Fixed "Expected jsx identifier" error on TypeScript generics & angle bracket type assertions in .ts files

[leroydev]

fixes #30456, fixes #30376

This PR makes sure *.ts files don't get interpreted as TSX to fix the following TypeScript concepts from causing errors:
Generics:
class MyClass<T> {};
Angle bracket type assertions:
const myVar = <any>'test';

Note that the last link states that the angle-bracket syntax can be used except if the code is in a .tsx file. So I think it should be possible to use this syntax in a regular .ts file.

I tested this on a pretty big private codebase with 660 .tsx files and 746 .ts files in which both of the concepts above are used regularly, with this change I don't encounter any errors. :)

Bug

• Related issues linked using fixes #number
• Integration tests added -> I couldn't find a correlating integration test, feel free to link it as comment and I'll try to add an integration test
• Errors have helpful link attached, see contributing.md -> PR doesn't add new errors

[mateusmirandaalmeida]

the correction is very good, just wait for the analysis of the @ijjk

[timneutkens]

This looks good 👍 It's just missing an integration test, I'll add one 👍

[timneutkens]

Great catch @leroydev! I've added some tests for the cases you've outlined so that it will not break in the future 👍

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
buildDuration	22.5s	22.4s	-126ms
buildDurationCached	4.8s	4.7s	-87ms
nodeModulesSize	294 MB	294 MB	⚠️ +313 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.891	3.559	-0.33
/ avg req/sec	642.51	702.36	+59.85
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.939	1.86	-0.08
/error-in-render avg req/sec	1289.3	1344.27	+54.97

Client Bundles (main, webpack, commons)

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	28 kB	28 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	71.9 kB	71.9 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
_app-HASH.js gzip	1.23 kB	1.23 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	635 B	635 B	✓
image-HASH.js gzip	4.44 kB	4.44 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	1.87 kB	1.87 kB	✓
routerDirect..HASH.js gzip	321 B	321 B	✓
script-HASH.js gzip	383 B	383 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
334f979574ae..6f4.css gzip	106 B	106 B	✓
Overall change	13.1 kB	13.1 kB	✓

Client Build Manifests

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
index.html gzip	534 B	534 B	✓
link.html gzip	546 B	546 B	✓
withRouter.html gzip	528 B	528 B	✓
Overall change	1.61 kB	1.61 kB	✓

---

Default Build with SWC

General Overall increase ⚠️

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
buildDuration	24.2s	24.8s	⚠️ +561ms
buildDurationCached	4.7s	4.6s	-57ms
nodeModulesSize	294 MB	294 MB	⚠️ +313 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.779	3.652	-0.13
/ avg req/sec	661.48	684.6	+23.12
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.892	1.921	⚠️ +0.03
/error-in-render avg req/sec	1321.55	1301.14	⚠️ -20.41

Client Bundles (main, webpack, commons)

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	28.2 kB	28.2 kB	✓
webpack-HASH.js gzip	1.43 kB	1.43 kB	✓
Overall change	72.1 kB	72.1 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
polyfills-a4..dd70.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
_app-HASH.js gzip	1.22 kB	1.22 kB	✓
_error-HASH.js gzip	180 B	180 B	✓
amp-HASH.js gzip	305 B	305 B	✓
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	622 B	622 B	✓
image-HASH.js gzip	4.46 kB	4.46 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	1.91 kB	1.91 kB	✓
routerDirect..HASH.js gzip	314 B	314 B	✓
script-HASH.js gzip	375 B	375 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
334f979574ae..6f4.css gzip	106 B	106 B	✓
Overall change	13.1 kB	13.1 kB	✓

Client Build Manifests

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	leroydev/next.js fixed-jsx-error-on-typescript-generics-and-angle-bracket-type-assertions	Change
index.html gzip	535 B	535 B	✓
link.html gzip	548 B	548 B	✓
withRouter.html gzip	529 B	529 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: fb1c347