Here is how to do this as of Typescript 2.0: (tsd and typings are being deprecated in favor of the following):

$ npm install --save lodash

# This is the new bit here: 
$ npm install --save-dev @types/lodash

Then, in your .ts file:

Either:

import * as _ from "lodash";

Or (as suggested by @Naitik):

import _ from "lodash";

I'm not positive what the difference is. We use and prefer the first syntax. However, some report that the first syntax doesn't work for them, and someone else has commented that the latter syntax is incompatible with lazy loaded webpack modules. YMMV.

Edit on Feb 27th, 2017:

According to @Koert below, import * as _ from "lodash"; is the only working syntax as of Typescript 2.2.1, lodash 4.17.4, and @types/lodash 4.14.53. He says that the other suggested import syntax gives the error "has no default export".

You don't want to create a new debounced function every time you change quantity and certainly not on every render.

Here I've wrapped the original fetchPrice with the debounce function and also saved state so we can use the same debounced function across renders.

const [debouncedFetchPrice] = useState(() => debounce(fetchPrice, 1000));

and then in changeQty function you should call debouncedFetchPrice instead of fetchPrice

This should mean it will trigger with the latest desiredPurchaseQty value after a 1000 millis delay.

Furthermore...

I've found this article useful in the past to create a useDebounce hook with useEffect. Check it out https://dev.to/gabe_ragland/debouncing-with-react-hooks-jci

I found two three possible working scenarios:

1. Use TSdx, the Zero-config CLI for TypeScript package development. https://tsdx.io/
2. Use lodash-es instead (but note that chains are not working in lodash-es!). Explanation below. This however still gives Jest errors when this library is imported in another library, and tested there.
3. Use vitest instead. Vitest is largely compatible with the Jest api. After installing Vitest, everything simply worked, without any configuration. The only thing to do is to add import { assert, expect, test } from 'vitest' to your tests. If you have just started, and only have simple tests, they simply worked without any changes (YMMV). In addition, both lodash and lodash-es worked fine.

A better answer would include a scenario that uses "plain" lodash, or explains why lodash-es is actually a good thing. From what I'm reading in various posts is that lodash-es has several drawbacks (results in a larger bundle size, chains don't work).

Here is a working setup with (I think) sensible defaults. This library is for internal use, and I run Node 18, so I use a high target version here.

package.json

{
  "name": "@vexna/util",
  "version": "1.0.0",
  "description": "Generic utilities, uses lodash",
  "private": true,
  "type": "module",
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "sideEffects": false,
  "scripts": {
    "build": "rimraf dist && tsc && rollup -c rollup.config.js",
    "test": "node test/spec",
    "pretest": "npm run build"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@rollup/plugin-typescript": "^11.0.0",
    "@types/lodash-es": "^4.17.6",
    "lodash-es": "^4.17.21",
    "rimraf": "^4.1.2",
    "rollup": "^3.12.1",
    "typescript": "^4.9.5"
  },
  "files": [
    "dist"
  ],
  "peerDependencies": {
    "lodash": "^4.17.21"
  }
}

tsconfig.ts

{
    "compilerOptions": {
      "module": "es2022",
      "moduleResolution": "node",
      "outDir": "dist",
      "declaration": true,
      "sourceMap": true,
      "esModuleInterop": true,
      "allowSyntheticDefaultImports": true,
      "forceConsistentCasingInFileNames": true,
      "lib": ["es2022", "DOM", "DOM.Iterable"],
      "target": "es2022",
      "skipLibCheck": true,
      "strict": true,
      "exactOptionalPropertyTypes": true,
      "noImplicitAny": true,
      "noImplicitThis": true,
      "checkJs": true
    },
    "include": ["./src/**/*.ts"]
}

rollup.config.js

import typescript from '@rollup/plugin-typescript'
const input = ["src/index.ts"]

export default [
    {
        input,
        plugins: [
            typescript()],
        output: [
            {
                dir: "dist",
                sourcemap: true,
            }
        ],
        external: ['lodash-es'],
    }
]

The output has lodash entirely externalized, so very small bundle! As a precaution, I added "lodash": "^4.17.21" to the "peerDependencies". This is a little odd cause it's a mismatch with devDependencies (which uses the -es), but this seems fine. YMMV.

In the library code, you can import the lodash functions like so:

import { now, random, padStart } from "lodash-es"

A project that consumes this library must have lodash, and can import like so:

import { createUid } from '@vexna/util'

This definition is incorrect

throttledWindowScroll?: typeof throttle

Using throttle returns T & Cancelable. typeof throttle on the other hand is a function. Change it to

throttledWindowScroll: ReturnType<typeof throttle>