fix(compiler): no need for commenting selectors anymore

[christian-bromann]

What is the current behavior?

With previous versions of Stencil where we didn't not had support for DSD, we used to comment selectors and transform them so that shadow components can by hydrated as scoped components. To have the styles applied properly, we would transform them and keep the original selector commented, e.g.:

- div {font-size:50px;}}';
+ /*!@div*/div.a {font-size:50px;}}';

GitHub Issue Number: fixes #5880

Since component styles are handled at compile time there is no easy way for us to just render define this behavior when calling renderToString. Hence this PR will change the behavior of how shadow components are being serialized. It now doesn't render the shadow DOM anymore if the serializeShadowRoot is set to false. Before Stencil would transform a shadow component into a scoped component. This behavior will be removed with this patch.

To keep Stencil somewhat backwards compatible, I switched the default value for serializeShadowRoot to true.

What is the new behavior?

CSS style text is not transformed into scoped styles anymore, nor there is any selector commenting.

Documentation

Does this introduce a breaking change?

• Yes
• No

Testing

Updated tests and added new ones.

Other information

n/a

[github-actions]

@stencil/core@4.19.2 ts
tsc --noEmit --project scripts/tsconfig.json && tsx scripts/tech-debt-burndown-report.ts

--strictNullChecks error report

Typechecking with --strictNullChecks resulted in 1071 errors on this branch.

That's 7 fewer than on main! 🎉🎉🎉

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/compiler/prerender/prerender-optimize.ts	14
src/compiler/sys/stencil-sys.ts	14
src/runtime/connected-callback.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	327
TS18048	188
TS18047	99
TS2722	27
TS2532	20
TS2531	19
TS2790	11
TS2454	10
TS2352	9
TS2769	8
TS2416	7
TS2538	4
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	21	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/9942946652/artifacts/1702661896

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

unzip -d ~/Downloads ~/Downloads/stencil-core-4.19.2-dev.1721060336.6c5b2a2.tgz.zip && npm install ~/Downloads/stencil-core-4.19.2-dev.1721060336.6c5b2a2.tgz

[tanner-reits]

Love killing code 💪 🪓