Fix #165, context does not always have appOut property

lib/electronBuilder.js

@@ -46,6 +46,7 @@ export default class InstallerBuilder {
         this.firstPass = true;
         this.lastRebuild = {};
         this.currentContext = null;
+        this.installerDir = path.join(this.$.env.options.output, this.$.env.paths.installerDir);
     }
 
     /**
@@ -131,7 +132,7 @@ export default class InstallerBuilder {
      * Callback to be invoked after packing. Restores node_modules to the .desktop-build.
      * @returns {Promise}
      */
-    afterPack(context) {
+    afterPack() {
         return new Promise((resolve, reject) => {
             shell.config.fatal = true;
 
@@ -140,7 +141,7 @@ export default class InstallerBuilder {
                 shell.cp(
                     '-Rf',
                     this.$.env.paths.electronApp.extractedNodeModules,
-                    path.join(this.getPackagedAppPath(context), 'node_modules')
+                    path.join(this.getPackagedAppPath(), 'node_modules')
                 );
             }
 
@@ -207,18 +208,18 @@ export default class InstallerBuilder {
      * Returns the path to packaged app.
      * @returns {string}
      */
-    getPackagedAppPath(context = {}) {
+    getPackagedAppPath() {
         if (this.currentContext.platform.nodeName === 'darwin') {
             return path.join(
-                context.appOutDir,
+                this.installerDir,
                 `${context.packager.appInfo.productFilename}.app`,
                 'Contents', 'Resources', 'app'
             );
         }
         const platformDir =
             `${this.currentContext.platform.nodeName === 'win32' ? 'win' : 'linux'}-${this.currentContext.arch === 'ia32' ? 'ia32-' : ''}unpacked`;
         return path.join(
-            context.appOutDir,
+            this.installerDir,
             platformDir,
             'resources', 'app'
         );