Maximum call stack size exceeded with two mapped types #57786

🔎 Search Terms

"Maximum call stack size exceeded", "mapped types"

🕗 Version & Regression Information

• This is a crash

⏯ Playground Link

https://www.typescriptlang.org/play?ts=5.4.2#code/C4TwDgpgBAYg9nAPANQHxQLxQN4CgoFQDaA0lAJYB2UA1hCHAGZTIC6AXLAiqa6gNy4AvrlyhIUAEIBDAE4p0WPIWJkqtekxYcWvKBAAewCJQAmAZyhwARgCsIAY2BQA-FLk8SfKJ3PBZVADmgiK4jACulE7kcNTGfgoAFABu0gA24RCc8EhoAJQ4+FAOseZwaRAAdGlwgSnpmXkhoiWUflDWcpwy8tKUIIo4QoJiEH6JnbJNuEA

💻 Code

type Foo<V> = {
    [K in keyof V]: Foo<V[K]>;
}

type Bar<V> = {
    [K in keyof V]: V[K] extends object ? Bar<V[K]> : string;
}

function test<V>(value: Foo<V>) {
  console.log(value);
}

const bar: Bar<any> = {};

test(bar);

🙁 Actual behavior

Throws an exception

Uncaught (in promise) RangeError: Maximum call stack size exceeded

🙂 Expected behavior

Either passes type check or reports a problem

Additional information about the issue

No response