Add pagination mongoose plugin

closes #13
hagopj13 · May 17, 2020 · 97fef4c · 97fef4c
1 parent c6c4206
commit 97fef4c
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Showing 10 changed files with 165 additions and 83 deletions.
diff --git a/src/controllers/user.controller.js b/src/controllers/user.controller.js
@@ -3,17 +3,16 @@ const { pick } = require('lodash');
 const ApiError = require('../utils/ApiError');
 const catchAsync = require('../utils/catchAsync');
 const { userService } = require('../services');
-const { getQueryOptions } = require('../utils/query.utils');
 
 const createUser = catchAsync(async (req, res) => {
   const user = await userService.createUser(req.body);
   res.status(httpStatus.CREATED).send(user);
 });
 
 const getUsers = catchAsync(async (req, res) => {
-  const filter = pick(req.query, ['name', 'role']);
-  const options = getQueryOptions(req.query);
-  const users = await userService.getUsers(filter, options);
+  const query = pick(req.query, ['name', 'role']);
+  const options = pick(req.query, ['sortBy', 'limit', 'page']);
+  const users = await userService.queryUsers(query, options);
   res.send(users);
 });
 

diff --git a/src/models/plugins.js b/src/models/plugins.js
@@ -0,0 +1,66 @@
+/* eslint-disable no-param-reassign */
+
+/**
+ * A mongoose schema plugin which applies the following in the toJSON transform call:
+ *  - removes __v, createdAt, updatedAt, and any path that has private: true
+ *  - replaces _id with id
+ */
+const toJSON = (schema) => {
+  let transform;
+  if (schema.options.toJSON && schema.options.toJSON.transform) {
+    transform = schema.options.toJSON.transform;
+  }
+
+  schema.options.toJSON = Object.assign(schema.options.toJSON || {}, {
+    transform(doc, ret, options) {
+      Object.keys(schema.paths).forEach((path) => {
+        if (schema.paths[path].options && schema.paths[path].options.private) {
+          delete ret[path];
+        }
+      });
+
+      ret.id = ret._id.toString();
+      delete ret._id;
+      delete ret.__v;
+      delete ret.createdAt;
+      delete ret.updatedAt;
+      if (transform) {
+        return transform(doc, ret, options);
+      }
+    },
+  });
+};
+
+const paginate = (schema) => {
+  schema.statics.paginate = async function (query, options) {
+    const sort = {};
+    if (options.sortBy) {
+      const parts = options.sortBy.split(':');
+      sort[parts[0]] = parts[1] === 'desc' ? -1 : 1;
+    }
+    const limit = options.limit && parseInt(options.limit, 10) > 0 ? parseInt(options.limit, 10) : 10;
+    const page = options.page && parseInt(options.page, 10) > 0 ? parseInt(options.page, 10) : 1;
+    const skip = (page - 1) * limit;
+
+    const countPromise = this.countDocuments(query).exec();
+    const docsPromise = this.find(query).sort(sort).skip(skip).limit(limit).exec();
+
+    return Promise.all([countPromise, docsPromise]).then((values) => {
+      const [totalResults, results] = values;
+      const totalPages = Math.ceil(totalResults / limit);
+      const result = {
+        results,
+        page,
+        limit,
+        totalPages,
+        totalResults,
+      };
+      return Promise.resolve(result);
+    });
+  };
+};
+
+module.exports = {
+  toJSON,
+  paginate,
+};
diff --git a/src/models/token.model.js b/src/models/token.model.js
@@ -1,5 +1,5 @@
 const mongoose = require('mongoose');
-const { toJSON } = require('./utils');
+const { toJSON } = require('./plugins');
 
 const tokenSchema = mongoose.Schema(
   {

diff --git a/src/models/user.model.js b/src/models/user.model.js
@@ -1,7 +1,7 @@
 const mongoose = require('mongoose');
 const validator = require('validator');
 const bcrypt = require('bcryptjs');
-const { toJSON } = require('./utils');
+const { toJSON, paginate } = require('./plugins');
 const { roles } = require('../config/roles');
 
 const userSchema = mongoose.Schema(
@@ -48,6 +48,7 @@ const userSchema = mongoose.Schema(
 
 // add plugin that converts mongoose to json
 userSchema.plugin(toJSON);
+userSchema.plugin(paginate);
 
 userSchema.statics.isEmailTaken = async function (email, excludeUserId) {
   const user = await this.findOne({ email, _id: { $ne: excludeUserId } });

diff --git a/src/models/utils.js b/src/models/utils.js
diff --git a/src/routes/v1/user.route.js b/src/routes/v1/user.route.js
@@ -108,7 +108,7 @@ module.exports = router;
  *          schema:
  *            type: integer
  *            minimum: 1
- *          default: 100
+ *          default: 10
  *          description: Maximum number of users
  *        - in: query
  *          name: page
@@ -123,9 +123,24 @@ module.exports = router;
  *          content:
  *            application/json:
  *              schema:
- *                type: array
- *                items:
- *                  $ref: '#/components/schemas/User'
+ *                type: object
+ *                properties:
+ *                  results:
+ *                    type: array
+ *                    items:
+ *                      $ref: '#/components/schemas/User'
+ *                  page:
+ *                    type: integer
+ *                    example: 1
+ *                  limit:
+ *                    type: integer
+ *                    example: 10
+ *                  totalPages:
+ *                    type: integer
+ *                    example: 1
+ *                  totalResults:
+ *                    type: integer
+ *                    example: 1
  *        "401":
  *          $ref: '#/components/responses/Unauthorized'
  *        "403":

diff --git a/src/services/user.service.js b/src/services/user.service.js
@@ -10,8 +10,8 @@ const createUser = async (userBody) => {
   return user;
 };
 
