improve loading time by only doing require when needed

lib/core/engine.js

@@ -1,19 +1,5 @@
 const async = require('async');
 
-const Events = require('./events.js');
-const Logger = require('./logger.js');
-const Config = require('./config.js');
-const Blockchain = require('../contracts/blockchain.js');
-const Compiler = require('../contracts/compiler.js');
-const ContractsManager = require('../contracts/contracts.js');
-const ContractDeployer = require('../contracts/contract_deployer.js');
-const DeployManager = require('../contracts/deploy_manager.js');
-const CodeGenerator = require('../contracts/code_generator.js');
-const ServicesMonitor = require('./services_monitor.js');
-const Pipeline = require('../pipeline/pipeline.js');
-const Watch = require('../pipeline/watch.js');
-const LibraryManager = require('../versions/library_manager.js');
-const CodeRunner = require('../coderunner/codeRunner.js');
 const utils = require('../utils/utils');
 
 class Engine {
@@ -32,6 +18,10 @@ class Engine {
   }
 
   init(_options) {
+    const Events = require('./events.js');
+    const Logger = require('./logger.js');
+    const Config = require('./config.js');
+
     let options = _options || {};
     this.events = options.events || this.events || new Events();
     this.logger = options.logger || new Logger({logLevel: options.logLevel || this.logLevel || 'debug', events: this.events, logFile: this.logFile});
@@ -105,6 +95,7 @@ class Engine {
   pipelineService(_options) {
     const self = this;
     this.events.emit("status", "Building Assets");
+    const Pipeline = require('../pipeline/pipeline.js');
     const pipeline = new Pipeline({
       buildDir: this.config.buildDir,
       contractsFiles: this.config.contractsFiles,
@@ -127,6 +118,7 @@ class Engine {
 
   serviceMonitor() {
     const self = this;
+    const ServicesMonitor = require('./services_monitor.js');
     this.servicesMonitor = new ServicesMonitor({events: this.events, logger: this.logger, plugins: this.plugins});
     this.servicesMonitor.addCheck('embarkVersion', function (cb) {
       return cb({name: 'Embark ' + self.version, status: 'on'});
@@ -139,6 +131,7 @@ class Engine {
   }
 
   codeRunnerService(_options) {
+    const CodeRunner = require('../coderunner/codeRunner.js');
     this.codeRunner = new CodeRunner({
       plugins: this.plugins,
       events: this.events,
@@ -149,6 +142,7 @@ class Engine {
   codeGeneratorService(_options) {
     let self = this;
 
+    const CodeGenerator = require('../contracts/code_generator.js');
     this.codeGenerator = new CodeGenerator({
       blockchainConfig: self.config.blockchainConfig,
       contractsConfig: self.config.contractsConfig,
@@ -182,6 +176,7 @@ class Engine {
   deploymentService(options) {
     let self = this;
 
+    const Compiler = require('../contracts/compiler.js');
     let compiler = new Compiler({plugins: self.plugins, logger: self.logger});
     this.events.setCommandHandler("compiler:contracts", function(contractFiles, cb) {
       compiler.compile_contracts(contractFiles, cb);
@@ -193,6 +188,7 @@ class Engine {
     this.registerModule('deploytracker');
     this.registerModule('specialconfigs');
 
+    const ContractsManager = require('../contracts/contracts.js');
     this.contractsManager = new ContractsManager({
       contractFiles: this.config.contractsFiles,
       contractsConfig: this.config.contractsConfig,
@@ -202,6 +198,7 @@ class Engine {
       events: this.events
     });
 
+    const DeployManager = require('../contracts/deploy_manager.js');
     this.deployManager = new DeployManager({
       blockchain: this.blockchain,
       config: this.config,
@@ -211,6 +208,7 @@ class Engine {
       onlyCompile: options.onlyCompile
     });
 
+    const ContractDeployer = require('../contracts/contract_deployer.js');
     this.contractDeployer = new ContractDeployer({
       blockchain: this.blockchain,
       logger: this.logger,
@@ -240,6 +238,7 @@ class Engine {
 
   fileWatchService(_options) {
     this.events.emit("status", "Watching for changes");
+    const Watch = require('../pipeline/watch.js');
     this.watch = new Watch({logger: this.logger, events: this.events});
     this.watch.start();
   }
@@ -264,6 +263,7 @@ class Engine {
   }
 
   web3Service(options) {
+    const Blockchain = require('../contracts/blockchain.js');
     this.blockchain = new Blockchain({
       contractsConfig: this.config.contractsConfig,
       blockchainConfig: this.config.blockchainConfig,
@@ -282,6 +282,7 @@ class Engine {
   }
 
   libraryManagerService(_options) {
+    const LibraryManager = require('../versions/library_manager.js');
     this.libraryManager = new LibraryManager({
       plugins: this.plugins,
       config: this.config

lib/index.js

@@ -12,8 +12,6 @@ process.chdir = (...args) => {
     realChdir(...args);
 };
 
-let Engine = require('./core/engine.js');
-
 let version = require('../package.json').version;
 
 class Embark {
@@ -69,6 +67,7 @@ class Embark {
     self.context = options.context || [constants.contexts.run, constants.contexts.build];
     let Dashboard = require('./dashboard/dashboard.js');
 
+    let Engine = require('./core/engine.js');
     let engine = new Engine({
       env: options.env,
       client: options.client,
@@ -159,6 +158,7 @@ class Embark {
   build(options) {
     this.context = options.context || [constants.contexts.build];
 
+    let Engine = require('./core/engine.js');
     let engine = new Engine({
       env: options.env,
       client: options.client,
@@ -214,6 +214,7 @@ class Embark {
     this.context = options.context || [constants.contexts.graph];
     options.onlyCompile = true;
     
+    let Engine = require('./core/engine.js');
     let engine = new Engine({
       env: options.env,
       isDev: this.isDev(options.env),
@@ -269,6 +270,7 @@ class Embark {
   upload(options) {
     this.context = options.context || [constants.contexts.upload, constants.contexts.build];
 
+    let Engine = require('./core/engine.js');
     let engine = new Engine({
       env: options.env,
       client: options.client,