stream: simplify Writable.end()

Simplifies Writable.end() by inlining and de-duplicating code. PR-URL: #32882 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Gerhard Stöbich <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: Matteo Collina <[email protected]>

Author: ronag

lib/_stream_writable.js

@@ -588,21 +588,26 @@ Writable.prototype.end = function(chunk, encoding, cb){
 this.uncork();
 }
 
-if(typeofcb!=='function')
-cb=nop;
-
 // This is forgiving in terms of unnecessary calls to end() and can hide
 // logic errors. However, usually such errors are harmless and causing a
 // hard error can be disproportionately destructive. It is not always
 // trivial for the user to determine whether end() needs to be called or not.
+leterr;
 if(!state.errored&&!state.ending){
-endWritable(this,state,cb);
+state.ending=true;
+finishMaybe(this,state,true);
+state.ended=true;
 }elseif(state.finished){
-process.nextTick(cb,newERR_STREAM_ALREADY_FINISHED('end'));
+err=newERR_STREAM_ALREADY_FINISHED('end');
 }elseif(state.destroyed){
-process.nextTick(cb,newERR_STREAM_DESTROYED('end'));
-}elseif(cb!==nop){
-onFinished(this,state,cb);
+err=newERR_STREAM_DESTROYED('end');
+}
+
+if(typeofcb==='function'){
+if(err||state.finished)
+process.nextTick(cb,err);
+else
+onFinished(this,state,cb);
 }
 
 returnthis;
@@ -683,18 +688,6 @@ function finish(stream, state){
 }
 }
 
-functionendWritable(stream,state,cb){
-state.ending=true;
-finishMaybe(stream,state,true);
-if(cb!==nop){
-if(state.finished)
-process.nextTick(cb);
-else
-onFinished(stream,state,cb);
-}
-state.ended=true;
-}
-
 functiononCorkedFinish(corkReq,state,err){
 letentry=corkReq.entry;
 corkReq.entry=null;