From 2df5ecae79bc109a2a7502eef07633be48a1827e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aur=C3=A9lien=20Georget?= <aurelsicoko@gmail.com>
Date: Sat, 5 Jan 2019 18:14:00 +0100
Subject: [PATCH] Reset loaders on every request to avoid wrong results coming
 from cache

---
 .../strapi-plugin-graphql/services/Loaders.js | 22 +++++++++++++++++--
 .../strapi-plugin-graphql/services/Query.js   |  5 +++++
 .../services/Resolvers.js                     |  3 ---
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/packages/strapi-plugin-graphql/services/Loaders.js b/packages/strapi-plugin-graphql/services/Loaders.js
index 1c59ed1811..63a3b2f16f 100644
--- a/packages/strapi-plugin-graphql/services/Loaders.js
+++ b/packages/strapi-plugin-graphql/services/Loaders.js
@@ -12,8 +12,26 @@ const DataLoader = require('dataloader');
 module.exports = {
   loaders: {},
 
-  createLoader: function(model) {
-    this.loaders[model] = new DataLoader(keys => {
+  initializeLoader: function() {
+    // Create loaders for each relational field (exclude core models).
+    Object.keys(strapi.models)
+      .filter(model => model !== 'core_store')
+      .forEach(model => {
+        (strapi.models[model].associations || []).forEach(association => this.createLoader(association.collection || association.model, association.plugin));
+      });
+
+    // Reproduce the same pattern for each plugin.
+    Object.keys(strapi.plugins).forEach(plugin => {
+      Object.keys(strapi.plugins[plugin].models).forEach(model => {
+        (strapi.plugins[plugin].models[model].associations || []).forEach(association => this.createLoader(association.collection || association.model, association.plugin));
+      });
+    });
+  },
+
+  createLoader: function(model, plugin) {
+    const name = plugin ? `${plugin}__${model}`: model;
+
+    this.loaders[name] = new DataLoader(keys => {
       return new Promise(async (resolve, reject) => {
         try {
           // Extract queries from keys and merge similar queries.
diff --git a/packages/strapi-plugin-graphql/services/Query.js b/packages/strapi-plugin-graphql/services/Query.js
index f4801c243a..e096881f26 100644
--- a/packages/strapi-plugin-graphql/services/Query.js
+++ b/packages/strapi-plugin-graphql/services/Query.js
@@ -10,6 +10,8 @@ const _ = require('lodash');
 const pluralize = require('pluralize');
 const policyUtils = require('strapi-utils').policy;
 
+const Loaders = require('./Loaders');
+
 module.exports = {
   /**
    * Convert parameters to valid filters parameters.
@@ -256,6 +258,9 @@ module.exports = {
         return policy;
       }
 
+      // Initiliase loaders for this request.
+      Loaders.initializeLoader();
+
       // Resolver can be a function. Be also a native resolver or a controller's action.
       if (_.isFunction(resolver)) {
         context.query = this.convertToParams(options);
diff --git a/packages/strapi-plugin-graphql/services/Resolvers.js b/packages/strapi-plugin-graphql/services/Resolvers.js
index cd2800e4f3..849b7b9c80 100644
--- a/packages/strapi-plugin-graphql/services/Resolvers.js
+++ b/packages/strapi-plugin-graphql/services/Resolvers.js
@@ -362,9 +362,6 @@ module.exports = {
           default:
         }
 
-        // Create dynamic dataloader for query batching and caching.
-        Loaders.createLoader(association.collection || association.model, association.plugin);
-
         _.merge(acc.resolver[globalId], {
           [association.alias]: async (obj, options) => {
             // eslint-disable-line no-unused-vars