Invalid code generated when namespaced type is used as return type for async function

[okunokentaro]

tsc 1.6.2 with -t es6 --experimentalAsyncFunctions.

declare namespace ns {
  export type PromiseAlias = Promise<any>;
}

async function f(): ns.PromiseAlias {
  return new Promise((resolve) => {
    resolve();
  });
}

f();

converts to the bellow.

var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promise, generator) {
    return new Promise(function (resolve, reject) {
        generator = generator.call(thisArg, _arguments);
        function cast(value) { return value instanceof Promise && value.constructor === Promise ? value : new Promise(function (resolve) { resolve(value); }); }
        function onfulfill(value) { try { step("next", value); } catch (e) { reject(e); } }
        function onreject(value) { try { step("throw", value); } catch (e) { reject(e); } }
        function step(verb, value) {
            var result = generator[verb](value);
            result.done ? resolve(result.value) : cast(result.value).then(onfulfill, onreject);
        }
        step("next", void 0);
    });
};
function f() {
    return __awaiter(this, void 0, ns.PromiseAlias, function* () {
        return new Promise((resolve) => {
            resolve();
        });
    });
}
f();

throw this error.

return __awaiter(this, void 0, ns.PromiseAlias, function* () {
                               ^
ReferenceError: ns is not defined

ns.PromiseAlias is an alias, doesn't have an implementation. Is this correct? thanks.

[DanielRosenwasser]

@rbuckton @mhegazy

[rbuckton]

@armorik83 You are correct. Since ns.PromiseAlias is an alias, you should see an error at compile time. I've fixed this both in master and release-1.7.