What happened to the esprima-six npm module?

Question

My npm project has the esprima-six npm module as a transitive dependency. Recently, it has become impossible to download, as seen in the following output from npm install:

npm ERR! 404 Not Found
npm ERR! 404 
npm ERR! 404 'esprima-six' is not in the npm registry.
npm ERR! 404 You should bug the author to publish it
npm ERR! 404 It was specified as a dependency of 'syntax-error'
npm ERR! 404 
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, or http url, or git url.

On the npm site, esprima-six cannot be found: https://www.npmjs.com/package/esprima-six

But Google's cache for the page shows that it used to exist: http://webcache.googleusercontent.com/search?q=cache:81uuMFHrDeMJ:https://www.npmjs.com/package/esprima-six+&cd=1&hl=en&ct=clnk&gl=uk&client=ubuntu

So why did the module become unavailable? And what is the best way to get my project building again?

Edit: in the end I updated the dependency which depended on esprima-six to a later version which didn't need it.

Answer 1

esprima-six has been unpushlished and is no more.

It's hard to track down what exactly has happened, but it seems that esprima-six was a module based on the unofficial harmony branch of the project that has been discountinoud in May 2015, following the deprecation of esprima-fb (a fork that added JSX syntax).

And now esprima-six is no longer needed, as Esprima 2.0 officially supports ES6.

What is the best way to get my project building again?

The stance of Ariya Hidayat, Esprima's maintainer, is that you should just switch to Esprima 2.x.

My project has the esprima-six npm module as a transitive dependency.

In that case, it's probably enough to update your direct dependency, they will have switched already.