type AcceptedClass = "one" | "two" | "three";

type ClassName = `${AcceptedClass} ${ClassName}`;

const className: ClassName = "one two three";
const className2: ClassName = "two one three one three";
const className3: ClassName = "three";
const className4: ClassName = "three one two three one two";

I'd like to create type like code (below), But there's something error

Type alias 'ClassName' circularly references itself.ts(2456)

Is it not possible make that types in typescript?

CodePudding user response：

You cannot have a circular dependency when using type literals.

Think about it like this:

• TS needs replace ${ClassName} with all the possibilities that ClassName can take
• When you use ${ClassName} inside the definition of ${ClassName} it will need to include the 1st iteration for ClassName
• This will go on for ever.

Templated types are fully extended so you cannot have an unbounded type, which you are trying to do. TS has a hard limit of 100k terms in a union type.

You could use something like this, but with limited availability:

const type ClassName = `${AcceptedClass} ${AcceptedClass} ${AcceptedClass} ${AcceptedClass}`;