Typescript error?

[BraunTom]

Maybe it is because I am inexperienced with Typescript, but if you import something in Typescript it tries to load the default property of the exported object, which gives me the error:

new flatten_js_1.default.Point(x, y);
TypeError: Cannot read property 'Point' of undefined

because in the index.js is only module.exports = f (if I change it to
module.exports.default = f;
it fixes the problem for me)

[SamuelQZQ]

I have the same problem.

import Flatten from 'flatten-js';

When I import like this in Typescript, Flatten is undefined.

In the index.js, if I change module.exports = f to module.exports.default = f fixes the problem for me.

But I think that's not the best solution.

[OldrichDlouhy]

Use the following syntax to import flatten in Typescript:

import * as flatten from "flatten-js";

[SamuelQZQ]

My problem has been solved. I think it's nothing about this library, but my own fault. Maybe this issue can be closed?

[alexbol99]

I am also not so experienced with TypeScript but the last suggestion seems correct for now. Later I am planning to redesign the library to es6 modules, then TypeScript support will be more straightforward.

[alexbol99]

I've just found that moving to es6 module system (import/export) make things even less straightforward.
In this discussion is recommended to add following setup to compilerOptions in tsconfig.json file

"compilerOptions": {
   ...
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true
  },

@SamuelQZQ , can you check if this works in your case?

[SamuelQZQ]

I import like this :

import Flatten from 'flatten-js';

If I do not use "esModuleInterop": true in tsconfig.json, Flatten will be undefined. So, your setup works for me.

My full compilerOptions

{
  "compilerOptions": {
    "outDir": "./dist/",
    "sourceMap": true,
    "noImplicitAny": true,
    "module": "commonjs",
    "target": "es2017",
    "jsx": "react",
    "allowJs": true,
    "downlevelIteration": true,
    "esModuleInterop": true,
    "lib": [
      "es6",
      "es2017",
      "dom"
    ]
  }
}