🔎 Search Terms

• asserts
• assertion function
• type guard
• record

🕗 Version & Regression Information

Worked on 4.9, broken since 5.0

Probably introduced by #52984

⏯ Playground Link

Playground link with relevant code

💻 Code

declare function isObject(o: unknown): o is Record<string, any>

declare function assertObject(o: unknown): asserts o is Record<string, any>  

let value: {} = null!;
if(isObject(value)) {
    value.anything // error since 5.0.2
}

assertObject(value)

value.anything // error since 5.0.2

🙁 Actual behavior

Property 'anything' does not exist on type '{}'.(2339)

🙂 Expected behavior

No error, narrowing / assertion should work fine.