stream: refactor writable _write

PR-URL: #50198 Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Matteo Collina <[email protected]>

Author: ronag

lib/internal/streams/writable.js

@@ -443,22 +443,21 @@ Writable.prototype.pipe = function(){
 function_write(stream,chunk,encoding,cb){
 conststate=stream._writableState;
 
-if(typeofencoding==='function'){
-cb=encoding;
-encoding=null;
-}
-
-if(!encoding)
-encoding=(state[kState]&kDefaultUTF8Encoding)!==0 ? 'utf8' : state[kDefaultEncodingValue];
-elseif(encoding!=='buffer'&&!Buffer.isEncoding(encoding))
-thrownewERR_UNKNOWN_ENCODING(encoding);
-
-if(cb==null||typeofcb!=='function')
+if(cb==null||typeofcb!=='function'){
 cb=nop;
+}
 
 if(chunk===null){
 thrownewERR_STREAM_NULL_VALUES();
-}elseif((state[kState]&kObjectMode)===0){
+}
+
+if((state[kState]&kObjectMode)===0){
+if(!encoding){
+encoding=(state[kState]&kDefaultUTF8Encoding)!==0 ? 'utf8' : state.defaultEncoding;
+}elseif(encoding!=='buffer'&&!Buffer.isEncoding(encoding)){
+thrownewERR_UNKNOWN_ENCODING(encoding);
+}
+
 if(typeofchunk==='string'){
 if((state[kState]&kDecodeStrings)!==0){
 chunk=Buffer.from(chunk,encoding);
@@ -487,11 +486,17 @@ function _write(stream, chunk, encoding, cb){
 errorOrDestroy(stream,err,true);
 returnerr;
 }
+
 state.pendingcb++;
 returnwriteOrBuffer(stream,state,chunk,encoding,cb);
 }
 
 Writable.prototype.write=function(chunk,encoding,cb){
+if(encoding!=null&&typeofencoding==='function'){
+cb=encoding;
+encoding=null;
+}
+
 return_write(this,chunk,encoding,cb)===true;
 };
 

test/parallel/test-stream-uint8array.js

@@ -38,7 +38,7 @@ const GHI = new Uint8Array([0x47, 0x48, 0x49]);
 assert(!(chunkinstanceofBuffer));
 assert(chunkinstanceofUint8Array);
 assert.strictEqual(chunk,ABC);
-assert.strictEqual(encoding,'utf8');
+assert.strictEqual(encoding,undefined);
 cb();
 })
 });