Sets a base directory from which to resolve non-relative module names. For example, in the directory structure:

project
├── ex.ts
├── hello
│   └── world.ts
└── tsconfig.json

project
├── ex.ts
├── hello
│   └── world.ts
└── tsconfig.json

With "baseUrl": "./", TypeScript will look for files starting at the same folder as the tsconfig.json:

import { helloWorld } from "hello/world";

console.log(helloWorld);

import { helloWorld } from "hello/world";

console.log(helloWorld);

This resolution has higher priority than lookups from node_modules.

This feature was designed for use in conjunction with AMD module loaders in the browser, and is not recommended in any other context. As of TypeScript 4.1, baseUrl is no longer required to be set when using paths.