Throw on BigInt division by zero

crates/perry-runtime/src/bigint.rs

@@ -13,6 +13,7 @@ pub const BIGINT_LIMBS: usize = 16;
 const BIGINT_BITS: usize = BIGINT_LIMBS * 64;
 
 const ZERO_LIMBS: [u64; BIGINT_LIMBS] = [0; BIGINT_LIMBS];
+const DIVISION_BY_ZERO_MESSAGE: &[u8] = b"Division by zero";
 
 /// Decode a 1024-bit two's-complement value into a host i64 if it fits.
 /// Layout: positive small → all upper limbs zero AND limb[0] high bit clear;
@@ -124,6 +125,16 @@ pub fn clean_bigint_ptr_mut(p: *mut BigIntHeader) -> *mut BigIntHeader {
     clean_bigint_ptr(p as *const BigIntHeader) as *mut BigIntHeader
 }
 
+#[cold]
+fn throw_bigint_division_by_zero() -> ! {
+    let msg = crate::string::js_string_from_bytes(
+        DIVISION_BY_ZERO_MESSAGE.as_ptr(),
+        DIVISION_BY_ZERO_MESSAGE.len() as u32,
+    );
+    let err = crate::error::js_rangeerror_new(msg);
+    crate::exception::js_throw(crate::value::js_nanbox_pointer(err as i64))
+}
+
 /// Create a BigInt from a u64 value
 #[no_mangle]
 pub extern "C" fn js_bigint_from_u64(value: u64) -> *mut BigIntHeader {
@@ -623,9 +634,8 @@ pub extern "C" fn js_bigint_div(
     let a_limbs = bigint_limbs_or_zero(a);
     let b_limbs = bigint_limbs_or_zero(b);
 
-    // Division by zero: return 0 instead of panicking (panic can't unwind in extern "C")
     if b_limbs == ZERO_LIMBS {
-        return bigint_alloc_with_limbs(ZERO_LIMBS);
+        throw_bigint_division_by_zero();
     }
 
     // Fast path: both fit in i64. Rust's `/` on i64 truncates toward
@@ -674,9 +684,8 @@ pub extern "C" fn js_bigint_mod(
     let a_limbs = bigint_limbs_or_zero(a);
     let b_limbs = bigint_limbs_or_zero(b);
 
-    // Division by zero: return 0 instead of panicking (panic can't unwind in extern "C")
     if b_limbs == ZERO_LIMBS {
-        return bigint_alloc_with_limbs(ZERO_LIMBS);
+        throw_bigint_division_by_zero();
     }
 
     // Fast path: both fit in i64. JavaScript's `%` returns the sign of

crates/perry-runtime/src/node_stream.rs

@@ -326,7 +326,7 @@ extern "C" fn ns_writable_final_callback_done(closure: *const ClosureHeader, err
         }
         return f64::from_bits(TAG_UNDEFINED);
     }
-    schedule_writable_finish(
+    schedule_writable_finish_then_transform_end(
         stream,
         if is_callable_value(callback) {
             Some(callback)
@@ -1192,7 +1192,7 @@ fn finish_stream(stream: f64, callback: Option<f64>) {
         set_pending_writable_finish_callback(stream, callback);
         return;
     }
-    schedule_writable_finish(stream, callback);
+    schedule_writable_finish_then_transform_end(stream, callback);
 }
 
 fn finish_stream_with_args(stream: f64, chunk: f64, encoding: f64, cb: f64) {

crates/perry-runtime/src/node_stream_readwrite.rs

@@ -719,6 +719,17 @@ pub(super) fn schedule_writable_finish(stream: f64, callback: Option<f64>) {
     crate::builtins::js_queue_microtask(closure as i64);
 }
 
+pub(super) fn schedule_writable_finish_then_transform_end(stream: f64, callback: Option<f64>) {
+    schedule_writable_finish(stream, callback);
+    if is_transform_stream(stream)
+        && !has_truthy_hidden(stream, hidden_writable_final_pending_key())
+        && (has_truthy_hidden(stream, hidden_finish_scheduled_key())
+            || has_truthy_hidden(stream, hidden_finish_emitted_key()))
+    {
+        schedule_readable_end(stream);
+    }
+}
+
 pub(super) fn set_pending_writable_finish_callback(stream: f64, callback: Option<f64>) {
     let value = callback.unwrap_or_else(|| f64::from_bits(TAG_UNDEFINED));
     set_hidden_value(stream, hidden_writable_pending_finish_callback_key(), value);
@@ -743,7 +754,7 @@ pub(super) fn schedule_pending_writable_finish_if_ready(stream: f64) {
         return;
     }
     let callback = take_pending_writable_finish_callback(stream);
-    schedule_writable_finish(stream, callback);
+    schedule_writable_finish_then_transform_end(stream, callback);
 }
 
 pub(super) fn emit_readable_end_once(stream: f64) {

test-parity/node-suite/bigint/arithmetic/division-by-zero.ts

@@ -0,0 +1,17 @@
+function probe(label: string, fn: () => bigint): void {
+  try {
+    console.log(label, "ok", String(fn()));
+  } catch (e) {
+    const err = e as Error;
+    console.log(label, "throw", err.name, err.message, e instanceof RangeError);
+  }
+}
+
+const zero = BigInt(0);
+
+probe("div literal zero", () => 1n / 0n);
+probe("mod literal zero", () => 1n % 0n);
+probe("div variable zero", () => 123n / zero);
+probe("mod variable zero", () => 123n % zero);
+probe("div nonzero", () => 7n / 2n);
+probe("mod nonzero", () => -7n % 2n);