Match Ember and Handlebars Versions

Ember is very specific about what version of Handlebars it requires. This is probably good, but it's also a pain to work with as different versions of the two libraries are released independently. There are a few good tools to help us out.

Released Independently

In a prime example, recently there was a new version of Handlebars released: 1.0.0-rc.4. Ember happens to be on version 1.0.0-rc.3. That version has a hard dependency on Handlebars 1.0.0-rc.3. In other words, the latest Ember code relies on an older version of Handlebars.


If you include these 3rd party libraries in your source code under a lib directory or something of that nature, you always have plenty of work to do. Naturally, you just copy in the exact versions of the scripts that are needed.

Hopefully you're trying to make use of a mostly awesome tool, Bower. It helps you manage these 3rd party libraries in a way similar to npm. You provide a descriptor of your project's dependencies, component.json. And you install things similarly via the bower cli.

Specify a Bower Version

If I run:

bower install handlebars --save

It saves a dependency in my components.json for Handlebars for the latest version it could find. This won't do for us. We need to specify the versions.

Our strategy will be: take the latest version of Ember and then specifically match the Handlbars version. Finally, we should type:

bower install ember --save
bower install handlebars#1.0.0-rc.3

As of this writing, that is the version of handlebars that is required. Bower will recognize any semver git tag name or branch name after the hash # sign.

I like our version strategy for a project that is under active development in that it keeps us on the latest Ember. But, if you're on a project that's been built to an Ember version and not deployed for a long time, you may want to make a very specific dependency out of Ember as well, so the two are guaranteed in sync for future deploys.