Improving TypeScript's default behavior

ts-reset is a utility that extends TypeScript's standard typing by removing outdated and non-strict parts of the core API. It is added at the project level and increases the strictness of typing in a number of APIs.

Installation

npm install --save-dev ts-reset

// reset.d.ts
import "@total-typescript/ts-reset";

It is also possible to set individual rules:

// reset.d.ts
// Makes JSON.parse return unknown
import "@total-typescript/ts-reset/json-parse";
// Makes await fetch().then(res => res.json()) return unknown
import "@total-typescript/ts-reset/fetch";

Main changes

• JSON.parse, .json(), localStorage, sessionStorage now return unknown instead of any
• .filter(Boolean) correctly removes falsy values
• .includes(), .indexOf(), Set.has(), Map.has() do not require exact comparison (which is what we are trying to achieve by calling them)
• Array.isArray() no longer considers any[] safe

⚠️ Not recommended for use in libraries, as changes to global types may affect end projects where the library will be installed.

Within existing projects, connecting ts-reset usually does not cause problems: types become stricter but remain compatible with correct code. If errors appear after connecting, these are most likely areas where typing was already unsafe.