test_runner: convert to uint during deserialization

Signed-off-by: Aviv Keller <me@aviv.sh>
PR-URL: #64706
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Author: avivkeller

lib/internal/test_runner/runner.js

@@ -466,12 +466,12 @@ class FileTest extends Test {
 while(bufferHead?.length>=kSerializedSizeHeader){
 // We call `readUInt32BE` manually here, because this is faster than first converting
 // it to a buffer and using `readUInt32BE` on that.
-constfullMessageSize=(
+constfullMessageSize=((
 bufferHead[kV8HeaderLength]<<24|
 bufferHead[kV8HeaderLength+1]<<16|
 bufferHead[kV8HeaderLength+2]<<8|
 bufferHead[kV8HeaderLength+3]
-)+kSerializedSizeHeader;
+)>>>0)+kSerializedSizeHeader;
 
 if(this.#rawBufferSize <fullMessageSize)break;
 

test/parallel/test-runner-v8-deserializer.mjs

@@ -30,12 +30,15 @@ defaultSerializer.writeHeader();
 constheaderLength=defaultSerializer.releaseBuffer().length;
 constheaderOnly=Buffer.from([0xff,0x0f]);
 constoversizedLengthHeader=Buffer.from([0xff,0x0f,0x7f,0xff,0xff,0xff]);
+constunsignedOversizedLengthHeader=Buffer.from([0xff,0x0f,0x80,0x00,0x00,0x00]);
 consttruncatedLengthHeader=Buffer.from([0xff,0x0f,0x00,0x01,0x00,0x00]);
 // Expected stdout for oversizedLengthHeader: first byte is emitted via
 // String.fromCharCode (byte-by-byte fallback in #drainRawBuffer), remaining
 // bytes go through the nonSerialized UTF-8 decode path in #processRawBuffer.
 constoversizedLengthStdout=String.fromCharCode(oversizedLengthHeader[0])+
 Buffer.from(oversizedLengthHeader.subarray(1)).toString('utf-8');
+constunsignedOversizedLengthStdout=String.fromCharCode(unsignedOversizedLengthHeader[0])+
+Buffer.from(unsignedOversizedLengthHeader.subarray(1)).toString('utf-8');
 
 functioncollectStdout(reported){
 returnreported
@@ -112,6 +115,12 @@ describe('v8 deserializer', common.mustCall(() => {
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
 
+it('should read an oversized length as an unsigned integer',async()=>{
+constreported=awaitcollectReported([unsignedOversizedLengthHeader]);
+assert(reported.every((event)=>event.type==='test:stdout'));
+assert.strictEqual(collectStdout(reported),unsignedOversizedLengthStdout);
+});
+
 it('should flush incomplete v8 frame as stdout and keep prior valid data',async()=>{
 // A valid non-serialized message followed by bytes that look like
 // a v8 header with a truncated/oversized length.