spread operator [...map] produces incorrect results when values are undefined

[codehz]

What happened

as title

What you expected

Got invalid value

Minimal reproduction

// Minimal reproduction for Perry Map spread operator bug
// The spread operator [...map] produces incorrect results when values are undefined

const map = new Map();
map.set(-4398046512128, undefined);

const spread = [...map];
const arrayFrom = Array.from(map);

console.log("spread length:", spread.length);
console.log("arrayFrom length:", arrayFrom.length);

// In standard JS, both should be equal
console.log("spread[0]:", spread[0]);
console.log("arrayFrom[0]:", arrayFrom[0]);

// This is the actual bug: spread[0] is not an array [key, value]
if (Array.isArray(spread[0])) {
  console.log("spread[0][0]:", spread[0][0]);
  console.log("spread[0][1]:", spread[0][1]);
  console.log("PASS: spread works correctly");
} else {
  console.log("FAIL: spread[0] is not an array, got:", typeof spread[0], spread[0]);
}

// Verify Array.from works correctly
if (Array.isArray(arrayFrom[0]) && arrayFrom[0][0] === -4398046512128 && arrayFrom[0][1] === undefined) {
  console.log("PASS: Array.from works correctly");
} else {
  console.log("FAIL: Array.from also broken");
}

Command you ran:

# e.g. perry compile main.ts -o app --target ios-simulator

Environment

• Perry version: 0.5.619
• Host OS: ArchLinux
• Target: native
• Rust toolchain (if building from source):
• Installed via:

Diagnostic output

Perry Doctor

Environment Checks
──────────────────
  ✓ perry version: 0.5.619
  ✓ update status: up to date
  ✓ clang (LLVM codegen): clang version 22.1.3
  ✓ system linker (cc): cc (GCC) 16.1.1 20260430
  ✓ runtime library: target/release/libperry_runtime.a
  ⚠ project config (perry.toml): not found - run: perry init

All critical checks passed with some warnings.

Anything else