Start of simple plugin system

Author: mitchmac

src/index.js

@@ -15,6 +15,8 @@ const phpPath = path.resolve(__dirname, '../php-files/php');
 const phpIniPath = path.resolve(__dirname, '../php-files/php.ini');
 const cwd = path.resolve(__dirname, '../php-files');
 
+const plugins = require('./plugins');
+
 async function handler(data) {
     await validate(data);
 
@@ -98,7 +100,6 @@ async function handler(data) {
             urlPath = event.rawPath;
         }
 
-
         let requestHeaders;
         if (event.cookies) {
             let cookielist = '';
@@ -176,7 +177,6 @@ async function handler(data) {
           }
         }
 
-
         if (!headers['cache-control'] && response.status === 200 && (!data.hasOwnProperty('skipCacheControl') || (data.hasOwnProperty('skipCacheControl') && !data.skipCacheControl))) {
             let cacheControl = 'max-age=3600, s-maxage=86400';
 
@@ -237,7 +237,6 @@ async function validate(data) {
         throw new Error("The event property cannot be empty.");
     }
 
-
     if (!data.hasOwnProperty("docRoot")) {
         throw new Error("The docRoot or routerScript property is required.");
     }
@@ -265,4 +264,6 @@ async function exists(path) {
 }
 
 module.exports = handler;
-module.exports.validate = validate;
+module.exports.validate = validate;
+module.exports.registerPlugin = plugins.register;
+module.exports.getPlugins = plugins.getPlugins;

src/plugins.js

@@ -0,0 +1,32 @@
+let plugins = [];
+
+function register(plugin) {
+    //@TODO: validate the plugin
+    plugins.push(plugin);
+}
+
+function getPlugins() {
+    return plugins;
+}
+
+async function executePreRequest(event) {
+    let response = null;
+    //@TODO: only loop through plugins with preRequest.
+    //@TODO: allow multiple reponses, currently last one wins.
+    for (let i = 0; i < plugins.length; i++) {
+        let plugin = plugins[i];
+        if (plugin.preRequest) {
+            response = await plugin.preRequest(event);
+        }
+    }
+
+    return response;
+}
+
+async function executePostRequest() {
+
+}
+
+module.exports.register = register;
+module.exports.getPlugins = getPlugins;
+module.exports.executePreRequest = executePreRequest;

tests/index.test.js

@@ -5,7 +5,6 @@ test('Error with missing event property', () => {
   expect(async () => await serverlesswp.validate(args)).rejects.toThrow();
 });
 
-
 test('Error with empty event property', () => {
   const args = {event: '', docRoot: '/'}
   expect(async () => await serverlesswp.validate(args)).rejects.toThrow();
@@ -24,4 +23,12 @@ test('Error with invalid docRoot property', () => {
 test('Error with invalid routerScript property', () => {
   const args = {event: {}, docRoot: '/', routerScript: '/invalid'}
   expect(async () => await serverlesswp.validate(args)).rejects.toThrow();
+});
+
+test('Plugin registration', () => {
+  serverlesswp.registerPlugin({name: 'foo'});
+  serverlesswp.registerPlugin({name: 'bar'});
+
+  const plugins = serverlesswp.getPlugins();
+  expect(plugins).toHaveLength(2);
 });

tests/plugins.test.js

@@ -0,0 +1,35 @@
+const plugins = require('../src/plugins');
+
+test('Plugin registration', () => {
+    plugins.register({name: 'foo'});
+    plugins.register({name: 'bar'});
+  
+    const pluginList = plugins.getPlugins();
+    expect(pluginList).toHaveLength(2);
+});
+
+test('Do not execute non-existent preRequest', async () => {
+    plugins.register({name: 'Test'});
+
+    const response = await plugins.executePreRequest({test: 'test'});
+    expect(response).toBeNull();
+});
+
+test('Execute preRequest', async () => {
+    const statusCode = 200;
+    const body = 'foo';
+
+    plugins.register({
+        name: 'Hello World',
+        preRequest: async function(event) {
+            return {
+                statusCode: 200,
+                body: event.test,
+            }
+        },
+    });
+
+    const response = await plugins.executePreRequest({test: body});
+    expect(response.body).toEqual(body);
+    expect(response.statusCode).toEqual(statusCode);
+});