Path mapping & module resolution
Configure path aliases with baseUrl/paths, understand how TS resolves modules, and avoid common pitfalls.
Path mapping & module resolution is a free TypeScript Academy lesson on CoddyKit. This is lesson 3 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the TypeScript Academy learning path, and your progress syncs across the web and the CoddyKit app. The TypeScript Academy course includes 3 lessons in total.
Intro
Goal: Replace long relative imports with path aliases and understand TypeScript`s module resolution rules to keep imports clean.
tsconfig paths
Set baseUrl (project root for non-relative imports) and map aliases in paths. Keys can use * globs.
// file: tsconfig.json (excerpt)
{
"compilerOptions": {
"baseUrl": "./src",
"paths": {
"@utils/*": ["utils/*"],
"@components/*": ["components/*"]
}
}
}Use alias
Import using the alias exactly as declared (e.g., @utils/date). TypeScript resolves to the mapped path in src/.
// file: src/app.ts
import { formatDate } from "@utils/date";
import Button from "@components/Button";
console.log(formatDate(new Date()));
const btn = new Button();Resolution strategy
Resolution depends on module (Node, NodeNext, Bundler). TS checks file extensions, package.json exports/types, then falls back to node_modules.
// Resolution order sketch (NodeNext/Node):
// 1) Exact file: .ts/.tsx/.d.ts/.js
// 2) Index files: index.ts / index.js
// 3) package.json exports / types
// 4) paths & baseUrl fallbacks
// 5) node_modules lookup (upwards)
export const note = "Resolution depends on module setting (Node, NodeNext, Bundler).";Bundler alignment
Important: TS knows aliases for type-checking, but your bundler/runtime must also map them (e.g., Vite/Webpack/tsconfig-paths for ts-node).
// Example: vite.config.ts (alias for runtime)
import { defineConfig } from "vite";
import path from "path";
export default defineConfig({
resolve: {
alias: {
"@utils": path.resolve(__dirname, "src/utils"),
"@components": path.resolve(__dirname, "src/components")
}
}
});Tips & pitfalls
Tips:
- Keep baseUrl stable (e.g., src/).
- Mirror aliases in bundler/runtime.
- Avoid deep ../.. chains; prefer concise aliases.
Path alias check
Quick check: Which tsconfig options enable path aliases like @utils/*?
Recap
Recap: Configure baseUrl and paths for aliases, learn TS resolution order, and align bundler/runtime to avoid broken imports.
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Frequently Asked Questions
Is the “Path mapping & module resolution” lesson free?
Yes — the full text of “Path mapping & module resolution” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the TypeScript Academy course, upgrade to CoddyKit PRO. The TypeScript Academy course includes 3 lessons in total.
What will I learn in “Path mapping & module resolution”?
Configure path aliases with baseUrl/paths, understand how TS resolves modules, and avoid common pitfalls. You practise TypeScript Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start TypeScript Academy?
No prior experience is required. TypeScript Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 3 of 3.
How long does the “Path mapping & module resolution” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this TypeScript Academy lesson?
Yes. Every TypeScript Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- ES Modules (named vs default), re-exports
- Ambient declarations (.d.ts) & third-party typings
- Path mapping & module resolution