stream: cleanup eos

PR-URL: #40998
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/streams/end-of-stream.js

@@ -49,14 +49,10 @@ function eos(stream, options, callback) {
 
   callback = once(callback);
 
-  const readable = options.readable ||
-    (options.readable !== false && isReadableNodeStream(stream));
-  const writable = options.writable ||
-    (options.writable !== false && isWritableNodeStream(stream));
+  const readable = options.readable ?? isReadableNodeStream(stream);
+  const writable = options.writable ?? isWritableNodeStream(stream);
 
-  if (isNodeStream(stream)) {
-    // Do nothing...
-  } else {
+  if (!isNodeStream(stream)) {
     // TODO: Webstreams.
     // TODO: Throw INVALID_ARG_TYPE.
   }
@@ -65,7 +61,9 @@ function eos(stream, options, callback) {
   const rState = stream._readableState;
 
   const onlegacyfinish = () => {
-    if (!stream.writable) onfinish();
+    if (!stream.writable) {
+      onfinish();
+    }
   };
 
   // TODO (ronag): Improve soft detection to include core modules and
@@ -83,10 +81,17 @@ function eos(stream, options, callback) {
     // Stream should not be destroyed here. If it is that
     // means that user space is doing something differently and
     // we cannot trust willEmitClose.
-    if (stream.destroyed) willEmitClose = false;
+    if (stream.destroyed) {
+      willEmitClose = false;
+    }
 
-    if (willEmitClose && (!stream.readable || readable)) return;
-    if (!readable || readableFinished) callback.call(stream);
+    if (willEmitClose && (!stream.readable || readable)) {
+      return;
+    }
+
+    if (!readable || readableFinished) {
+      callback.call(stream);
+    }
   };
 
   let readableFinished = isReadableFinished(stream, false);
@@ -95,10 +100,17 @@ function eos(stream, options, callback) {
     // Stream should not be destroyed here. If it is that
     // means that user space is doing something differently and
     // we cannot trust willEmitClose.
-    if (stream.destroyed) willEmitClose = false;
+    if (stream.destroyed) {
+      willEmitClose = false;
+    }
 
-    if (willEmitClose && (!stream.writable || writable)) return;
-    if (!writable || writableFinished) callback.call(stream);
+    if (willEmitClose && (!stream.writable || writable)) {
+      return;
+    }
+
+    if (!writable || writableFinished) {
+      callback.call(stream);
+    }
   };
 
   const onerror = (err) => {
@@ -139,8 +151,11 @@ function eos(stream, options, callback) {
     if (!willEmitClose) {
       stream.on('abort', onclose);
     }
-    if (stream.req) onrequest();
-    else stream.on('request', onrequest);
+    if (stream.req) {
+      onrequest();
+    } else {
+      stream.on('request', onrequest);
+    }
   } else if (writable && !wState) { // legacy streams
     stream.on('end', onlegacyfinish);
     stream.on('close', onlegacyfinish);
@@ -153,7 +168,9 @@ function eos(stream, options, callback) {
 
   stream.on('end', onend);
   stream.on('finish', onfinish);
-  if (options.error !== false) stream.on('error', onerror);
+  if (options.error !== false) {
+    stream.on('error', onerror);
+  }
   stream.on('close', onclose);
 
   if (closed) {