Requiring native bindings polutes 'global' (#984)

There was some nasty global-ish variable reference updating happening when the native module 'initializes' after its require with `require('pg').native`

This fixes the issue by making sure both `require('pg')` and `require('pg').native` each initialize their own context in isolation and no weird global-ish references are used & subsequently stomped on.

lib/index.js

@@ -8,9 +8,9 @@ var Connection = require('./connection');
 var PG = function(clientConstructor) {
   EventEmitter.call(this);
   this.defaults = defaults;
-  this.Client = pool.Client = clientConstructor;
+  this.Client = clientConstructor;
   this.Query = this.Client.Query;
-  this.pools = pool;
+  this.pools = pool(clientConstructor);
   this.Connection = Connection;
   this.types = require('pg-types');
 };

lib/pool.js

@@ -3,11 +3,12 @@ var EventEmitter = require('events').EventEmitter;
 var defaults = require('./defaults');
 var genericPool = require('generic-pool');
 
+
+module.exports = function(Client) {
   var pools = {
     //dictionary of all key:pool pairs
     all: {},
     //reference to the client constructor - can override in tests or for require('pg').native
-  Client: require('./client'),
     getOrCreate: function(clientConfig) {
       clientConfig = clientConfig || {};
       var name = JSON.stringify(clientConfig);
@@ -22,7 +23,7 @@ var pools = {
         reapIntervalMillis: clientConfig.reapIntervalMillis || defaults.reapIntervalMillis,
         log: clientConfig.poolLog || defaults.poolLog,
         create: function(cb) {
-        var client = new pools.Client(clientConfig);
+          var client = new Client(clientConfig);
           // Ignore errors on pooled clients until they are connected.
           client.on('error', Function.prototype);
           client.connect(function(err) {
@@ -92,4 +93,5 @@ var pools = {
     }
   };
 
-module.exports = pools;
+  return pools;
+};

test/integration/gh-issues/981-tests.js

@@ -0,0 +1,27 @@
+var helper = require(__dirname + '/../test-helper');
+
+//native bindings are only installed for native tests
+if(!helper.args.native) {
+  return;
+}
+
+var assert = require('assert')
+var pg = require('../../../lib')
+var native = require('../../../lib').native
+
+var JsClient = require('../../../lib/client')
+var NativeClient = require('../../../lib/native')
+
+assert(pg.Client === JsClient);
+assert(native.Client === NativeClient);
+
+pg.connect(function(err, client, done) {
+  assert(client instanceof JsClient);
+  client.end();
+
+  native.connect(function(err, client, done) {
+    assert(client instanceof NativeClient);
+    client.end();
+  });
+});
+

test/unit/pool/basic-tests.js

@@ -2,8 +2,8 @@ var util = require('util');
 var EventEmitter = require('events').EventEmitter;
 
 var libDir = __dirname + '/../../../lib';
+var poolsFactory = require(libDir + '/pool')
 var defaults = require(libDir + '/defaults');
-var pools = require(libDir + '/pool');
 var poolId = 0;
 
 require(__dirname + '/../../test-helper');
@@ -21,6 +21,7 @@ FakeClient.prototype.connect = function(cb) {
 FakeClient.prototype.end = function() {
   this.endCalled = true;
 }
+var pools = poolsFactory(FakeClient);
 
 //Hangs the event loop until 'end' is called on client
 var HangingClient = function(config) {
@@ -41,8 +42,6 @@ HangingClient.prototype.end = function() {
   clearInterval(this.intervalId);
 }
 
-pools.Client = FakeClient;
-
 test('no pools exist', function() {
   assert.empty(Object.keys(pools.all));
 });
@@ -115,7 +114,7 @@ test('on client error, client is removed from pool', function() {
 });
 
 test('pool with connection error on connection', function() {
-  pools.Client = function() {
+  var errorPools = poolsFactory(function() {
     return {
       connect: function(cb) {
         process.nextTick(function() {
@@ -124,9 +123,10 @@ test('pool with connection error on connection', function() {
       },
       on: Function.prototype
     };
-  };
+  })
+
   test('two parameters', function() {
-    var p = pools.getOrCreate(poolId++);
+    var p = errorPools.getOrCreate(poolId++);
     p.connect(assert.calls(function(err, client) {
       assert.ok(err);
       assert.equal(client, null);
@@ -136,7 +136,7 @@ test('pool with connection error on connection', function() {
     }));
   });
   test('three parameters', function() {
-    var p = pools.getOrCreate(poolId++);
+    var p = errorPools.getOrCreate(poolId++);
     var tid = setTimeout(function() {
       assert.fail('Did not call connect callback');
     }, 100);
@@ -155,7 +155,6 @@ test('pool with connection error on connection', function() {
 
 test('returnning an error to done()', function() {
   var p = pools.getOrCreate(poolId++);
-  pools.Client = FakeClient;
   p.connect(function(err, client, done) {
     assert.equal(err, null);
     assert(client);

test/unit/pool/timeout-tests.js

@@ -3,7 +3,7 @@ var EventEmitter = require('events').EventEmitter;
 
 var libDir = __dirname + '/../../../lib';
 var defaults = require(libDir + '/defaults');
-var pools = require(libDir + '/pool');
+var poolsFactory = require(libDir + '/pool');
 var poolId = 0;
 
 require(__dirname + '/../../test-helper');
@@ -25,8 +25,9 @@ FakeClient.prototype.end = function() {
 defaults.poolIdleTimeout = 10;
 defaults.reapIntervalMillis = 10;
 
+var pools = poolsFactory(FakeClient)
+
 test('client times out from idle', function() {
-  pools.Client = FakeClient;
   var p = pools.getOrCreate(poolId++);
   p.connect(function(err, client, done) {
     done();