Can't create array larger than 2**26 items

[julienp]

Version

v24.0.0

Platform

Darwin macbook-pulumi.local 24.4.0 Darwin Kernel Version 24.4.0: Fri Apr 11 18:33:47 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_T6030 arm64

Subsystem

No response

What steps will reproduce the bug?

Works:

Array.from("a".repeat(2**26))

Fails:

Array.from("a".repeat(2**26+1))
Uncaught RangeError: Invalid array length
    at Array.from (<anonymous>)

In v22.15.0 this works fine.

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

It should be possible to create arrays with 2**32 elements.

What do you see instead?

RangeError: Invalid array length

Additional information

No response

[ljharb]

There's nothing in the language spec that requires engines to have an array that long; however, Array.from({ length: 67108865 }) also fails in both node 24 and chrome, so it might be a v8-specific regression?

[juanarbol]

It is definitely a V8 engine issue.

[juanarbol]

I think there is a misunderstanding here.

"a".repeat(kTimes) returns a single string with "a....aaaa-kTimes"; that is a single element.

The issue is not about the number of elements but its size in memory.

NVM, I think I found the issue from the V8 engine.

v8/v8@0c36aff

That commit just messes around with the Array length and it was introduced to the V8 v13.x-series

[RafaelGSS]

Maybe related https://github.com/RafaelGSS/nodejs-bench-operations/actions/runs/14866441608/job/41744580099. This benchmark runs successfully on all previous Node.js versions except v24.

[indus]

I think there is a misunderstanding here.

"a".repeat(kTimes) returns a single string with "a....aaaa-kTimes"; that is a single element.

The issue is not about the number of elements but its size in memory.

NVM, I think I found the issue from the V8 engine.

v8/v8@0c36aff

That commit just messes around with the Array length and it was introduced to the V8 v13.x-series

I think it is this commit: v8/v8@298c285#diff-de4a87761282d00872530bdaa015b6f4e6407bf6b553ee7919a4f85f6f460812L32

It cuts the max length almost in half.
It hurts my work a lot - but I'm unsure how to get in contact with the V8 team.

[LeszekSwirski]

Once Node catches up to https://chromium-review.googlesource.com/c/v8/v8/+/6597277, you'll get double the max size again (more than it used to be even).