Good error handling and test running

Author: felixge

Makefile

@@ -0,0 +1,4 @@
+test:
+	node test/run.js
+
+.PHONY: test

lib/Connection.js

@@ -1,9 +1,14 @@
-var Net      = require('net');
-var Config   = require('./Config');
-var Protocol = require('./protocol/Protocol');
+var Net          = require('net');
+var Config       = require('./Config');
+var Protocol     = require('./protocol/Protocol');
+var EventEmitter = require('events').EventEmitter;
+var Util         = require('util');
 
 module.exports = Connection;
+Util.inherits(Connection, EventEmitter);
 function Connection(options) {
+  EventEmitter.call(this);
+
   this.config = new Config(options.config);
 
   this._socket   = options.socket;
@@ -21,6 +26,7 @@ Connection.prototype.connect = function(cb) {
   this._protocol.handshake(this.config, cb);
 
   this._socket.on('error', this._handleNetworkError.bind(this));
+  this._protocol.on('error', this._handleProtocolError.bind(this));
 };
 
 Connection.prototype.query = function(sql, cb) {
@@ -36,3 +42,7 @@ Connection.prototype.end = function() {
 Connection.prototype._handleNetworkError = function(err) {
   this._protocol.fatalError(err);
 };
+
+Connection.prototype._handleProtocolError = function(err) {
+  this.emit('error', err);
+};

lib/protocol/Protocol.js

@@ -93,8 +93,8 @@ Protocol.prototype._executeSequence = function(sequence) {
   var self = this;
 
   sequence
-    .on('fatalError', function(err) {
-      self.fatalError(err);
+    .on('error', function(err) {
+      self._handleSequenceError(sequence, err);
     })
     .on('data', function(buffer) {
       self.emit('data', buffer);
@@ -115,14 +115,34 @@ Protocol.prototype._dequeue = function() {
   }
 };
 
+Protocol.prototype._handleSequenceError = function(sequence, err) {
+  var bubbleUp = (sequence.hasCallback())
+    ? false
+    : err.fatal && !this._hasPendingCallbacks();
+
+  if (bubbleUp) {
+    this.emit('error', err);
+  }
+
+  if (err.fatal) {
+    this.fatalError(err);
+  }
+};
+
+Protocol.prototype._hasPendingCallbacks = function() {
+  return this._queue.some(function(sequence) {
+    return sequence.hasCallback();
+  });
+};
+
 Protocol.prototype.fatalError = function(err) {
   err.fatal = true;
 
   var pendingSequences = this._queue;
   this._queue = [];
 
   pendingSequences.forEach(function(sequence) {
-    sequence.end(err);
+    sequence.invokeCallback(err);
   });
 };
 

lib/protocol/sequences/Sequence.js

@@ -21,6 +21,10 @@ Sequence.determinePacket = function(byte) {
   }
 };
 
+Sequence.prototype.hasCallback = function() {
+  return Boolean(this._callback);
+};
+
 Sequence.packetToError = function(packet) {
   var err = new Error(packet.message);
   err.code = ErrorConstants[packet.errno] || 'UNKNOWN_CODE_PLEASE_REPORT';
@@ -51,18 +55,21 @@ Sequence.prototype._incrementNextPacketNumber = function() {
   this._nextPacketNumber = (this._nextPacketNumber + 1) % 256;
 };
 
+Sequence.prototype.invokeCallback = function() {
+  if (this._callback) {
+    this._callback.apply(this, arguments);
+  }
+};
+
 Sequence.prototype.end = function(err) {
   if (this._callback) {
     this._callback.apply(this, arguments);
-  } else if (err) {
-    this.emit('error', err);
   }
 
   this.emit('end');
 
-  if (err.fatal) {
-    this.emit('fatalError', err);
-    return;
+  if (err) {
+    this.emit('error', err);
   }
 };
 

test/integration/test-fatal-auth-error-without-handlers.js

@@ -0,0 +1,16 @@
+var common     = require('../common');
+var connection = common.createConnection({password: common.bogusPassword});
+var assert     = require('assert');
+
+connection.connect();
+connection.query('SELECT 1');
+
+var err;
+connection.on('error', function(_err) {
+  err = _err;
+});
+
+process.on('exit', function() {
+  assert.equal(err.code, 'ER_ACCESS_DENIED_ERROR');
+  assert.equal(err.fatal, true);
+});

test/run.js

@@ -0,0 +1 @@
+require('urun')(__dirname)