Missing computed properties in declaration emit

[DanielRosenwasser]

With #60052, we now emit qualified names rather than generate an index signature for computed names in classes; however, this now puts us in an awkward place where regardless of errors, declaration emit diverges on isolatedDeclarations.

Playground Links:

• 5.7, without isolatedDeclarations
• Nightly, without isolatedDeclarations
• Nightly, with isolatedDeclarations

export const greeting: unique symbol = Symbol();
export const count: unique symbol = Symbol();

export class MyClass1 {
 [greeting]: string = "world";
 [count]: number = 42;
}

export enum PropertyNames {
 greeting = "greeting",
 count = "count",
}

export class MyClass2 {
 [PropertyNames.greeting]: string = "world";
 [PropertyNames.count]: number = 42;
}

export let prop!: string;

export class MyClass3 {
 [prop]: () => void = () => {}
}

Compared to --isolatedDeclarations false The declaration emit lacks expected contents in MyClass1 and MyClass2:

 export declare const greeting: unique symbol;
 export declare const count: unique symbol;
 export declare class MyClass1 {
- [greeting]: string;
- [count]: number;
 }
 export declare enum PropertyNames {
 greeting = "greeting",
 count = "count"
 }
 export declare class MyClass2 {
- [PropertyNames.greeting]: string;
- [PropertyNames.count]: number;
 }
 export declare let prop: string;
 export declare class MyClass3 {
 [prop]: () => void;
 }

It is surprising that prop is emitted regardless of --isolatedDeclarations, but not the other contents.

[DanielRosenwasser]

After talking to people on our side, the assessment is

1. It would be nice if these divergences didn't exist
2. but they're okay because emit in the face of errors is sort of undefined behavior
3. though it's pretty weird that we wouldn't do the most obvious syntactic thing
4. but it might be fine regardless because Wesley Wigham (@weswigham) is working on allowing computed properties to work in isolatedDeclarations.

So if someone wants to correct the divergence, great! Otherwise, this should be fixed in the future.