Enum value `1 / 0` incorrectly transformed if there is `Infinity` declared in scope

[nicolo-ribaudo]

Bug Report

🔎 Search Terms

infinity enum variable let shadow

🕗 Version & Regression Information

Every version I tested

⏯ Playground Link

Playground link with relevant code

💻 Code

{
 let Infinity = 3;

 enum A {
 X = 1 / 0
 }

 console.log(A.X)
}

🙁 Actual behavior

{
 let Infinity = 3;
 let A;
 (function (A) {
 A[A["X"] = Infinity] = "X";
 })(A || (A = {}));
 console.log(A.X);
}

and logs 3

🙂 Expected behavior

It should log the result of 1 / 0, which is Infinity.

Somewhat related to #54981.

[nmain]

This also appears to apply to NaN?

{
 let Infinity = 3;
 let NaN = 5;

 enum A {
 X = 1 / 0,
 B = 0 / 0,
 }

 console.log(A.X)
 console.log(A.B)
}

[nicolo-ribaudo]

Yes 👍

[ravin00]

This confusion comes because you're trying to write the global infinity value which will lead to unexpected behaviour.

let Infinity = 3;
You're assigning the value 3 to infinity and it will no longer represent the special value. Insted it will refer to the number 3.

enum A { X = 1 / 0 }

1 / 0 normally show the infinity. But since you have declared the value 3 to the infinity. The x value is will be 3 no the expected infinity.

To get the expected output remove the redefinition of the infinity.
`enum A {
X = 1 / 0
}

console.log(A.X); // This will log Infinity
`

This will log correctly infinity as expected