fix(deleteStatement): Recounts on single statement deletion

Transfer the logic of recounts on single statement deletion from
express-restify-mongoose to a post remove hook.

Closes LL-322

api/src/routes/HttpRoutes.js

@@ -58,8 +58,6 @@ import personaRESTHandler from 'api/routes/personas/personaRESTHandler';
 import personaIdentifierRESTHandler from 'api/routes/personas/personaIdentifierRESTHandler';
 import UserOrganisationsRouter from 'api/routes/userOrganisations/router';
 import UserOrganisationSettingsRouter from 'api/routes/userOrganisationSettings/router';
-import getLrsFromAuthInfo from 'lib/services/auth/authInfoSelectors/getLrsFromAuthInfo';
-import { decrementStatementCount } from 'lib/services/lrs';
 
 // CONSTANTS
 import * as routes from 'lib/constants/routes';
@@ -359,18 +357,8 @@ restify.serve(router, Statement, {
       return res.send('No ID sent', 400);
     }
     next();
-    return;
   },
   preUpdate: (req, res) => res.sendStatus(405),
-  postDelete: (req, _, next) => {
-    // Update LRS.statementCount
-    const authInfo = getAuthFromRequest(req);
-    const lrsId = getLrsFromAuthInfo(authInfo);
-
-    decrementStatementCount(lrsId)
-      .then(() => next())
-      .catch(err => next(err));
-  },
 });
 restify.serve(router, StatementForwarding);
 restify.serve(router, QueryBuilderCache);

lib/models/lrs.js

@@ -58,10 +58,10 @@ schema.statics.updateStatementCount = async (lrs) => {
   });
 };
 
-schema.statics.decrementStatementCount = async (lrs) => {
+schema.statics.decrementStatementCount = async (lrsId) => {
   getConnection()
     .model('Lrs')
-    .update({ _id: lrs._id }, { $inc: { statementCount: -1 } })
+    .update({ _id: lrsId }, { $inc: { statementCount: -1 } })
     .exec();
 };
 

lib/models/statement.js

@@ -23,6 +23,7 @@ import getScopeFilter from 'lib/services/auth/filters/getScopeFilter';
 import filterByOrg from 'lib/models/plugins/filterByOrg';
 import decodeDot from 'lib/helpers/decodeDot';
 import logger from 'lib/logger';
+import Lrs from 'lib/models/lrs';
 
 const ALLOW_AGGREGATION_DISK_USE = boolean(defaultTo(process.env.ALLOW_AGGREGATION_DISK_USE, true));
 const AGGREGATION_CACHE_SECONDS = defaultTo(Number(process.env.AGGREGATION_CACHE_SECONDS), 300);
@@ -94,6 +95,11 @@ schema.plugin(scopeChecks);
 schema.plugin(filterByOrg);
 schema.plugin(addCRUDFunctions);
 
+schema.post('remove', async (statement, next) => {
+  await Lrs.decrementStatementCount(statement.lrs_id);
+  next();
+});
+
 /**
  * @param {*} - {
  *                pipeline