Allow decorators to be used with declare on class fields (#19492)

Co-authored-by: fisker <lionkay@gmail.com>

changelog_unreleased/typescript/19492.md

@@ -0,0 +1,23 @@
+#### Allow decorators to be used with declare on class fields (#19492 by @evoactivity)
+
+Extensively used within the Ember ecosystem, decorators with `declare` on class fields will ignore the babel parser error and allow Prettier to format the code without breaking it.
+
+<!-- prettier-ignore -->
+```ts
+// Input
+export default class ProjectStatusComponent extends Component<ProjectStatusSig> {
+  @service declare server: ServerService;
+}
+
+// Prettier stable
+// SyntaxError: Decorators can't be used with a declare field. (2:3)
+//  1 | export default class ProjectStatusComponent extends Component<ProjectStatusSig> {
+//> 2 |   @service declare server: ServerService;
+//    |   ^
+//  3 | }
+
+// Prettier main
+export default class ProjectStatusComponent extends Component<ProjectStatusSig> {
+  @service declare server: ServerService;
+}
+```