Declaration emit for private identifiers in class expressions is wrong

[sandersn]

Code

const O = class { #g }

Expected behavior:

declare const O = class { #private }

Actual behavior:

declare const O: {
    new (): {
        "__#1@#g": any;
    };
};

[a-tarasyuk]

@sandersn Should the ClassExpression be converted like ClassDeclaration?

For the following example, TS converts a variable value to type with the createTypeOfDeclaration, and in the checker, it seems that createAnonymousTypeNode doesn't handle cases for private identifiers.

const O = class { #g }

TypeScript/src/compiler/transformers/declarations.ts

Line 959 in d68295e

return cleanup(updateTypeScriptVariableDeclaration(input, input.name, /*exclaimationToken*/ undefined, ensureType(input, input.type), ensureNoInitializer(input)));

TypeScript/src/compiler/transformers/declarations.ts

Line 507 in d68295e

return cleanup(resolver.createTypeOfDeclaration(node, enclosingDeclaration, declarationEmitNodeBuilderFlags, symbolTracker));

cc @rbuckton

[sandersn]

That seems plausible. @rbuckton knows the transformer a lot better than I do though. Does that sound right to you?

[rbuckton]

I'm not sure we can emit the declare const x = class { ... } form, as we generally use that to preserve literal type freshness. However, its possible we could leverage #41587 to address this with something like this:

declare const x = typeof class { #private };