babel-plugin-minify-dead-code-elimination should remove unused arguments

Original issue: https://github.com/babel/babel/issues/4531

Input Code

Here’s a reproduction repo

const foo = (arg1, arg2) => arg1

.babelrc (or what it might look like)

{
  "plugins": ["minify-dead-code-elimination"]
}

Expected Behavior

I would expect the output to be:

const foo = (arg1) => arg1

Current Behavior

Instead, the plugin doesn’t do anything with unused arguments

const foo = (arg1, arg2) => arg1

Possible Solution

I’m not certain whether this is totally the responsibility of babel-plugin-minify-dead-code-elimination, but I can’t think of any other plugin that should do this.

Context

I’m writing a program slicing tool that’s using babel-plugin-minify-dead-code-elimination directly to remove dead code after I’ve manipulated the AST to remove sliced nodes.

Your Environment

software	version
Babel	6.14.0
node	6.5.0
npm	3.10.7
Operating System	Mac OSX

[rajakolluru]

I just figured this one out and did that as we speak. That was a very quick response. Thank you

[nicolo-ribaudo]

You can use the keepFnArgs option to disable this behavior: https://github.com/babel/minify/blob/8b7ed4adfc963f3c84d4a74c18e6a42aadb1396b/packages/babel-plugin-minify-dead-code-elimination/README.md#options