Accept ordered doc and file updates

Add an `updates` parameter to the project update endpoint. It can be
used instead of `docUpdates` and `fileUpdates` to provide a single list
of updates in the order they should be processed.

services/document-updater/app/js/HttpController.js

@@ -330,19 +330,23 @@ function updateProject(req, res, next) {
     userId,
     docUpdates,
     fileUpdates,
+    updates,
     version
   } = req.body
   logger.log(
-    { projectId, docUpdates, fileUpdates, version },
+    { projectId, updates, docUpdates, fileUpdates, version },
     'updating project via http'
   )
-
+  const allUpdates = _mergeUpdates(
+    docUpdates || [],
+    fileUpdates || [],
+    updates || []
+  )
   ProjectManager.updateProjectWithLocks(
     projectId,
     projectHistoryId,
     userId,
-    docUpdates,
-    fileUpdates,
+    allUpdates,
     version,
     (error) => {
       timer.done()
@@ -412,3 +416,23 @@ function flushQueuedProjects(req, res, next) {
     }
   })
 }
+
+/**
+ * Merge updates from the previous project update interface (docUpdates +
+ * fileUpdates) and the new update interface (updates).
+ */
+function _mergeUpdates(docUpdates, fileUpdates, updates) {
+  const mergedUpdates = []
+  for (const update of docUpdates) {
+    const type = update.docLines != null ? 'add-doc' : 'rename-doc'
+    mergedUpdates.push({ type, ...update })
+  }
+  for (const update of fileUpdates) {
+    const type = update.url != null ? 'add-file' : 'rename-file'
+    mergedUpdates.push({ type, ...update })
+  }
+  for (const update of updates) {
+    mergedUpdates.push(update)
+  }
+  return mergedUpdates
+}