Are there any BundleTransformer JS minifiers that support ES6?

Question

Are there any JS minifiers for BundleTransformer that support EcmaScript 6? I have tried installing:

• BundleTransformer.Closure
• BundleTransformer.YUI
• BundleTransformer.UglifyJs

But neither seem to handle the string template syntax of ES6, such as:

`Hello ${world}`

Am I missing something, or is it time to upgrade to Node + X?

Answer 1

Tormod!

Suppose you have the following code:

var world = 123;
alert(`Hello ${world}`);

Only two minifiers from the Bundle Transformer can process it:

1. MicrosoftAjaxJsMinifier from BundleTransformer.MicrosoftAjax. It just minify a ES6 code.

2. ClosureLocalJsMinifier from BundleTransformer.Closure with the following configuration settings:

   <?xml version="1.0" encoding="utf-8"?>
   <configuration>
     …
     <bundleTransformer xmlns="http://tempuri.org/BundleTransformer.Configuration.xsd">
       …
       <closure>
         <js>
           …
           <local closureCompilerApplicationPath="…"
             javaVirtualMachinePath="…"
             languageInput="EcmaScript6" languageOutput="EcmaScript3" />
           …
         </js>
       </closure>
       …
     </bundleTransformer>
     …
   </configuration>
   

The transpilation from ES6 to ES3 will be made, and then the ES3 code will be minified. In addition, to the languageOutput attribute can be set the following values: EcmaScript5 and EcmaScript5Strict.