Bug 247786 – Re-assignment to constant variable in for-in head

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: JavaScriptCore

[Kanguk Lee]

// input.js
const x = 0 ; for ( { x } in [ 1 ] ) ; 
_____________________

Hello,

Executing the input.js using JSC, it terminates normally, but TypeError is expected since there is an assignment to const.

Running the input.js with JSC results in:

---
$ jsc input.js
async
---

while other engines behave like:

---
# V8 (used console.log)
$ node input.js
input.js:1
const x = 0 ; for ( { x } in [ 1 ] ) ;
                      ^

TypeError: Assignment to constant variable.
    at Object.<anonymous> (input.js:1:23)
    at Module._compile (node:internal/modules/cjs/loader:1159:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1213:10)
    at Module.load (node:internal/modules/cjs/loader:1037:32)
    at Module._load (node:internal/modules/cjs/loader:878:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:23:47

Node.js v18.11.0

# GraalJS
$ js input.js
TypeError: Assignment to constant "x"
	at <js> :program(input.js:1:22)
---


WebKit version: 615.1.10

[Radar WebKit Bug Importer]

<rdar://problem/102325113>

[Yijia Huang]

This should be a duplicate of https://bugs.webkit.org/show_bug.cgi?id=247432 and should be fixed in PR https://commits.webkit.org/256580@main.

Just tested on ToT https://commits.webkit.org/256659@main. It is fixed.

*** This bug has been marked as a duplicate of bug 247432 ***