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• Would you like to work on a fix?

How are you using Babel?

Programmatic API (babel.transform, babel.parse)

Input code

See this repo: https://github.com/evanw/decorator-tests

Configuration file name

No response

Configuration

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Current and expected behavior

I'm working on adding stage 3 decorators to esbuild. My first step was to write a lot of tests and run them through the Babel and TypeScript implementations. I'm sending you this issue because I figured you might be interested to learn about the behavior differences that I found. This is not a problem for me as I don't use Babel myself, so feel free to close this issue after reading it if you'd like. Here are the unexpected behaviors I found with Babel's implementation (see the repo for details):

• Decorators on class expressions do not yet use the correct name (Support named evaluation for decorated anonymous class exp #16148).
• The name provided to decorators on private methods (both static and non-static) is empty. (Set function name for decorated private non-field elements #16144)
• The context object property access exposes the underlying getter and setter instead of the Get and Set abstract operations. (fix: decorator binds getter/setter to ctx.access for public fields #16201)
• The context object for fields (both static and non-static) is missing the addInitializer method. (Allow addInitializer in field decorator context #16132)
• Using a private name within a decorator can cause Babel to emit invalid code containing a syntax error. (Fix decorator evaluation private environment #16325)
• References to the class name within a decorator return undefined instead of throwing a ReferenceError if a class decorator is present. (Class binding is in TDZ during decorators initialization #16138)

Caveat: I'm just learning about this feature now, and I'm also not sure how up-to-date the specification is, so it could be that Babel's behavior for some of these is intentional. But if so, that behavior at least differs from TypeScript's implementation, which seems undesirable. FWIW I'm currently mostly planning to align esbuild's behavior to TypeScript since it seems like it matches the specification more closely, so it'd be good to know if Babel's behavior here is actually more correct (e.g. regarding access).

Environment

I can reproduce this by running Babel using https://babel.dev/repl.

Possible solution

No response

Additional context

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