introduced count adjusters for deleting a user

bin/cli-users

@@ -8,6 +8,7 @@ const util = require('./util');
 const program = require('commander');
 const inquirer = require('inquirer');
 const { graphql } = require('graphql');
+const helpers = require('../services/migration/helpers');
 const { stripIndent } = require('common-tags');
 const Table = require('cli-table');
 
@@ -32,6 +33,19 @@ const mongoose = require('../services/mongoose');
 // Register the shutdown criteria.
 util.onshutdown([() => mongoose.disconnect()]);
 
+/**
+ * transforms a specific action to a removal action on the target model.
+ */
+const actionDecrTransformer = ({ item_id, action_type, group_id }) => ({
+  query: { id: item_id },
+  update: {
+    $inc: {
+      [`action_counts.${action_type.toLowerCase()}`]: -1,
+      [`action_counts.${action_type.toLowerCase()}_${group_id.toLowerCase()}`]: -1,
+    },
+  },
+});
+
 /**
  * Deletes a user and cleans up their associated verifications.
  */
@@ -62,9 +76,26 @@ async function deleteUser(userID) {
       return util.shutdown();
     }
 
+    const { transformSingleWithCursor } = helpers({
+      queryBatchSize: 10000,
+      updateBatchSize: 10000,
+    });
+
     console.warn("Removing user's actions");
 
-    // FIXME: fix the counts.
+    // Remove all actions against comments.
+    await transformSingleWithCursor(
+      ActionModel.collection.find({ user_id: user.id, item_type: 'COMMENTS' }),
+      actionDecrTransformer,
+      CommentModel
+    );
+
+    // Remove all actions against users.
+    await transformSingleWithCursor(
+      ActionModel.collection.find({ user_id: user.id, item_type: 'USERS' }),
+      actionDecrTransformer,
+      UserModel
+    );
 
     // Remove all the user's actions.
     await ActionModel.where({ user_id: user.id })
@@ -73,6 +104,29 @@ async function deleteUser(userID) {
 
     console.warn("Removing user's comments");
 
+    // Removes all the user's reply counts on each of the comments that they
+    // have commented on.
+    await transformSingleWithCursor(
+      CommentModel.collection.aggregate([
+        { $match: { author_id: user.id } },
+        {
+          $group: {
+            _id: '$parent_id',
+            count: { $sum: 1 },
+          },
+        },
+      ]),
+      ({ _id: parent_id, count }) => ({
+        query: { id: parent_id },
+        update: {
+          $inc: {
+            reply_count: -1 * count,
+          },
+        },
+      }),
+      CommentModel
+    );
+
     // Remove all the user's comments.
     await CommentModel.where({ author_id: user.id })
       .setOptions({ multi: true })