only verify when maximumSelectionCount is greater than 0 and add tests

dist/js/select2.amd.full.js

@@ -2867,7 +2867,8 @@ define('select2/data/maximumSelectionLength',[
 
       this.current(function (currentData) {
         var count = currentData != null ? currentData.length : 0;
-        if (count >= self.maximumSelectionLength) {
+        if (self.maximumSelectionLength > 0 &&
+          count >= self.maximumSelectionLength) {
           self.trigger('results:message', {
             message: 'maximumSelected',
             args: {

dist/js/select2.amd.js

@@ -2867,7 +2867,8 @@ define('select2/data/maximumSelectionLength',[
 
       this.current(function (currentData) {
         var count = currentData != null ? currentData.length : 0;
-        if (count >= self.maximumSelectionLength) {
+        if (self.maximumSelectionLength > 0 &&
+          count >= self.maximumSelectionLength) {
           self.trigger('results:message', {
             message: 'maximumSelected',
             args: {

dist/js/select2.full.js

@@ -12402,7 +12402,8 @@ define('select2/data/maximumSelectionLength',[
 
       this.current(function (currentData) {
         var count = currentData != null ? currentData.length : 0;
-        if (count >= self.maximumSelectionLength) {
+        if (self.maximumSelectionLength > 0 &&
+          count >= self.maximumSelectionLength) {
           self.trigger('results:message', {
             message: 'maximumSelected',
             args: {

dist/js/select2.js

@@ -3295,7 +3295,8 @@ define('select2/data/maximumSelectionLength',[
 
       this.current(function (currentData) {
         var count = currentData != null ? currentData.length : 0;
-        if (count >= self.maximumSelectionLength) {
+        if (self.maximumSelectionLength > 0 &&
+          count >= self.maximumSelectionLength) {
           self.trigger('results:message', {
             message: 'maximumSelected',
             args: {

src/js/select2/data/maximumSelectionLength.js

@@ -13,7 +13,8 @@ define([
 
       this.current(function (currentData) {
         var count = currentData != null ? currentData.length : 0;
-        if (count >= self.maximumSelectionLength) {
+        if (self.maximumSelectionLength > 0 &&
+          count >= self.maximumSelectionLength) {
           self.trigger('results:message', {
             message: 'maximumSelected',
             args: {

tests/data/maximumSelectionLength-tests.js

@@ -0,0 +1,199 @@
+module('Data adapters - Maximum selection length');
+
+var MaximumSelectionLength = require('select2/data/maximumSelectionLength');
+
+var $ = require('jquery');
+var Options = require('select2/options');
+var Utils = require('select2/utils');
+
+function StubData () {
+  this.called = false;
+  this.currentData = [];
+}
+
+StubData.prototype.current = function (callback) {
+  callback(this.currentData);
+};
+
+StubData.prototype.val = function (val) {
+  this.currentData.push(val);
+};
+
+StubData.prototype.query = function (params, callback) {
+  this.called = true;
+};
+
+var MaximumData = Utils.Decorate(StubData, MaximumSelectionLength);
+
+test('0 never displays the notice', function (assert) {
+  var zeroOptions = new Options({
+    maximumSelectionLength: 0
+  });
+
+  var data = new MaximumData(null, zeroOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, zeroOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.val('1');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, zeroOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.val('1');
+  data.val('2');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+});
+
+test('< 0 never displays the notice', function (assert) {
+  var negativeOptions = new Options({
+    maximumSelectionLength: -1
+  });
+
+  var data = new MaximumData(null, negativeOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, negativeOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.val('1');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, negativeOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.val('1');
+  data.val('2');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+});
+
+test('triggers when >= 1 selection' , function (assert) {
+  var maxOfOneOptions = new Options({
+    maximumSelectionLength: 1
+  });
+  var data = new MaximumData(null, maxOfOneOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, maxOfOneOptions);
+
+  data.trigger = function () {
+    assert.ok(true, 'The event should be triggered.');
+  };
+
+  data.val('1');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(!data.called);
+
+});
+
+test('triggers when >= 2 selections' , function (assert) {
+  var maxOfTwoOptions = new Options({
+    maximumSelectionLength: 2
+  });
+  var data = new MaximumData(null, maxOfTwoOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, maxOfTwoOptions);
+
+  data.trigger = function () {
+    assert.ok(false, 'No events should be triggered');
+  };
+
+  data.val('1');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(data.called);
+
+  data = new MaximumData(null, maxOfTwoOptions);
+
+  data.trigger = function () {
+    assert.ok(true, 'The event should be triggered.');
+  };
+
+  data.val('1');
+  data.val('2');
+
+  data.query({
+    term: ''
+  });
+
+  assert.ok(!data.called);
+
+});

tests/data/maximumSelectionLength.html

@@ -0,0 +1,19 @@
+<!doctype html>
+<html>
+  <head>
+    <link rel="stylesheet" href="../vendor/qunit-1.14.0.css" type="text/css" />
+    <link rel="stylesheet" href="../../dist/css/select2.css" type="text/css" />
+  </head>
+  <body>
+    <div id="qunit"></div>
+    <div id="qunit-fixture">
+    </div>
+
+    <script src="../vendor/qunit-1.14.0.js" type="text/javascript"></script>
+    <script src="../../vendor/almond-0.2.9.js" type="text/javascript"></script>
+    <script src="../../vendor/jquery-2.1.0.js" type="text/javascript"></script>
+    <script src="../../dist/js/select2.amd.js" type="text/javascript"></script>
+
+    <script src="maximumSelectionLength-tests.js" type="text/javascript"></script>
+  </body>
+</html>