How to test Angular2 pipe in nodejs with mocha without karma

I'd like to be able to test an Angular2 pipe purely in nodejs environment without including karma etc.

It is possible to use typescript files as test suites for mocha

http://ift.tt/2dbCMDn

But when I have a import {Pipe} from '@angular/core' it gives me

/Users/foo/node_modules/@angular/core/src/util/decorators.js:173
        throw 'reflect-metadata shim is required when using class decorators';
        ^
reflect-metadata shim is required when using class decorators

Even if I write require('reflect-metadata') in my test file it still breaks with the same error.

Angular internally has this check:

(function checkReflect() {
    if (!(Reflect && Reflect.getMetadata)) {
        throw 'reflect-metadata shim is required when using class decorators';
    }
})();

And after requireing reflect-matadata I indeed have Reflect on the global object, however it still doesn't work...

Anyway is there a way to test an Angular pipe purley in nodejs with mocha?

I'm using webpack to bundle the app so the file I'm requring in my test file looks like this:

import {Pipe} from '@angular/core';

@Pipe({
    name: 'filterBy'
})

export class FilterByPipe {
  transform(items = [], prop, val) {
    return items.filter(someFilteringAlgorithm(prop, val));
  }
}