☂️ transformer: ES2024 - ES2016

[Boshen]

Need to implement babel plugins equivalent of

• https://github.com/evanw/esbuild/blob/9c13ae1f06dfa909eb4a53882e3b7e4216a503fe/compat-table/src/index.ts#L350-L399
• https://github.com/evanw/esbuild/blob/9c13ae1f06dfa909eb4a53882e3b7e4216a503fe/compat-table/src/kangax.ts#L20-L85

2024 features

• [x] RegexpSetNotation (See "Regex Features" below) https://github.com/evanw/esbuild/commit/b5ec4057eb8e7897360c80011d5b2f46ddbb58ab

2023 features

• [x] Hashbang (syntax)

2022 features

• [ ] ClassField https://babel.dev/docs/babel-plugin-transform-class-properties
• [ ] ClassPrivateAccessor https://babeljs.io/docs/babel-plugin-transform-private-methods
• [ ] ClassPrivateBrandCheck https://babeljs.io/docs/babel-plugin-transform-private-methods
• [ ] ClassPrivateField https://babel.dev/docs/babel-plugin-transform-private-property-in-object
• [ ] ClassPrivateMethod https://babel.dev/docs/babel-plugin-transform-private-methods
• [ ] ClassPrivateStaticAccessor https://babeljs.io/docs/babel-plugin-transform-private-methods
• [ ] ClassPrivateStaticField https://babeljs.io/docs/babel-plugin-transform-private-methods
• [ ] ClassPrivateStaticMethod https://babeljs.io/docs/babel-plugin-transform-private-methods
• [x] ClassStaticBlocks https://babel.dev/docs/babel-plugin-transform-class-static-block
• [ ] ClassStaticField https://babeljs.io/docs/babel-plugin-transform-class-properties
• [x] TopLevelAwait (syntax)
• [x] RegexpMatchIndices (See "Regex Features" below)
• • ArbitraryModuleNamespaceNames can parse correctly, can emit a warning if required https://github.com/evanw/esbuild/commit/d354bbb39d1ccf3774f5f810cc63d8a0171d3a0f

2021 features

• [x] LogicalAssignment https://babel.dev/docs/babel-plugin-transform-logical-assignment-operators @Dunqing #4890

2020 features

• [x] Bigint (syntax)
• [x] ExportStarAs (syntax)
• [x] ImportMeta (syntax)
• [x] NullishCoalescing https://babel.dev/docs/babel-plugin-transform-nullish-coalescing-operator #4884 @Dunqing
• [x] #6958
• [ ] TypeofExoticObjectIsObject minifier feature Minify typeof x !== 'undefined' to typeof x < 'u' https://github.com/evanw/esbuild/commit/81215bcac4da6eba4e24cd62341553f0dc93a3c8

2019 features

• [x] OptionalCatchBinding https://babel.dev/docs/babel-plugin-transform-optional-catch-binding @Dunqing #4885

2018 features

• [x] AsyncGenerator https://babeljs.io/docs/babel-plugin-transform-async-generator-functions
• [x] ForAwait https://babeljs.io/docs/babel-plugin-transform-async-generator-functions
• [x] #6959

  • 3133 covered spread, rest not done yet

• [x] RegexpDotAllFlag (See "Regex Features" below)
• [x] RegexpLookbehindAssertions (See "Regex Features" below)
• [x] RegexpNamedCaptureGroups (See "Regex Features" below)
• [x] RegexpUnicodePropertyEscapes (See "Regex Features" below)

2017 features

• [x] AsyncAwait https://babeljs.io/docs/babel-plugin-transform-async-to-generator

2016 features

• [x] ExponentOperator https://babel.dev/docs/babel-plugin-transform-exponentiation-operator #4876 @Dunqing

---

Regex Features

See https://esbuild.github.io/content-types/#javascript #5387

Unsupported regular expression literals are transformed into a new RegExp() constructor call so you can bring your own polyfill library to get them to work anyway.

[Boshen]

This is not a good first issue yet.

[DonIsaac]

Can we add CJS to this list too? I need this for oxc-jest.

[Boshen]

Can we add CJS to this list too? I need this for oxc-jest.

CJS is in the milestone https://github.com/oxc-project/oxc/milestone/6

[Boshen]

The list is not that bad actually, we end up with a few groups:

• regex features - transform to regex constructor
• class stuff - ClassXXX
• syntax sugars
• Async Generator
• Async Await

[7086cmd]

I want to handle the async/await in ES2017. Currently non-arrow function is well transformed in my codebase.

[overlookmotel]

We had OptionalChain ticked off the list as done. But actually it's not done yet!

ObjectRestSpread was also ticked off, but we've only done half of it.

😢