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Update TypedArray constructors to disallow invalid (typedArray, byteOffset, byteLength) #44191
Description
lib Update Request
Configuration Check
My compilation target is ES2020 and my lib is the default.
Missing / Incorrect Definition
TypedArray constructors allows passing (TypedArray, byteOffset, byteLength), when only byteOffset and byteLength are only used when passing in an ArrayBuffer
Sample Code
const buf = new ArrayBuffer(1024);
const uint8 = new Uint8Array(buf, 16, 128)
// No TS error, even though the `16` and `32` are completely ignored
const subUint8 = new Uint8Array(uint8, 16, 32)
subUint8.byteLength // Oops, this is 128, not 32.Documentation Link
new Uint8Array(); // new in ES2017
new Uint8Array(length);
new Uint8Array(typedArray);
new Uint8Array(object);
new Uint8Array(buffer);
new Uint8Array(buffer, byteOffset);
new Uint8Array(buffer, byteOffset, length);
Activity
RyanCavanaugh commentedon Sep 7, 2026
The constructor call from the report is now rejected. TypeScript 6.0.3 and current native TypeScript 7.1.0-dev.20260906.1 report TS2769 because the overload with
byteOffsetandlengthrequires anArrayBufferorArrayBufferLikeas its first argument; another typed array does not match that overload.TypeScript 4.3.2 accepted the call, so its offset and length arguments could be ignored at runtime.