compiler: Handle TSNonNullAssertion expressions

[henryqdineen]

Summary

We ran React compiler against part of our codebase and collected compiler errors. One of the more common non-actionable errors is caused by usage of the ! TypeScript non-null assertion operation:

(BuildHIR::lowerExpression) Handle TSNonNullExpression expressions

It seems like React Compiler should be able to support this by just ignoring the syntax and using the underlying expression. I'm sure a lot of our non-null assertion usage should not exist and I understand if React Compiler does not want to support this syntax. It wasn't obvious to me if this omission was intentional or if there are future plans to use TSNonNullExpression as part of the compiler's analysis. If there are no future plans it seems like just ignoring it should be fine.

How did you test this change?

❯ yarn snap --filter
yarn run v1.17.3
$ yarn workspace babel-plugin-react-compiler run snap --filter
$ node ../snap/dist/main.js --filter
 PASS  non-null-assertion
1 Tests, 1 Passed, 0 Failed

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Name	Status	Preview	Comments	Updated (UTC)
react-compiler-playground	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 22, 2024 6:02pm

[react-sizebot]

Comparing: 3ac551e...cff78dd

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.js	=	6.66 kB	6.66 kB	+0.05%	1.82 kB	1.82 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	495.89 kB	495.89 kB	=	88.82 kB	88.83 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.67 kB	6.67 kB	=	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	500.69 kB	500.69 kB	=	89.51 kB	89.51 kB
facebook-www/ReactDOM-prod.classic.js	=	593.05 kB	593.05 kB	=	104.32 kB	104.32 kB
facebook-www/ReactDOM-prod.modern.js	=	569.27 kB	569.27 kB	=	100.72 kB	100.72 kB
test_utils/ReactAllWarnings.js	Deleted	64.35 kB	0.00 kB	Deleted	16.05 kB	0.00 kB

Significant size changes

Includes any change greater than 0.2%:

Expand to show

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
test_utils/ReactAllWarnings.js	Deleted	64.35 kB	0.00 kB	Deleted	16.05 kB	0.00 kB

Generated by 🚫 dangerJS against cff78dd

[josephsavona]

Awesome, thanks for the contribution! We may eventually choose to use information from non-null assertions in some additional ways, but we'd test any such changes carefully. This makes sense to enable.

Thanks again!