Problem Statement
Provide types for a JS-only lib:
Explanation
First look for community typings on DefinitelyTyped (`@types/...`). If none exist, write your own `.d.ts` declaration file for the library.
Code Solution
SolutionRead Only
// Install typings:
// npm i -D @types/lodash
// Or create: types/my-lib/index.d.ts
declare module 'my-lib' { export function doThing(): void }