Merge pull request #338 from kellyselden/manual-disable

process.env.FASTBOOT_DISABLED to disable fastboot build

Author: tomdale

README.md

@@ -385,6 +385,21 @@ Prototype extensions do not currently work across node "realms."  Fastboot
 applications operate in two realms, a normal node environment and a [virtual machine](https://nodejs.org/api/vm.html).  Passing objects that originated from the normal realm will not contain the extension methods
 inside of the sandbox environment. For this reason, it's encouraged to [disable prototype extensions](https://guides.emberjs.com/v2.4.0/configuring-ember/disabling-prototype-extensions/).
 
+### Double build times and no incremental builds
+
+Due to limitations in Ember CLI, builds take twice as long to generate the
+second set of FastBoot assets. This also means incremental builds with
+live reload don't work either. This aims to be resolved by FastBoot 1.0.
+In the mean time, we introduce a short-circuit evironment flag to not do
+a FastBoot build:
+
+```
+FASTBOOT_DISABLED=true ember build
+```
+
+This is useful to keep your existing workflow while in development, while
+still being able to deploy FastBoot. This flag will be removed in FastBoot
+1.0.
 
 ## Troubleshooting
 

index.js

@@ -112,9 +112,12 @@ module.exports = {
   /**
    * After the entire Broccoli tree has been built for the `dist` directory,
    * adds the `fastboot-config.json` file to the root.
+   *
+   * FASTBOOT_DISABLED is a pre 1.0 power user flag to
+   * disable the fastboot build while retaining the fastboot service.
    */
   postprocessTree: function(type, tree) {
-    if (type === 'all') {
+    if (type === 'all' && !process.env.FASTBOOT_DISABLED) {
       var fastbootTree = this.buildFastBootTree();
 
       // Merge the package.json with the existing tree
@@ -148,7 +151,7 @@ module.exports = {
     if (emberVersionChecker.version) {
       return emberVersionChecker;
     }
-    
+
     return checker.for('ember', 'bower');
   },