-const getUsers = async (filter, options) => {
-  const users = await User.find(filter, null, options);
+const queryUsers = async (query, options) => {
+  const users = await User.paginate(query, options);
   return users;
 };
 
@@ -47,7 +47,7 @@ const deleteUserById = async (userId) => {
 
 module.exports = {
   createUser,
-  getUsers,
+  queryUsers,
   getUserById,
   getUserByEmail,
   updateUserById,

diff --git a/src/utils/query.utils.js b/src/utils/query.utils.js
diff --git a/tests/integration/user.test.js b/tests/integration/user.test.js
@@ -135,7 +135,7 @@ describe('User routes', () => {
   });
 
   describe('GET /v1/users', () => {
-    test('should return 200 and all users', async () => {
+    test('should return 200 and apply the default query options', async () => {
       await insertUsers([userOne, userTwo, admin]);
 
       const res = await request(app)
@@ -144,9 +144,15 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toBeInstanceOf(Array);
-      expect(res.body).toHaveLength(3);
-      expect(res.body[0]).toEqual({
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 1,
+        limit: 10,
+        totalPages: 1,
+        totalResults: 3,
+      });
+      expect(res.body.results).toHaveLength(3);
+      expect(res.body.results[0]).toEqual({
         id: userOne._id.toHexString(),
         name: userOne.name,
         email: userOne.email,
@@ -180,8 +186,15 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toHaveLength(1);
-      expect(res.body[0].id).toBe(userOne._id.toHexString());
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 1,
+        limit: 10,
+        totalPages: 1,
+        totalResults: 1,
+      });
+      expect(res.body.results).toHaveLength(1);
+      expect(res.body.results[0].id).toBe(userOne._id.toHexString());
     });
 
     test('should correctly apply filter on role field', async () => {
@@ -194,9 +207,16 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toHaveLength(2);
-      expect(res.body[0].id).toBe(userOne._id.toHexString());
-      expect(res.body[1].id).toBe(userTwo._id.toHexString());
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 1,
+        limit: 10,
+        totalPages: 1,
+        totalResults: 2,
+      });
+      expect(res.body.results).toHaveLength(2);
+      expect(res.body.results[0].id).toBe(userOne._id.toHexString());
+      expect(res.body.results[1].id).toBe(userTwo._id.toHexString());
     });
 
     test('should correctly sort returned array if descending sort param is specified', async () => {
@@ -209,8 +229,17 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toHaveLength(3);
-      expect(res.body[0].id).toBe(userOne._id.toHexString());
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 1,
+        limit: 10,
+        totalPages: 1,
+        totalResults: 3,
+      });
+      expect(res.body.results).toHaveLength(3);
+      expect(res.body.results[0].id).toBe(userOne._id.toHexString());
+      expect(res.body.results[1].id).toBe(userTwo._id.toHexString());
+      expect(res.body.results[2].id).toBe(admin._id.toHexString());
     });
 
     test('should correctly sort returned array if ascending sort param is specified', async () => {
@@ -223,8 +252,17 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toHaveLength(3);
-      expect(res.body[0].id).toBe(admin._id.toHexString());
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 1,
+        limit: 10,
+        totalPages: 1,
+        totalResults: 3,
+      });
+      expect(res.body.results).toHaveLength(3);
+      expect(res.body.results[0].id).toBe(admin._id.toHexString());
+      expect(res.body.results[1].id).toBe(userOne._id.toHexString());
+      expect(res.body.results[2].id).toBe(userTwo._id.toHexString());
     });
 
     test('should limit returned array if limit param is specified', async () => {
@@ -237,7 +275,16 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toHaveLength(2);
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 1,
+        limit: 2,
+        totalPages: 2,
+        totalResults: 3,
+      });
+      expect(res.body.results).toHaveLength(2);
+      expect(res.body.results[0].id).toBe(userOne._id.toHexString());
+      expect(res.body.results[1].id).toBe(userTwo._id.toHexString());
     });
 
     test('should return the correct page if page and limit params are specified', async () => {
@@ -250,8 +297,15 @@ describe('User routes', () => {
         .send()
         .expect(httpStatus.OK);
 
-      expect(res.body).toHaveLength(1);
-      expect(res.body[0].id).toBe(admin._id.toHexString());
+      expect(res.body).toEqual({
+        results: expect.any(Array),
+        page: 2,
+        limit: 2,
+        totalPages: 2,
+        totalResults: 3,
+      });
+      expect(res.body.results).toHaveLength(1);
+      expect(res.body.results[0].id).toBe(admin._id.toHexString());
     });
   });
 

diff --git a/tests/unit/models/utils.test.js → tests/unit/models/plugins.test.js b/tests/unit/models/utils.test.js → tests/unit/models/plugins.test.js
@@ -1,5 +1,5 @@
 const mongoose = require('mongoose');
-const { toJSON } = require('../../../src/models/utils');
+const { toJSON } = require('../../../src/models/plugins');
 
 describe('Model utils', () => {
   describe('toJSON plugin', () => {