml marshalling into library

- Add integration test on dataexport endpoint
- Add library with unit test for xml marshalling

website/server/libs/xmlMarshaller.js

@@ -0,0 +1,32 @@
+import _ from 'lodash';
+import * as js2xml from 'js2xmlparser';
+
+export function marshallUserData (userData) {
+  // object maps can't be marshalled to XML
+  userData.inbox.messages = _(userData.inbox.messages)
+    .map(m => {
+      m.flags = Object.keys(m.flags);
+      return m;
+    })
+    .value();
+
+  userData.newMessages = _.map(userData.newMessages, (msg, id) => ({ id, ...msg }));
+
+  // _id gets parsed as a bytearray => which gets cast to a chararray => "weird chars"
+  userData.unpinnedItems = userData.unpinnedItems.map(i => ({
+    path: i.path,
+    type: i.type,
+  }));
+
+  userData.pinnedItems = userData.pinnedItems.map(i => ({
+    path: i.path,
+    type: i.type,
+  }));
+
+  return js2xml.parse('user', userData, {
+    cdataInvalidChars: true,
+    declaration: {
+      include: false,
+    },
+  });
+}