Long time ago I have started developing one application using Ember 1.0 version, I guess. With time I have successfully upgraded it to the newest version. Now, I would like to switch to ES6 and start using ember cli with existsting project. How can I make it? Is there any upgrading guide? Furthermore should I upgrade to ES6 at this time? Will transpiler cost me much performence lose?
If you are not using ember-cli, I would use this time to start that migration first.
Once you are on ember-cli, you can use the addon by @rwjblue https://github.com/rwjblue/ember-cli-esnext. This will allow you to use all of the features of esnext in your application.
As for performance, I can’t really speak to that. But esnext is a highly vetted project, so it’s a good stop gap until all browsers implement es6.
Just a line to add that, since version 0.1.3, ember-cli-esnext is included by default on every application.
To learn about the subset of ES6 features supported by esnext, check their docs.