javascript - Unit testing Typescript decorators -

i have application built on typescript decorators convenience property assignments , wondering how can go writing unit tests them.

 export function apiurl() {         return function (target: any, key: string) {              let _value = target[key];            function getter() {             return _value;           }            function setter(newvalue) {             _value = getapiurl();           }            if (delete target[key]) {             object.defineproperty(target, key, {                 get: getter,                 set: setter             });           }         };     } 

in spec class have,

 it("should return url string", ()=> {    @apiurl();    let baseurl:string;     expect(baseurl typeof string).tobe(true)  }) 

since decorators functions suggest test them other function. , if need to, add 1 tests shows how use decorator class/member/...

here example such test like:

import test 'ava'; import { apiurl } './path';  const decorate = new apiurl();  test.before(t => {   let obj = { someprop: 'foo' };   decorate(obj, 'someprop');   t.context.foo = obj; });  test('should return original value', t => {   t.is(t.context.foo.someprop, 'foo'); });