Type compatibilty of Record is evaluated differently when aliased

[Fredx87]

Bug Report

🔎 Search Terms

record alias generic function argument type compatibility evaluation

🕗 Version & Regression Information

4.9.3

• This changed between versions 4.1 and 4.2

⏯ Playground Link

Playground link with relevant code

💻 Code

type MyKey = "foo" | "bar";

type Alias = Record<MyKey, string>;

declare function fn1(param: Record<MyKey, string>): void;
declare function fn2(param: Alias): void;

declare const x: Record<string, string>;

// Ok:
fn1(x)

// Error:
fn2(x)

🙁 Actual behavior

When a function has an argument with a Record with a generic key, it is possible to pass a Record<string, string> if the parameter type is declared inline, but the compiler returns an error if the parameter type is a alias.

🙂 Expected behavior

The behavior should be the same independent of how the parameter type is defined.

[fatcerberus]

#49852 (comment)

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.