Destructuring assignment fails in 0.2 and 0.3 with babel7

[diervo]

Input Code

function x() {
    const { method } = $api;
}

Actual Output

TypeError: undefined: Duplicate declaration "b" (This is an error on an internal node. Probably an internal error.)
    at File.buildCodeFrameError (/x/node_modules/@babel/core/lib/transformation/file/file.js:207:12)
    at Scope.checkBlockScopedCollisions (/x/node_modules/@babel/traverse/lib/scope/index.js:303:27)
    at Scope.registerBinding (/x/node_modules/@babel/traverse/lib/scope/index.js:485:16)
    at Scope.registerDeclaration (/x/node_modules/@babel/traverse/lib/scope/index.js:404:14)
    at Object.BlockScoped (/x/node_modules/@babel/traverse/lib/scope/index.js:146:28)
    at Object.newFn (/x/node_modules/@babel/traverse/lib/visitors.js:266:17)
    at NodePath._call (/x/node_modules/@babel/traverse/lib/path/context.js:64:19)
    at NodePath.call (/x/node_modules/@babel/traverse/lib/path/context.js:34:14)
    at NodePath.visit (/x/node_modules/@babel/traverse/lib/path/context.js:99:12)
    at TraversalContext.visitQueue (/x/node_modules/@babel/traverse/lib/context.js:135:18)

Expected Output

function x() {
  var _$api = $api,
    a = _$api.method;
}

Details

I narrow down the bug to the babel-plugin-minify-mangle-names plugin.

This reproduces in preset package 0.2 and 0.3 when using babel 7.0.0-beta.40 (I know is not officially support it yet, but since a trivial example fails, I wonder if there will more of these bugs).

I will try to figure out the root cause and submit a PR, but in the mean time any hints from the owners of the code will be appreciated.

[boopathi]

Thanks for trying this out with babel-7.

I'm debugging this right now and fixed the mentioned issue (Duplicate declaration), but after this fix, there is something else that's broken as well. I will fix that and update.

[diervo]

@boopathi let me know how I can help, is there a branch I can take a look at?
Once you figure out a fix I can push our own packages to get over the hump.

[boopathi]

I pushed to the branch: babel-7

PR - #487

[diervo]

Thanks for the quick turnaround will give it a run and report back

[boopathi]

babel-7 is merged to master.