Invalid code "class exports.Foo" emitted for TypeScript's decorators

[IgorMinar]

Given this code with decorators:

@Injectable()
class Testability() {}

Typescript transpiles this into a more verbose version of this es6 code:

export let Testability = class Testability {};
Testability = __decorate([
    Injectable(),
], Testability);

function __decorate(decorators, target) {
  return target;
}

function Injectable() {}

If code like this is processed by rollup, rollup will emit invalid code that looks like:

(function (exports) {
  'use strict';

  exports.Testability = class exports.Testability {};
  exports.Testability = __decorate([
      Injectable(),
  ], exports.Testability);

  function __decorate(decorators, target) {
    return target;
  }

  function Injectable() {}

}((this.rollbug = this.rollbug || {})));
//# sourceMappingURL=rollbug.umd.js.map

Note the class exports.Testability part which is syntactically invalid es6 code.

I'd expect the class to be emitted as exports.Testability = class Testability{ ...

rollup config:

export default {
  entry: 'rollbug.js',
  dest: 'rollbug.umd.js',
  sourceMap: true,
  format: 'iife',
  moduleName: 'rollbug'
}

rollup version: 0.26.0

[Rich-Harris]

Simpler repro:

export let Foo = class Foo {}
Foo = lol( Foo );

Results in:

'use strict';

exports.Foo = class exports.Foo {}
exports.Foo = lol( exports.Foo );

[Rich-Harris]

Thanks @IgorMinar – have opened #628 to address this