feat: Helper functions for custom responses

Helper functions for custom responses

.editorconfig

@@ -0,0 +1,13 @@
+# Editor configuration, see http://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+max_line_length = off
+trim_trailing_whitespace = false

README.md

@@ -226,23 +226,23 @@ module.exports = function (request, response) {
 `POST.js` file for non ExpressJS server:
 
 ```js
-var fs = require('fs');
-var path = require('path');
+const fs = require('fs');
+const path = require('path');
 
-module.exports = function (request, response) {
+module.exports = (request, response) => {
   if (!request.get('X-Auth-Key')) {
     response.statusCode = 403;
     response.end();
   } else {
-    var filePath = path.join(__dirname, 'POST.json');
-    var stat = fs.statSync(filePath);
+    const filePath = path.join(__dirname, 'POST.json');
+    const stat = fs.statSync(filePath);
 
     response.writeHead(200, {
         'Content-Type': 'application/json',
         'Content-Length': stat.size
     });
 
-    var readStream = fs.createReadStream(filePath);
+    const readStream = fs.createReadStream(filePath);
     // We replaced all the event handlers with a simple call to readStream.pipe()
     readStream.pipe(response);
   }
@@ -260,7 +260,7 @@ const fs = require('fs');
 const path = require('path');
 
 module.exports = function (request, response) {
-  var targetFileName = 'GET.json';
+  let targetFileName = 'GET.json';
 
   // Check is a type parameter exist
   if (request.query.type) {
@@ -281,13 +281,13 @@ module.exports = function (request, response) {
 ```
 `GET.js` file for non ExpressJS server:
 ```js
-var url =  require('url');
-var fs = require('fs');
-var path = require('path');
+const url =  require('url');
+const fs = require('fs');
+const path = require('path');
 
 module.exports = function (request, response) {
-  var targetFileName = 'GET.json';
-  var typeQueryParam = url.parse(request.url, true).query.type;
+  let targetFileName = 'GET.json';
+  const typeQueryParam = url.parse(request.url, true).query.type;
   // Check is a type parameter exist
   if (typeQueryParam) {
     // Generate a new targetfilename with that type parameter
@@ -306,18 +306,46 @@ module.exports = function (request, response) {
     return;
   }
 
-  var stat = fs.statSync(filePath);
+  const stat = fs.statSync(filePath);
   response.writeHead(200, {
       'Content-Type': 'application/json',
       'Content-Length': stat.size
   });
 
-  var readStream = fs.createReadStream(filePath);
+  const readStream = fs.createReadStream(filePath);
   // We replaced all the event handlers with a simple call to readStream.pipe()
   readStream.pipe(response);
 }
 ```
 
+## Helper functions for custom responses
+
+Connect-Api-Mocker also presents a bunch of helper functions to speed up writing simple custom responses. There are:
+
+- `status(statusCode)`: Set status code of response
+- `notFound(message?)`: Set status code as 404 and optionally sends message
+- `created()`: Sets status code as 201
+- `success()`: Sets status code as 200
+- `delay(duration)`: Delays the request by given duration(in ms).
+- `json(data)`: Send given JSON object as response.
+- `end(body)`: Ends request and optionally sends the string output
+
+You can use these functions in custom responses, like:
+
+```js
+const { notFound } = require('connect-api-mocker/helpers');
+
+module.exports = notFound('Page is not found');
+```
+
+Also you can combine multiple functions:
+
+```js
+const { delay, created, json } = require('connect-api-mocker/helpers');
+
+module.exports = [delay(500), created(), json({success: true})];
+```
+
 ## Wildcards in requests
 
 You can use wildcards for paths to handle multiple urls(like for IDs). If you create a folder structure like `api/users/__user_id__/GET.js`, all requests like `/api/users/321` or `/api/users/1` will be responded by custom middleware that defined in your `GET.js`. Also id part of the path will be passed as a request parameter named as `user_id` to your middleware. So you can write a middleware like that:

helpers/created.js

@@ -0,0 +1,3 @@
+const status = require('./status');
+
+module.exports = () => status(201);

helpers/delay.js

@@ -0,0 +1,3 @@
+module.exports = (duration) => (req, res, next) => {
+  setTimeout(next, duration);
+};

helpers/end.js

@@ -0,0 +1,3 @@
+module.exports = message => (req, res) => {
+  res.end(message);
+};

helpers/index.js

@@ -0,0 +1,9 @@
+module.exports = {
+  delay: require('./delay'),
+  json: require('./json'),
+  status: require('./status'),
+  notFound: require('./not-found'),
+  created: require('./created'),
+  success: require('./success'),
+  end: require('./end')
+};

helpers/json.js

@@ -0,0 +1,4 @@
+module.exports = data => (req, res) => {
+  res.setHeader('content-type', 'application/json');
+  res.end(JSON.stringify(data));
+};

helpers/not-found.js

@@ -0,0 +1,4 @@
+const status = require('./status');
+const end = require('./end');
+
+module.exports = message => [status(404), end(message)];

helpers/status.js

@@ -0,0 +1,4 @@
+module.exports = status => (req, res, next) => {
+  res.statusCode = status;
+  next();
+};

helpers/success.js

@@ -0,0 +1,3 @@
+const status = require('./status');
+
+module.exports = () => status(200);

index.js

@@ -169,12 +169,20 @@ module.exports = function (urlRoot, pathRoot) {
           req, filePath, fileType: 'js', config
         });
         delete require.cache[require.resolve(path.resolve(filePath))];
-        const customMiddleware = require(path.resolve(filePath));
+        let customMiddleware = require(path.resolve(filePath));
         if (requestParams) {
           req.params = requestParams;
         }
         bodyParser.json()(req, res, () => {
-          customMiddleware(req, res, next);
+          if (typeof customMiddleware === 'function') {
+            customMiddleware = [customMiddleware];
+          }
+          // flatten middlewares
+          customMiddleware = [].concat(...customMiddleware);
+
+          customMiddleware.reduce((chain, middleware) => chain.then(
+            () => new Promise(resolve => middleware(req, res, resolve))
+          ), Promise.resolve()).then(next);
         });
       } else {
         let fileType = config.type || 'json';

test/mock-helpers.spec.js

@@ -0,0 +1,31 @@
+const request = require('supertest');
+const express = require('express');
+const apiMocker = require('..');
+
+const app = express();
+
+app.use('/api', apiMocker('test/mocks/helpers'));
+
+describe('Helpers', () => {
+  it('delay, created(status), json response', (done) => {
+    request(app)
+      .post('/api/users')
+      .expect('Content-Type', /json/)
+      .expect(201)
+      .expect({
+        success: true
+      }, done);
+  });
+
+  it('notFound', (done) => {
+    request(app)
+      .get('/api/users')
+      .expect(404, done);
+  });
+
+  it('success', (done) => {
+    request(app)
+      .patch('/api/users')
+      .expect(200, done);
+  });
+});

test/mocks/helpers/users/GET.js

@@ -0,0 +1,3 @@
+const { notFound } = require('../../../../helpers');
+
+module.exports = notFound();

test/mocks/helpers/users/PATCH.js

@@ -0,0 +1,3 @@
+const { success, end } = require('../../../../helpers');
+
+module.exports = [success(), end()];

test/mocks/helpers/users/POST.js

@@ -0,0 +1,3 @@
+const { delay, created, json } = require('../../../../helpers');
+
+module.exports = [delay(100), created(), json({ success: true })];