test: stream readableListening internal state

PR-URL: #9864 Refs: #8683 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Colin Ihrig <[email protected]>

Author: Italo A. Casas

test/parallel/test-stream-readableListening-state.js

@@ -0,0 +1,34 @@
+'use strict';
+
+constcommon=require('../common');
+constassert=require('assert');
+conststream=require('stream');
+
+constr=newstream.Readable({
+read: ()=>{}
+});
+
+// readableListening state should start in `false`.
+assert.strictEqual(r._readableState.readableListening,false);
+
+r.on('readable',common.mustCall(()=>{
+// Inside the readable event this state should be true.
+assert.strictEqual(r._readableState.readableListening,true);
+}));
+
+r.push(Buffer.from('Testing readableListening state'));
+
+constr2=newstream.Readable({
+read: ()=>{}
+});
+
+// readableListening state should start in `false`.
+assert.strictEqual(r2._readableState.readableListening,false);
+
+r2.on('data',common.mustCall((chunk)=>{
+// readableListening should be false because we don't have
+// a `readable` listener
+assert.strictEqual(r2._readableState.readableListening,false);
+}));
+
+r2.push(Buffer.from('Testing readableListening state'));