Move ReactiveController and Host to core

[OS-paulvisciano]

Exposing ReactiveController and Host publicly to make it easier to implement the pattern and also provide a common interface community members can use to create and share Controllers

What is the current behavior?

The classes were internal to the tests

What is the new behavior?

Exposed as part of the public API

Documentation

For more info on Reactive Controllers

https://stenciljs.com/docs/extends

Does this introduce a breaking change?

• Yes
• No

Testing

Existing tests using the Reactive controller pattern now import the implementation from core and pass.

[Copilot]

Pull request overview

This pull request moves the ReactiveController interface and ReactiveControllerHost class from internal test files into the public Stencil Core API. This enables developers to use the reactive controller pattern for component composition, similar to patterns found in frameworks like Lit.

Changes:

• Moved ReactiveController and ReactiveControllerHost from test-local implementations to src/runtime/reactive-controller.ts as public exports
• Updated all test files to import from @stencil/core instead of local ./reactive-controller-host.js files
• Added proper TypeScript type declarations in stencil-public-runtime.ts

Reviewed changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/runtime/reactive-controller.ts	Implements the ReactiveController interface and ReactiveControllerHost class with lifecycle hooks
src/runtime/index.ts	Exports ReactiveController and ReactiveControllerHost from the runtime module
src/declarations/stencil-public-runtime.ts	Adds public TypeScript type declarations for the reactive controller API
src/internal/stencil-core/index.d.ts	Exports the new public types and classes in the main API surface
src/compiler/transformers/update-stencil-core-import.ts	Adds ReactiveController and ReactiveControllerHost to KEEP_IMPORTS list
src/hydrate/platform/index.ts	Re-exports the new API for server-side rendering support
test/wdio/ts-target/extends-composition-scaling/reactive-controller-host.ts	Deleted - local implementation replaced by public API
test/wdio/ts-target/extends-via-host/mouse-controller.ts	Updated import to use @stencil/core
test/wdio/ts-target/extends-via-host/cmp.tsx	Updated import to use @stencil/core
test/wdio/ts-target/extends-composition-scaling/validation-controller.ts	Updated import to use @stencil/core
test/wdio/ts-target/extends-composition-scaling/text-input-cmp.tsx	Updated import to use @stencil/core
test/wdio/ts-target/extends-composition-scaling/radio-group-cmp.tsx	Updated import to use @stencil/core
test/wdio/ts-target/extends-composition-scaling/focus-controller.ts	Updated import to use @stencil/core
test/wdio/ts-target/extends-composition-scaling/checkbox-group-cmp.tsx	Updated import to use @stencil/core

Comments suppressed due to low confidence (1)

src/runtime/reactive-controller.ts:62

• Extra blank line at end of file should be removed.

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[Copilot]

The type declaration shows componentWillLoad() returns Promise<void> | void, but the actual implementation in src/runtime/reactive-controller.ts (line 38-40) doesn't return anything and only calls controller hooks. The declaration should match the implementation's return type or the implementation should properly handle async controller hooks.

Suggested change

	componentWillLoad(): Promise<void> | void;
	componentDidLoad(): void;
	componentWillRender(): Promise<void> | void;
	componentDidRender(): void;
	componentWillUpdate(): Promise<void> | void;
	componentWillLoad(): void;
	componentDidLoad(): void;
	componentWillRender(): void;
	componentDidRender(): void;
	componentWillUpdate(): void;

[gnbm]

@OS-paulvisciano can you please check this out ☝🏻

[gnbm]

@OS-paulvisciano Two checks are failing:

• CI / Lint and Format / Check (pull_request)
  CI / Lint and Format / Check (pull_request)Failing after 46s
  Required
• CI / WebdriverIO Tests / Run WebdriverIO Component Tests (CHROME) (pull_request)
  CI / WebdriverIO Tests / Run WebdriverIO Component Tests (CHROME) (pull_request)

And ideally it would be good practice to use signed commits

[johnjenkins]

I believe this list are imports that actively have a runtime component - ReactiveController is an interface only(?) so shouldn't be here

[johnjenkins]

again - I don't think an interface should be in this list