I was struggling with the same problem and actually it turns out that a simple change seems to do the trick. I just updated the moduleDirectories field in jest.config.js. Before moduleDirectories: [‘node_modules’] After moduleDirectories: [‘node_modules’, ‘src’] Hope it helps.
It doesn’t inherit from Element because not all event targets are elements. From MDN: Element, document, and window are the most common event targets, but other objects can be event targets too, for example XMLHttpRequest, AudioNode, AudioContext, and others. Even the KeyboardEvent you’re trying to use can occur on a DOM element or on the … Read more
TL;DR Just write export {} in the outermost scope of your files. At some point there needs to be a semantic disambiguation for whether a file should be treated as a module (and have its own scope) or a script (and share the global scope with other scripts). In the browser, this is easy – … Read more
One more solution if you don’t want to create a new pipe. You could also extract keys into helper property and use it: @Component({ selector: ‘my-app’, providers: [], template: ` <div> <select> <option *ngFor=”let key of keys” [value]=”key” [label]=”countries[key]”></option> </select> </div> `, directives: [] }) export class App { countries = CountryCodeEnum constructor() { this.keys … Read more
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
let timer: ReturnType<typeof setTimeout> = setTimeout(() => { … }); clearTimeout(timer); By using ReturnType<fn> you are getting independence from platform. You won’t be forced to use neither any nor window.setTimeout which will break if you run the code on nodeJS server (eg. server-side rendered page). Good news, this is also compatible with Deno!
TypeScript does not know that there are files other than .tsor .tsx so it will throw an error if an import has an unknown file suffix. If you have a webpack config that allows you to import other types of files, you have to tell the TypeScript compiler that these files exist. To do so … Read more
“Magically available interfaces” or global types is highly discouraged and should mostly be left to legacy. Also, you should not be using ambient declaration files (e.g. d.ts files) for code that you are writing. These are meant to stand-in the place of external non-typescript code (essentially filling in the typescript types into js code so … Read more
Your best bet is to throw an Error wrapping the value, which results in a rejected promise with an Error wrapping the value: } catch (error) { throw new Error(400); } You can also just throw the value, but then there’s no stack trace information: } catch (error) { throw 400; } Alternately, return a … Read more
Canonical answers to this question can be found in: The TypeScript FAQ entry for “Why are functions returning non-void assignable to function returning void?” microsoft/TypeScript#8581 “how come () => void is a subtype of () => a if void isn’t a subtype of a and a isn’t subtype of void?” microsoft/TypeScript#20006 “[documentation] Clarify the semantics … Read more