TypeScript – [Subsequent property declarations must have the same type] – Multiple references to the same type definitions
Providing “skipLibCheck”: true to tsconfig.json compilerOptions solved problem in my case
definitelytyped
How do I define a knockout binding handler in typescript?
Defining a custom binding handler Its actually pretty easy, just add it (myBindingHandler) to the KnockoutBindingHandlers interface right before you define your custom binding handler. Please note that you have to do make this addition to the interface, within a .d.ts file as of version 1.0 (or possibly earlier). bindingHandlers.d.ts /// <reference path=”typings/knockout/knockout.d.ts” /> interface … Read more
Using getInitialProps in Next.js with TypeScript
Edit 2021/04/23: My answer below is also out of date Please see the Next.js docs for the current recommendation for typing data fetching methods using new types and named exports. tl;dr: import { GetStaticProps, GetStaticPaths, GetServerSideProps } from ‘next’ export const getStaticProps: GetStaticProps = async (context) => { // … } export const getStaticPaths: GetStaticPaths … Read more
Extend interface defined in .d.ts file
// How to extend Validator interface adding isArray() method?? You cannot do this in a file that is a module (some guidance here) and your file is a module because you have import expressValidator. Instead create a extendedValidator.d.ts and add the new stuff for TypeScript’s engine: declare module ExpressValidator { export interface Validator { isArray: … Read more
What is “DefinitelyTyped”?
TypeScript allows you to have Declaration Files which are files that allow you to describe the shape of code that’s written in (for example) plain JavaScript. So, by referencing one of these files you tell TypeScript exactly how that JavaScript code or library you are using should be assumed to be “typed”. Of course, this … Read more
Relationship between the version of node.js and the version of @types/node
Simply, the major version and minor version tagged in the semver string of @types/node is exactly corresponding to the node’s version. If you check the index.d.ts file of @types/node in DefinitelyTyped repository, you’ll see what type of node is this declaration file for through the first line comment at the top of the file: // … Read more
Is there a way to “extract” the type of TypeScript interface property?
It wasn’t possible before but luckily it is now, since TypeScript version 2.1. It has been released on the 7th of December 2016 and it introduces indexed access types also called lookup types. The syntax looks exactly like element access but written in place of types. So in your case: interface I1 { x: any; … Read more
TypeScript getting error TS2304: cannot find name ‘ require’
Quick and Dirty If you just have one file using require, or you’re doing this for demo purposes you can define require at the top of your TypeScript file. declare var require: any TypeScript 2.x If you are using TypeScript 2.x you no longer need to have Typings or Definitely Typed installed. Simply install the … Read more