fix: Fix TypeScript iterator support. (#43)

Author: sainthkh

lib/simple_tsify.js

@@ -33,6 +33,7 @@ module.exports = function (b, opts) {
           compilerOptions: {
             esModuleInterop: true,
             jsx: 'react',
+            downlevelIteration: true,
           },
         }).outputText)
       }

test/fixtures/typescript/math_spec.ts

@@ -15,4 +15,9 @@ context('math.ts', function () {
   it('test ts-typed variable', function () {
     expect(x).to.eq(3)
   })
+  it('test iterator', () => {
+    const arr = [...Array(100).keys()]
+
+    expect(arr[0] + arr[1]).to.eq(1)
+  })
 })