When I enable noImplicitThis in tsconfig.json, I get this error for the following code: ‘this’ implicitly has type ‘any’ because it does not have a type annotation. class Foo implements EventEmitter { on(name: string, fn: Function) { } emit(name: string) { } } const foo = new Foo(); foo.on(‘error’, function(err: any) { console.log(err); this.emit(‘end’); // … Read more
What is the purpose of the declare keyword? type Callback = (err: Error | String, data: Array<CalledBackData>) => void; vs. declare type Callback = (err: Error | String, data:Array<CalledBackData>) => void; Cannot find docs that explain the purpose of the declare keyword in TS. 6 Answers 6
What does Record<K, T> mean in Typescript? Typescript 2.1 introduced the Record type, describing it in an example: // For every properties K of type T, transform it to U function mapObject<K extends string, T, U>(obj: Record<K, T>, f: (x: T) => U): Record<K, U> see Typescript 2.1 And the Advanced Types page mentions Record … Read more
I have a very simple functional component as follows: import * as React from ‘react’; export interface AuxProps { children: React.ReactNode } const aux = (props: AuxProps) => props.children; export default aux; And another component: import * as React from “react”; export interface LayoutProps { children: React.ReactNode } const layout = (props: LayoutProps) => ( … Read more
