Mangled generated code mixing ExportAllDeclaration and external source

[usergenic]

• Rollup Version: 0.64.0
• Operating System (or Browser):
• Node Version: 10.9.0

How Do We Reproduce?

Here's a fairly simple reproduction, call it repro.js

var { rollup } = require('rollup');

const files = {
  'file:///a.js': `import * as $b from "file:///b.js"; export { $b };`,
  'file:///b.js': `export * from 'file:///c.js';`,
  'file:///c.js': `export const c = '🤡';`
};

rollup({
  input: 'file:///a.js',
  external: ['file:///c.js'],
  output: { format: 'esm' },
  plugins: [{ name: "somePlugin", resolveId: (id) => id, load: (id) => files[id] }]
}).then((r) => r.generate({ format: 'es' }).then((r) => console.log(r.code)));

Run the repro:

npm install rollup@0.64.0
node repro.js

Expected Behavior

I'd expect something along the lines of the following, but would be happy with anything that achieves

import * as c from 'file:///c.js';
var $b = {
  c: c
};
export { $b };

Actual Behavior

Generates the following mess.

import 'file:///c.js';



var b = /*#__PURE__*/Object.freeze({
  *file:///c.js: *
});

export { b as $b };

[lukastaegert]

This is indeed a tricky one. Your expected result is wrong IMO since if you do

import * as c from 'file:///c.js';

with file:///c.js as given in your example, then the namespace variable c would have the form {c: 🤡}. Thus in your example, $b$ should have this form as well while in your proposed solution, it would have the form {c: {c: 🤡}}.

A valid solution would be

import * as c from 'file:///c.js';
export { c as $b };

However, this is no longer possible if file:///b.js adds other imports, e.g.

// b.js
export * from 'file:///c.js';
export const dontKnowWhatToDoWithThis = 4;

My feeling is that we should try to use the first solution if possible but throw an error in the second case until someone figures out a nice solution that scales well.

[lukastaegert]

Interestingly enough, rollup 0.66 refuses to bundle this code with an internal error...

[lukastaegert]

Not really a fix but a better error message: #2499

[lukastaegert]

Closing this in favour of #2165 as with the correct error message, this missing feature is all that remains.