Assuming you have the following code inside a ES6 class (documentation): /** * @typedef Test~options * @type {object.<string>} * @property {array} elements - An array containing elements ...

I have interface with list of optional properties. export interface OptionalIds { entityA_Id?: number; entityB_Id?: number; entityC_Id?: number; } And I have a requirement that EXACTLY one of t...

When writing type for cb: const fn1 = ( cb: (...args: [...args: any[], fn2: () => string, fn3: () => string]) => any, ...args: any[] ) => { const fn2 = () => 'fn2' const fn3 = ()...

This is my dictionary: type Words = 'man' | 'sun' | 'person' type Dictionary = Record<Words,string> And Dictionary equals to this type: type Dictionary = { man: string; sun: string; perso...

Type alias: type A = string Type definition: type A string What is the difference between them? I can't understand from spec

I know how to extend a TypeScript interface, but what I'm asking here is how to override a particular key in an interface. For example, say I have a simple interface A: interface A { foo: string;...

I'm writing a type definition file (index.d.ts) for a jQuery library that doesn't come with a type definition. The methods of that library repeatedly accept parameters of the same multi-type (strin...

I'm working on an Angular 9 project. I'd like to use a ResizeObserver, but since this type is currently missing from TypeScript's lib.dom.d.ts (issue), I tried to add Jason Strothmann's ResizeObser...

I'm learning Fortran and I'd like to encapsulate an array and a subroutine in a type. The problem appears to be in the type definition of the self-object. This is the minimal test case I came up w...

I am attempting to set up a TypeScript project and get bootstrap 4 working along with Popper, jQuery, and Knockout in Visual Studio Code. I installed the knockout, jquery and bootstrap type defini...

I put up my own typescript project with the Parcel compiler and got everything running on the built-in server. I implemented pixi.js and wanted to import .png files into my .ts files. But when I tr...

Is it legal to have fields with the same name across different anonymous unions inside one union? union Foo { union { int bar; }; union { int bar; }; }; This code fails to compile by GC...

I'm trying create type definitions for an existing suite of stateless React components, so I can generate documentation automagically and to improve intellisense in my team's tooling. An example c...

If I have a TypeScript module saved as my-function.ts as follows : export function myFunction (param: number): number { return param } This will be compiled to JavaScript in whichever way and lo...

I want to write a type definition for storybook-router. It needn't be that accurate, since this is a minor development tool (i.e. anys are acceptable), but I can't even seem to get that to work. W...

Heyho, I want to use some javascript libraries in my typescript code for which there are no typings in npm. So I wrote the typings myself and put them in a definitions directory in my source tree....