Helpers missing from output file for a TS script (instead of module)

I get a Uncaught ReferenceError: __awaiter is not defined when compiling a file with async. I’m using the latest TypeScript (2.6.2), rollup (0.53.0) and plugin (0.9.0).

main.ts

async function main() {
}
main();

rollup.config.js

import typescript from 'rollup-plugin-typescript2';

export default {
  output: {
    format: 'iife'
  },
  plugins: [
    typescript()
  ]
}

tsconfig.json

{
  "compilerOptions": {
    "lib": [
      "es2015"
    ]
  }
}

main.js:

(function () {
'use strict';

function main() {
    return __awaiter(this, void 0, void 0, function () {
        return __generator(this, function (_a) {
            return [2 /*return*/];
        });
    });
}
main();

}());

[ezolenko]

This is in 0.10.0

[mohd-akram]

I modified rollup-plugin-typescript2.cjs.js in node_modules to remove noEmitHelpers: true and didn’t find any duplicates of __awaiter. I then removed importHelpers: true which caused __awaiter$1 to be added to the output. Both modules had async functions in them.

To test with tsc:

tsc main.ts --importHelpers --module es2015 --lib es2015 --moduleResolution node

main.ts:

import f from './module';

async function main() {
  await f();
}
main();

module.ts:

async function f() {
}
export default f;

main.js:

import * as tslib_1 from "tslib";
import f from './module';
function main() {
    return tslib_1.__awaiter(this, void 0, void 0, function () {
        return tslib_1.__generator(this, function (_a) {
            switch (_a.label) {
                case 0: return [4 /*yield*/, f()];
                case 1:
                    _a.sent();
                    return [2 /*return*/];
            }
        });
    });
}
main();

module.js

import * as tslib_1 from "tslib";
function f() {
    return tslib_1.__awaiter(this, void 0, void 0, function () {
        return tslib_1.__generator(this, function (_a) {
            return [2 /*return*/];
        });
    });
}
export default f;