Include use of TS declare syntax #583
Open
+3
−1
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
TS can use class fields with decorators without turning off useDefineForClassFields at the cost of losing inline initialisation see lit#479 and lit/lit#1985 for discussion
es2020 will cause useDefineForClassFields to default to true
|
Requesting a review from @sorvell who wrote the current section. |
There was a problem hiding this comment.
@KeithHenry sorry this review took so long! The declare info was already added, but the es2020 bit wasn't, if you care to resubmit.
| @@ -130,6 +130,8 @@ constructor() { | |||
|
|
|||
| For **TypeScript**, you **may use class fields** for declaring reactive properties as long as the `useDefineForClassFields` setting in your `tsconfig` is set to `false`. Note, this is not required for some configurations of TypeScript, but it's recommended to explicitly set it to `false`. | |||
|
|
|||
| For **TypeScript**, you can use `declare` syntax for class fields that you explicitly want to exclude from the JS output regardless of the `useDefineForClassFields` setting. This will allow you to use decorators, but cannot be initialised inline. Similar to JS declared fields can only be initialised in the `constructor`. | |||
There was a problem hiding this comment.
Looks like this info was added at some point. It would be nice to get a link to https://www.typescriptlang.org/docs/handbook/2/classes.html#type-only-field-declarations in there though.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
TS can use class fields with decorators without turning off
useDefineForClassFieldsat the cost of losing inline initialisation.See #479 and lit/lit#1985 for discussion.
Also clarified version, as
es2020or above will causeuseDefineForClassFieldsto default totrue, not justesnext. See microsoft/TypeScript#45653