fix(stream): premature close when it is paused (#2416)

* Fix premature close

* Add test for premature close of the stream when it is paused

* Restore package-lock.json

Author: jansivans

lib/commands/query.js

@@ -30,7 +30,7 @@ class Query extends Command {
     this._receivedFieldsCount = 0;
     this._resultIndex = 0;
     this._localStream = null;
-    this._unpipeStream = function() {};
+    this._unpipeStream = function () { };
     this._streamFactory = options.infileStreamFactory;
     this._connection = null;
   }
@@ -155,7 +155,7 @@ class Query extends Command {
     const onPause = () => {
       this._localStream.pause();
     };
-    const onData = function(data) {
+    const onData = function (data) {
       const dataWithHeader = Buffer.allocUnsafe(data.length + 4);
       data.copy(dataWithHeader, 4);
       connection.writePacket(
@@ -227,7 +227,7 @@ class Query extends Command {
   }
 
   /* eslint no-unused-vars: ["error", { "argsIgnorePattern": "^_" }] */
-  row(packet, _connection) { 
+  row(packet, _connection) {
     if (packet.isEOF()) {
       const status = packet.eofStatusFlags();
       const moreResults = status & ServerStatus.SERVER_MORE_RESULTS_EXISTS;
@@ -279,11 +279,13 @@ class Query extends Command {
     });
     this.on('end', () => {
       stream.push(null); // pushing null, indicating EOF
-      setImmediate(() => stream.emit('close')); // notify readers that query has completed
     });
     this.on('fields', fields => {
       stream.emit('fields', fields); // replicate old emitter
     });
+    stream.on('end', () => {
+      stream.emit('close');
+    });
     return stream;
   }
 
@@ -302,7 +304,7 @@ class Query extends Command {
       Timers.clearTimeout(this.queryTimeout);
       this.queryTimeout = null;
     }
-    
+
     const err = new Error('Query inactivity timeout');
     err.errorno = 'PROTOCOL_SEQUENCE_TIMEOUT';
     err.code = 'PROTOCOL_SEQUENCE_TIMEOUT';

test/integration/connection/test-stream.js

@@ -8,6 +8,7 @@ let rows;
 const rows1 = [];
 const rows2 = [];
 const rows3 = [];
+const rows4 = [];
 
 connection.query(
   [
@@ -65,11 +66,17 @@ connection.execute('SELECT * FROM announcements', async (err, _rows) => {
   for await (const row of s3) {
     rows3.push(row);
   }
+  const s4 = connection.query('SELECT * FROM announcements').stream();
+  for await (const row of s4) {
+    await new Promise(resolve => setTimeout(resolve, 1000));
+    rows4.push(row);
+  }
 });
 
 process.on('exit', () => {
   assert.deepEqual(rows.length, 2);
   assert.deepEqual(rows, rows1);
   assert.deepEqual(rows, rows2);
   assert.deepEqual(rows, rows3);
+  assert.deepEqual(rows, rows4);
 });