Queued query errors

lib/client.js

@@ -36,6 +36,7 @@ var Client = function (config) {
   this._connecting = false
   this._connected = false
   this._connectionError = false
+  this._queryable = true
 
   this.connection = c.connection || new Connection({
     stream: c.stream,
@@ -52,16 +53,31 @@ var Client = function (config) {
 
 util.inherits(Client, EventEmitter)
 
-Client.prototype.connect = function (callback) {
+Client.prototype._errorAllQueries = function (err) {
+  const enqueueError = (query) => {
+    process.nextTick(() => {
+      query.handleError(err, this.connection)
+    })
+  }
+
+  if (this.activeQuery) {
+    enqueueError(this.activeQuery)
+    this.activeQuery = null
+  }
+
+  this.queryQueue.forEach(enqueueError)
+  this.queryQueue.length = 0
+}
+
+Client.prototype._connect = function (callback) {
   var self = this
   var con = this.connection
   if (this._connecting || this._connected) {
     const err = new Error('Client has already been connected. You cannot reuse a client.')
-    if (callback) {
+    process.nextTick(() => {
       callback(err)
-      return undefined
-    }
-    return Promise.reject(err)
+    })
+    return
   }
   this._connecting = true
 
@@ -126,15 +142,25 @@ Client.prototype.connect = function (callback) {
   }
 
   const connectedErrorHandler = (err) => {
-    if (this.activeQuery) {
-      var activeQuery = self.activeQuery
-      this.activeQuery = null
-      return activeQuery.handleError(err, con)
-    }
+    this._queryable = false
+    this._errorAllQueries(err)
     this.emit('error', err)
   }
 
+  const connectedErrorMessageHandler = (msg) => {
+    const activeQuery = this.activeQuery
+
+    if (!activeQuery) {
+      connectedErrorHandler(msg)
+      return
+    }
+
+    this.activeQuery = null
+    activeQuery.handleError(msg, con)
+  }
+
   con.on('error', connectingErrorHandler)
+  con.on('errorMessage', connectingErrorHandler)
 
   // hook up query handling events to connection
   // after the connection initially becomes ready for queries
@@ -143,7 +169,9 @@ Client.prototype.connect = function (callback) {
     self._connected = true
     self._attachListeners(con)
     con.removeListener('error', connectingErrorHandler)
+    con.removeListener('errorMessage', connectingErrorHandler)
     con.on('error', connectedErrorHandler)
+    con.on('errorMessage', connectedErrorMessageHandler)
 
     // process possible callback argument to Client#connect
     if (callback) {
@@ -166,43 +194,53 @@ Client.prototype.connect = function (callback) {
   })
 
   con.once('end', () => {
-    if (this.activeQuery) {
-      var disconnectError = new Error('Connection terminated')
-      this.activeQuery.handleError(disconnectError, con)
-      this.activeQuery = null
-    }
+    const error = this._ending
+      ? new Error('Connection terminated')
+      : new Error('Connection terminated unexpectedly')
+
+    this._errorAllQueries(error)
+
     if (!this._ending) {
       // if the connection is ended without us calling .end()
       // on this client then we have an unexpected disconnection
       // treat this as an error unless we've already emitted an error
       // during connection.
-      const error = new Error('Connection terminated unexpectedly')
       if (this._connecting && !this._connectionError) {
         if (callback) {
           callback(error)
         } else {
-          this.emit('error', error)
+          connectedErrorHandler(error)
         }
       } else if (!this._connectionError) {
-        this.emit('error', error)
+        connectedErrorHandler(error)
       }
     }
-    this.emit('end')
+
+    process.nextTick(() => {
+      this.emit('end')
+    })
   })
 
   con.on('notice', function (msg) {
     self.emit('notice', msg)
   })
+}
 
-  if (!callback) {
-    return new global.Promise((resolve, reject) => {
-      this.once('error', reject)
-      this.once('connect', () => {
-        this.removeListener('error', reject)
+Client.prototype.connect = function (callback) {
+  if (callback) {
+    this._connect(callback)
+    return
+  }
+
+  return new Promise((resolve, reject) => {
+    this._connect((error) => {
+      if (error) {
+        reject(error)
+      } else {
         resolve()
-      })
+      }
     })
-  }
+  })
 }
 
 Client.prototype._attachListeners = function (con) {
@@ -353,7 +391,15 @@ Client.prototype._pulseQueryQueue = function () {
     if (this.activeQuery) {
       this.readyForQuery = false
       this.hasExecuted = true
-      this.activeQuery.submit(this.connection)
+
+      const queryError = this.activeQuery.submit(this.connection)
+      if (queryError) {
+        process.nextTick(() => {
+          this.activeQuery.handleError(queryError, this.connection)
+          this.readyForQuery = true
+          this._pulseQueryQueue()
+        })
+      }
     } else if (this.hasExecuted) {
       this.activeQuery = null
       this.emit('drain')
@@ -389,25 +435,40 @@ Client.prototype.query = function (config, values, callback) {
     query._result._getTypeParser = this._types.getTypeParser.bind(this._types)
   }
 
+  if (!this._queryable) {
+    process.nextTick(() => {
+      query.handleError(new Error('Client has encountered a connection error and is not queryable'), this.connection)
+    })
+    return result
+  }
+
+  if (this._ending) {
+    process.nextTick(() => {
+      query.handleError(new Error('Client was closed and is not queryable'), this.connection)
+    })
+    return result
+  }
+
   this.queryQueue.push(query)
   this._pulseQueryQueue()
   return result
 }
 
 Client.prototype.end = function (cb) {
   this._ending = true
+
   if (this.activeQuery) {
     // if we have an active query we need to force a disconnect
     // on the socket - otherwise a hung query could block end forever
-    this.connection.stream.destroy(new Error('Connection terminated by user'))
-    return cb ? cb() : Promise.resolve()
+    this.connection.stream.destroy()
+  } else {
+    this.connection.end()
   }
+
   if (cb) {
-    this.connection.end()
     this.connection.once('end', cb)
   } else {
-    return new global.Promise((resolve, reject) => {
-      this.connection.end()
+    return new Promise((resolve) => {
       this.connection.once('end', resolve)
     })
   }

lib/connection.js

@@ -117,10 +117,11 @@ Connection.prototype.attachListeners = function (stream) {
     var packet = self._reader.read()
     while (packet) {
       var msg = self.parseMessage(packet)
+      var eventName = msg.name === 'error' ? 'errorMessage' : msg.name
       if (self._emitMessage) {
         self.emit('message', msg)
       }
-      self.emit(msg.name, msg)
+      self.emit(eventName, msg)
       packet = self._reader.read()
     }
   })