TypeScript + power-assert + ES6 Modules issue http://qiita.com/wadahiro/items/5d8a81252f2105112339

test.js

// generated .js
var power_assert_1 = require('power-assert');
var _1 = require('../');
describe('foo', function () {
    it('test #1', function () {
        power_assert_1.default.ok(_1.default() === 2);
    });
});

test.ts

// original .ts
import assert from 'power-assert';
import sut from '../';

describe('foo', () => {
    it('test #1', () => {
        assert.ok(sut() === 2);
    });
});

一度変数に戻せばいけるけど、このtipsに気づいてもらうのは難しそう。

import powerAssert from 'power-assert';
import sut from '../';

const assert = powerAssert;

describe('foo', () => {
    it('test #1', () => {
        assert.ok(sut() === 2);
    });
});