Allow an ordered list of app files to be loaded in sandbox

This PR is to address a usecase where an app may want to load other assets after the vendor asset is loaded and before the app asset is loaded in the sandbox. Primarily for example, if we want to load i18n translations file, lazy engine assets. Making the appFiles an array allows other addons that will run after ember-cli-fastboot to update package.json with the order.

Author: kratiahuja

src/ember-app.js

@@ -32,8 +32,8 @@ class EmberApp {
     let distPath = path.resolve(options.distPath);
     let config = this.readPackageJSON(distPath);
 
-    this.appFilePath = config.appFile;
-    this.vendorFilePath = config.vendorFile;
+    this.appFilePaths = config.appFiles;
+    this.vendorFilePaths = config.vendorFiles;
     this.moduleWhitelist = config.moduleWhitelist;
     this.hostWhitelist = config.hostWhitelist;
     this.appConfig = config.appConfig;
@@ -128,21 +128,26 @@ class EmberApp {
   */
   loadAppFiles() {
     let sandbox = this.sandbox;
-    let appFilePath = this.appFilePath;
-    let vendorFilePath = this.vendorFilePath;
+    let appFilePaths = this.appFilePaths;
+    let vendorFilePaths = this.vendorFilePaths;
 
     sandbox.eval('sourceMapSupport.install(Error);');
 
-    let appFile = fs.readFileSync(appFilePath, 'utf8');
-    let vendorFile = fs.readFileSync(vendorFilePath, 'utf8');
+    debug("evaluating app and vendor files");
 
-    debug("evaluating app; app=%s; vendor=%s", appFilePath, vendorFilePath);
-
-    sandbox.eval(vendorFile, vendorFilePath);
+    vendorFilePaths.forEach(function(vendorFilePath) {
+      debug("evaluating vendor file %s", vendorFilePath);
+      let vendorFile = fs.readFileSync(vendorFilePath, 'utf8');
+      sandbox.eval(vendorFile, vendorFilePath);
+    });
     debug("vendor file evaluated");
 
-    sandbox.eval(appFile, appFilePath);
-    debug("app file evaluated");
+    appFilePaths.forEach(function(appFilePath) {
+      debug("evaluating app file %s", appFilePath);
+      let appFile = fs.readFileSync(appFilePath, 'utf8');
+      sandbox.eval(appFile, appFilePath);
+    });
+    debug("app files evaluated");
   }
 
   /**
@@ -153,7 +158,6 @@ class EmberApp {
    */
   createEmberApp() {
     let sandbox = this.sandbox;
-    let appFilePath = this.appFilePath;
 
     // Retrieve the application factory from within the sandbox
     let AppFactory = sandbox.run(function(ctx) {
@@ -162,7 +166,7 @@ class EmberApp {
 
     // If the application factory couldn't be found, throw an error
     if (!AppFactory || typeof AppFactory['default'] !== 'function') {
-      throw new Error('Failed to load Ember app from ' + appFilePath + ', make sure it was built for FastBoot with the `ember fastboot:build` command.');
+      throw new Error('Failed to load Ember app from app.js, make sure it was built for FastBoot with the `ember fastboot:build` command.');
     }
 
     // Otherwise, return a new `Ember.Application` instance
@@ -349,9 +353,33 @@ class EmberApp {
       throw new Error(`${pkgPath} was malformed or did not contain a manifest. Ensure that you have a compatible version of ember-cli-fastboot.`);
     }
 
+    var appFiles = [];
+    if (manifest.appFiles) {
+      debug("reading array of app file paths from manifest");
+      manifest.appFiles.forEach(function(appFile) {
+        appFiles.push(path.join(distPath, appFile));
+      });
+    } else if (manifest.appFile) {
+      // TODO : remove after Fastboot 1.0
+      debug("reading app file path from manifest");
+      appFiles = [path.join(distPath, manifest.appFile)];
+    }
+
+    var vendorFiles = [];
+    if (manifest.vendorFiles) {
+      debug("reading array of vendor file paths from manifest");
+      manifest.vendorFiles.forEach(function(vendorFile) {
+        vendorFiles.push(path.join(distPath, vendorFile));
+      });
+    } else if (manifest.vendorFile) {
+      // TODO : remove after Fastboot 1.0
+      debug("reading vendor file path from manifest");
+      vendorFiles = [path.join(distPath, manifest.vendorFile)];
+    }
+
     return {
-      appFile:  path.join(distPath, manifest.appFile),
-      vendorFile: path.join(distPath, manifest.vendorFile),
+      appFiles:  appFiles,
+      vendorFiles: vendorFiles,
       htmlFile: path.join(distPath, manifest.htmlFile),
       moduleWhitelist: pkg.fastboot.moduleWhitelist,
       hostWhitelist: pkg.fastboot.hostWhitelist,

test/fastboot-test.js

@@ -51,6 +51,18 @@ describe("FastBoot", function() {
       });
   });
 
+  it("can render HTML with array of app files defined in package.json", function() {
+    var fastboot = new FastBoot({
+      distPath: fixture('multiple-app-files')
+    });
+
+    return fastboot.visit('/')
+      .then(r => r.html())
+      .then(html => {
+        expect(html).to.match(/Welcome to Ember/);
+      });
+  });
+
   it("cannot not render app HTML with shouldRender set as false", function() {
     var fastboot = new FastBoot({
       distPath: fixture('basic-app')