Skip to content

Fix Caveats about props in TS with Options API #1853

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 25, 2022
+3 −3
Merged

Fix Caveats about props in TS with Options API #1853

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions src/guide/typescript/options-api.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -67,7 +67,7 @@ export default defineComponent({

### Caveats

Because of a [design limitation](https://github.com/microsoft/TypeScript/issues/38845) in TypeScript, you have to be careful when using function values for `validator` and `default` prop options - make sure to use arrow functions:
If your TypeScript version is less than `4.7`, you have to be careful when using function values for `validator` and `default` prop options - make sure to use arrow functions:

```ts
import { defineComponent } from 'vue'
Expand All @@ -82,7 +82,7 @@ export default defineComponent({
props: {
bookA: {
type: Object as PropType<Book>,
// Make sure to use arrow functions
// Make sure to use arrow functions if your TypeScript version is less than 4.7
default: () => ({
title: 'Arrow Function Expression'
}),
Expand All @@ -92,7 +92,7 @@ export default defineComponent({
})
```

This prevents TypeScript from having to infer the type of `this` inside these functions, which, unfortunately, can cause the type inference to fail.
This prevents TypeScript from having to infer the type of `this` inside these functions, which, unfortunately, can cause the type inference to fail. It was a previous [design limitation](https://github.com/microsoft/TypeScript/issues/38845), and now has been improved in [TypeScript 4.7](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-7.html#improved-function-inference-in-objects-and-methods).

## Typing Component Emits

Expand Down