Bug: Error thrown when iterating a dynamically created anonymous array

[elyran]

• Version: v9.3.0
• Platform: Windows 10 64-bit
• Subsystem: require

error-test.json

{
  "a": 1,
  "b": 2
}

error-test.js

const json = require('./error-test.json')
console.log(json)
[ 11, 22 ].forEach((value) => console.log(value))

Output:

E:\tmp>node error-test.js
{ a: 1, b: 2 }
E:\tmp\error-test.js:4
[ 11, 22 ].forEach((value) => console.log(value))
^

TypeError: Cannot read property '22' of undefined
at Object. (E:\tmp\error-test.js:4:1)
at Module._compile (module.js:660:30)
at Object.Module._extensions..js (module.js:671:10)
at Module.load (module.js:573:32)
at tryModuleLoad (module.js:513:12)
at Function.Module._load (module.js:505:3)
at Function.Module.runMain (module.js:701:10)
at startup (bootstrap_node.js:194:16)
at bootstrap_node.js:618:3

[Solution A] Assigning the array a variable name first wouldn't throw an error:

const json = require('./error-test.json')
console.log(json)
const values = [ 11, 22 ]
values.forEach((value) => console.log(value))

[Solution B] Adding a semicolon to the console.log(json) call would fix the error. That is:
console.log(json);
And that makes me wonder if the error is in the require module/subsystem or maybe it's related to the array.

Thanks!

[vsemozhetbyt]

I think the cause is the semicolon omission, your code is parsed in this way:

console.log(json)[ 11, 22 ].forEach();

ie:

console.log(json) -> undefined
undefined[ 11, 22 ] ->  undefined[ 22 ]

[gireeshpunathil]

simplest recreate:

console.log()
[0]

while the missing semi-colon is understood to be the root cause, I would say the v8's source parser could do better here than coalescing them together to make a single expression. reference

[gireeshpunathil]

interestingly, mozilla console also behaves the same. Looking for any documented evidence that support this behavior

[bnoordhuis]

That's ASI (automatic semicolon insertion) for you. Working per spec, not a bug. Closing.