fix(mock-doc): add getAttributeNode to mock elements

[tanner-reits]

What is the current behavior?

Use of pseudo selectors in Stencil tests can result in errors due to mock elements not having the getAttributeNode method used by Sizzle

Closes: #3043, #3588

What is the new behavior?

Adds a definition for getAttributeNode to Mock Doc's MockElement

Does this introduce a breaking change?

• Yes
• No

Testing

Manual testing

Verified fix via reproduction case for #3588

Automated testing

Added unit tests to Mock Doc's test suite for the new method

Other information

[github-actions]

--strictNullChecks error report

Typechecking with --strictNullChecks resulted in 1383 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/mock-doc/serialize-node.ts	36
src/dev-server/server-process.ts	32
src/compiler/build/build-stats.ts	27
src/compiler/output-targets/dist-lazy/generate-lazy-module.ts	25
src/compiler/style/test/optimize-css.spec.ts	23
src/testing/puppeteer/puppeteer-element.ts	23
src/compiler/prerender/prerender-main.ts	22
src/runtime/client-hydrate.ts	19
src/screenshot/connector-base.ts	19
src/runtime/vdom/vdom-render.ts	18
src/compiler/config/test/validate-paths.spec.ts	16
src/dev-server/request-handler.ts	15
src/compiler/prerender/prerender-optimize.ts	14
src/compiler/sys/stencil-sys.ts	14
src/compiler/transpile/transpile-module.ts	14
src/runtime/vdom/vdom-annotations.ts	14
src/sys/node/node-sys.ts	14
src/compiler/build/build-finish.ts	13
src/compiler/prerender/prerender-queue.ts	13

Our most common errors

Typescript Error Code	Count
TS2345	412
TS2322	392
TS18048	310
TS18047	101
TS2722	38
TS2532	34
TS2531	23
TS2454	14
TS2352	13
TS2769	10
TS2790	10
TS2538	8
TS2344	5
TS2416	4
TS2493	3
TS2488	2
TS18046	2
TS2684	1
TS2430	1

Unused exports report

There are 14 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	269	normalize
src/utils/index.ts	7	escapeRegExpSpecialCharacters
src/compiler/app-core/app-data.ts	25	BUILD
src/compiler/app-core/app-data.ts	115	Env
src/compiler/app-core/app-data.ts	117	NAMESPACE
src/compiler/fs-watch/fs-watch-rebuild.ts	123	updateCacheFromRebuild
src/compiler/types/validate-primary-package-output-target.ts	61	satisfies
src/compiler/types/validate-primary-package-output-target.ts	61	Record
src/testing/puppeteer/puppeteer-declarations.ts	485	WaitForEventOptions
src/compiler/sys/fetch/write-fetch-success.ts	7	writeFetchSuccessSync