Circular Type References in TypeScript

Question

I am new to typescript and am trying to understand how I can setup a circular reference between two types. The reference need not be a full code reference, simply the interfaces, but with interfaces defined in separate files. For example, let's say I have two interfaces: Parent and Child. They are doubly-linked such that the parent has a collection of children and each child has a reference to the parent (as seen below). How do I setup the imports or dependencies so that these can be defined in separate files?

interface Parent {   children: Child[] }  interface Child {   parent: Parent } 

Answer 1

I also faced with the similar situation.

I could resolve by using import type.

https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-8.html

Answer 2

Two solutions below. I prefer the latter since it offers clean interfacing with Node JS modules, but unfortunately my IDE doesn't (yet) like it as much as I do...

Use references

Create a definitions.d.ts file that will only contain the references to your classes/interfaces

/// <reference path="Parent.ts" /> /// <reference path="Child.ts" /> 

In Parent.ts and Child.ts, point to a single reference, the definitions.d.ts file

/// <reference path="definitions.d.ts" /> 

Use import...require

pass the --module commonjs flag to tsc then import what you require and export what you want to expose

In Parent.ts

 import Child = require('Child')   interface Parent {       children: Child[]  }   export = Parent 

In Child.ts

 import Parent = require('Parent')    interface Child {      parent: Parent  }   export = Child 

Please note, that you do not specify the extension '.ts' in require