How can I run a Node 6 npm package in a Node 5.6.0 environment?

Question

I'm currently using a package for running cross browser javascript tests called easy-sauce . In short, my package.json file calls that for the test command:

{
  "scripts": {
    "test": "easy-sauce"
  }
}

When I'm using a Node 6 environment, and run npm test , all is well. However, the project I'm using it with still needs Node 5.6.0. When I run npm test in this environment, I see the following error:

/data/projects/easytest/node_modules/easy-sauce/lib/cli.js:114
function formatResult(result = {}) {
                         ^

SyntaxError: Unexpected token =
at exports.runInThisContext (vm.js:53:16)
at Module._compile (module.js:387:25)
at Object.Module._extensions..js (module.js:422:10)
at Module.load (module.js:357:32)
at Function.Module._load (module.js:314:12)
at Module.require (module.js:367:17)
at require (internal/module.js:16:19)
at Object.<anonymous> (/data/projects/easytest/node_modules/easy-sauce/bin/easy-sauce:6:13)
at Module._compile (module.js:413:34)
at Object.Module._extensions..js (module.js:422:10)

Is there a way to get this working within the Node 5.6.0 environment?

Answer 1

This error isn't related to the easy-sauce package, it has to do with your version of node.

According to node.green, default parameters were added in version 6.2.2

http://node.green/

Unfortunately you wont be able to run the code in node 5. Default parameters are in node 6.2, hence that error.

Answer 2

Option 1 Upgrade your version of node/npm. This is not always possible, depending on deployment environment.

Option 2 You need to use a transpiler (eg Babel) to convert the ES6 code to ES5 and reference the built script. This solution is the one you always have the power to do.

Option 3 Fork/update easy-sauce to include a transpiler to build an ES5 version (in the dist folder is a common destination). The package.json of the package can be directed to this location.