Cannot set property 'at' of undefined

[iffy]

For this JS file (which is generated from TypeScript) I'm seeing the error below:

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};

Object.defineProperty(exports, "__esModule", { value: true });
const tap = require("tap");
tap.test('foo', (t) => __awaiter(this, void 0, void 0, function* () {
    yield t.rejects(() => {
        return new Promise((resolve, reject) => {
            reject('foo');
        });
    });
}));

Here's the error:

$ tap test.js
test.js ............................................... 0/2
  foo
  not ok Cannot set property 'at' of undefined
    stack: |
      Object.<anonymous> (test.js:14:13)
      Generator.next (<anonymous>)
      test.js:7:71
      __awaiter (test.js:3:12)
      Test.tap.test (test.js:13:24)
    type: TypeError
    test: foo
  
  not ok undefined
    error: foo
    stack: |
      process.emit (node_modules/source-map-support/source-map-support.js:430:21)
      processEmit [as emit] (node_modules/signal-exit/index.js:155:32)

total ................................................. 0/2
  

  0 passing (395.964ms)
  2 failing

It's generated from this TypeScript file (if that matters):

import * as tap from 'tap';

tap.test('foo', async t => {
  await t.rejects(() => {
    return new Promise((resolve, reject) => {
      reject('foo');
    })
  })
})

Versions:

$ tap --version
10.7.0
$ node --version
v7.4.0

Is this a bug in tap or a bug in TypeScript's await/async-to-generators code?

[ghost]

I have the same for a simple t.rejects(prom, {}, 'a'); in a test function, that makes rejects unusable.