Inconsistent ending for type

I believe that the one we should have is what flow is outputting. Does someone have more context around why there’s a difference here?

Flow

--parser babel

export type Block = {
  format: BlockFormat,
  lang: BlockLanguage
}

Typescript

--parser typescript

type Block = {
  format: BlockFormat;
  lang: BlockLanguage;
};

[thorn0]

Object types in TS are anonymous interfaces. They can contain everything named interfaces can, e.g. method signatures, which look really strange with commas:

let a: {
    foo(): number,
    bar(): string,
    bar(baz: string): void,
    (): void,
};

The relationship between object types and interfaces closely resembles the one between function expressions and function declarations. A function expression can be assigned to a variable (let f = ...) to achieve almost the same effect a function declaration would have, but still function declarations have some extra behavior, namely hoisting. Same with object types and interfaces. If you assign an object type to an alias (type t = ...), it will be almost the same thing as an interface declaration, but it won’t have the extra behavior interface declarations have, namely declaration merging.

The point I’m making is that using different formatting for object types and interfaces is very much like using different formatting for function expressions and function declarations. Not only inconsistent, it’d be also misleading, making object types and interfaces look more different than they actually are.

[seahindeniz]

I didn’t read that before and now did.

Everybody wants to add just a tiny piece of configuration to satisfy their use case. As a result we end up with inconsistently designed tools, with unexpected combinations that don’t work correctly, with bugs and regressions that, when fixed in one configuration, break something else with another configuration.

I can say and confirm that this isn’t directly related to my use case. I’m simply referring is that Typescript has support for comma delimiter since 2015 and there is no enforcement that restricts us to use semicolon in type/interface definitions. We can agree there isn’t going to be a bug in both usages, am I right?

Btw. the tab width example is just to show that you there is no restriction between both usages, therefore, there shouldn’t be for delimiters.