Angular v20: Type-Check Your Host Bindings with `typeCheckHostBindings`

Hey Devs 👋

Have you ever explored the Angular Language Service?
We often use it for goodies like autocompletion, hover tooltips, and go-to-definition. But with Angular v20, there's a new feature in town worth checking out:
typeCheckHostBindings

This feature lets Angular type-check your component's host bindings—meaning if you make a typo or reference a non-existent property, you'll get an immediate error.

Sounds awesome, right? Let's see how to enable and use it.

Step 1: Enable It in tsconfig.json

Add the following under angularCompilerOptions:

"angularCompilerOptions": {
  "typeCheckHostBindings": true
}

This tells the Angular compiler to validate any expressions used in your host bindings.

---

Step 2: Add Host Bindings to a Component

Here’s a quick example:

import { Component } from '@angular/core';

@Component({
  selector: 'app-admin',
  standalone: true,
  template: `
    <p>You are logged in as admin</p>
  `,
  styles: ``,
  host: {
    '[style.color]': 'color',
    '[style.font-size.px]': 'fontSize',
  }
})
export class Admin {
  color = 'red';
  fontSize = 16;
}

In the host section, we bind styles to the color and fontSize properties. Thanks to typeCheckHostBindings, Angular will now:

✅ Let you go to definition for these properties
❌ Show an error if a property doesn’t exist

Example Error

If you forget to define color or fontSize, you’ll see an error like:

Property 'color' does not exist on type 'Admin'.

No more silent mistakes or head-scratching bugs!

Why It Matters

This feature might seem small, but it helps:

• Catch typos and missing props early
• Improve type safety
• Make host bindings more reliable and developer-friendly

Final Thoughts

typeCheckHostBindings is a great little upgrade that helps keep your components clean and error-free. If you're using host bindings, this will absolutely level up your dev experience.

Upgrade to Angular v20 and give it a shot!

💬 Got questions or use cases you want to share? Drop a comment below! Let's discuss more Angular magic. ✨

✍️ Author: Vetriselvan

👨‍💻 Frontend Developer | 💡 Code Enthusiast | 📚 Lifelong Learner | ✍️ Tech Blogger | 🌍 Freelance Developer