fix(runtime): allow watchers to fire w/ no Stencil members

[tanner-reits]

What is the current behavior?

@Watch() callbacks will not fire for native HTML attributes if there is not at least one Stencil member (@State or @Prop) within the component.

Fixes #5854

What is the new behavior?

Watch callbacks will no correctly fire even if no Stencil members are present

Documentation

Does this introduce a breaking change?

• Yes
• No

Testing

New e2e test added for use case and verified fix in reproduction

Other information

[github-actions]

@stencil/[email protected] ts
tsc --noEmit --project scripts/tsconfig.json && tsx scripts/tech-debt-burndown-report.ts

--strictNullChecks error report

Typechecking with --strictNullChecks resulted in 1077 errors on this branch.

That's the same number of errors on main, so at least we're not creating new ones!

reports and statistics

Our most error-prone files

Path	Error Count
src/dev-server/index.ts	37
src/dev-server/server-process.ts	32
src/compiler/prerender/prerender-main.ts	22
src/runtime/vdom/vdom-render.ts	22
src/runtime/client-hydrate.ts	20
src/runtime/vdom/test/patch.spec.ts	19
src/runtime/vdom/test/util.spec.ts	19
src/screenshot/connector-base.ts	19
src/testing/puppeteer/puppeteer-element.ts	19
src/dev-server/request-handler.ts	15
src/runtime/connected-callback.ts	15
src/compiler/prerender/prerender-optimize.ts	14
src/compiler/sys/stencil-sys.ts	14
src/sys/node/node-sys.ts	14
src/compiler/prerender/prerender-queue.ts	13
src/compiler/sys/in-memory-fs.ts	13
src/runtime/set-value.ts	13
src/compiler/output-targets/output-www.ts	12
src/compiler/transformers/test/parse-vdom.spec.ts	12
src/compiler/transformers/transform-utils.ts	12

Our most common errors

Typescript Error Code	Count
TS2322	338
TS2345	329
TS18048	186
TS18047	99
TS2722	27
TS2532	23
TS2531	19
TS2790	11
TS2454	10
TS2352	9
TS2769	8
TS2416	7
TS2538	4
TS2493	3
TS18046	2
TS2684	1
TS2430	1

Unused exports report

There are 15 unused exports on this PR. That's the same number of errors on main, so at least we're not creating new ones!

Unused exports

File	Line	Identifier
src/runtime/bootstrap-lazy.ts	22	setNonce
src/screenshot/screenshot-fs.ts	18	readScreenshotData
src/testing/testing-utils.ts	198	withSilentWarn
src/utils/index.ts	145	CUSTOM
src/utils/index.ts	245	NODE_TYPES
src/utils/index.ts	269	normalize
src/utils/index.ts	7	escapeRegExpSpecialCharacters
src/compiler/app-core/app-data.ts	25	BUILD
src/compiler/app-core/app-data.ts	116	Env
src/compiler/app-core/app-data.ts	118	NAMESPACE
src/compiler/fs-watch/fs-watch-rebuild.ts	123	updateCacheFromRebuild
src/compiler/types/validate-primary-package-output-target.ts	82	satisfies
src/compiler/types/validate-primary-package-output-target.ts	82	Record
src/testing/puppeteer/puppeteer-declarations.ts	496	WaitForEventOptions
src/compiler/sys/fetch/write-fetch-success.ts	7	writeFetchSuccessSync

[github-actions]

PR built and packed!

Download the tarball here: https://github.com/ionic-team/stencil/actions/runs/9667111866/artifacts/1637168463

If your browser saves files to ~/Downloads you can install it like so:

unzip -d ~/Downloads ~/Downloads/stencil-core-4.18.3-dev.1719337175.e3059cd.tgz.zip && npm install ~/Downloads/stencil-core-4.18.3-dev.1719337175.e3059cd.tgz

[christian-bromann]

🙌