identifier mangler on default parameters

[Sorte1]

Describe the bug

When passing an identifier as a default parameter valuee, i doest work

the error seems to come from "babel-plugin-minify-mangle-names/lib/scope-tracker.js" line 47

Expected Behaviour

function a(a, b = 0, c = a, d = 30) {
  return a;
}

Code

function func(adad, arg2 = 0, arg3 = adad, arg4 = 30) {
  return arg1;
}

or 

```js 
let adad = 1
function func(arg1, arg2 = 0, arg3 = adad, arg4 = 30) {
  return arg1;
}

### Logs

```Text
TypeError: Cannot read properties of undefined (reading 'add')
    at ScopeTracker.addReference (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/babel-plugin-minify-mangle-names/lib/scope-tracker.js:47:34)
    at ReferencedIdentifier (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/babel-plugin-minify-mangle-names/lib/index.js:202:26)
    at newFn (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/@babel/traverse/lib/visitors.js:195:17)
    at bfsTraverse (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/babel-plugin-minify-mangle-names/lib/bfs-traverse.js:38:43)
    at Mangler.collect (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/babel-plugin-minify-mangle-names/lib/index.js:235:7)
    at Mangler.run (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/babel-plugin-minify-mangle-names/lib/index.js:60:12)
    at Object.exit (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/babel-plugin-minify-mangle-names/lib/index.js:546:19)
    at NodePath._call (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/@babel/traverse/lib/path/context.js:46:20)
    at NodePath.call (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/@babel/traverse/lib/path/context.js:36:17)
    at NodePath.visit (/home/sorte/.npm/_npx/6da011cd7208f74f/node_modules/@babel/traverse/lib/path/context.js:90:8)

Node.js v18.16.0

[Sorte1]

a possible but not ideal fix would just be moving the variable assignment down

let adad = 1
function func(arg1, arg2 = 0, arg3 , arg4 = 30) {
  arg3 = adad
  return arg1;
}

[j4k0xb]

Yeah that's a known issue: https://github.com/babel/minify/issues/1023 It doesn't seem to be maintained anymore and isn't really the right tool (as it optimizes for 1 letter names and gzip compression rather than readability)

Your suggested fix could work with some changes so I'll try applying it for now, but the name mangling will eventually be redesigned from scratch: #21

let adad = 1
// dummy default param to retain arguments.length and func.length == 1 behaviour
function func(arg1, arg2 = 0, arg3 = undefined , arg4 = 30) {
  if (arg3 === undefined) arg3 = adad; // only set when the arg isn't passed
  return arg1;
}

[j4k0xb]

Could you check if everything works now? https://deploy-preview-42--webcrack.netlify.app/

[Sorte1]

this file gives me the same error

raw-game.zip

[j4k0xb]

works fine for me

[Sorte1]

I just tried it again, and now it works...

[j4k0xb]

oops had a bug in it, !== should be ===

[Sorte1]

when i looked at it, i was like thats not gonna work, but then i got distracted and forgot to write the comment

[Sorte1]

when will this fix be released?

[j4k0xb]

I released it now