Remove selection title attribute if text is empty (#5589)

This fixes a bug that was introduced in Select2 4.0.0 and only
partially fixed in Select2 4.0.6-rc.0 where the `title` attribute
that is set on the selection container (or individual selections,
for a multiple select) is not cleared when the text/title of the
option is not set. In most cases, users no longer see this issue
because the `text` property of most data objects is set, so the
`title` attribute will always be cleared correctly. There was a bug
for cases where the `text` property was not set, or where the `text`
property was set to an empty string, that resulted in the `title`
attribute persisting with the incorrect value.

We have fixed this issue by always removing the `title` attribute
from the selection (or not adding it in the first place, for a
multiple select) when the `text` and `title` properties of the data
object are empty or not present.

This also adds in a series of tests to ensure the `title` attribute
is set properly in a variety of cases, building upon the ones that
already existed.

Fixes #3895

src/js/select2/selection/multiple.js

@@ -95,7 +95,12 @@ define([
       var formatted = this.display(selection, $selection);
 
       $selection.append(formatted);
-      $selection.attr('title', selection.title || selection.text);
+
+      var title = selection.title || selection.text;
+
+      if (title) {
+        $selection.attr('title', title);
+      }
 
       Utils.StoreData($selection[0], 'data', selection);
 

src/js/select2/selection/single.js

@@ -93,7 +93,14 @@ define([
     var formatted = this.display(selection, $rendered);
 
     $rendered.empty().append(formatted);
-    $rendered.attr('title', selection.title || selection.text);
+
+    var title = selection.title || selection.text;
+
+    if (title) {
+      $rendered.attr('title', title);
+    } else {
+      $rendered.removeAttr('title');
+    }
   };
 
   return SingleSelection;

tests/selection/multiple-tests.js

@@ -72,12 +72,119 @@ test('empty update clears the selection', function (assert) {
   var $rendered = $selection.find('.select2-selection__rendered');
 
   $rendered.text('testing');
-  $rendered.attr('title', 'testing');
 
   selection.update([]);
 
-  assert.equal($rendered.text(), '');
-  assert.equal($rendered.attr('title'), undefined);
+  assert.equal(
+    $rendered.text(),
+    '',
+    'There should have been nothing rendered'
+  );
+});
+
+test('empty update clears the selection title', function (assert) {
+  var selection = new MultipleSelection(
+    $('#qunit-fixture .multiple'),
+    options
+  );
+
+  var $selection = selection.render();
+
+  selection.update([]);
+
+  var $rendered = $selection.find('.select2-selection__rendered li');
+
+  assert.equal(
+    $rendered.attr('title'),
+    undefined,
+    'The title should be removed if nothing is rendered'
+  );
+});
+
+test('update sets the title to the data text', function (assert) {
+  var selection = new MultipleSelection(
+    $('#qunit-fixture .multiple'),
+    options
+  );
+
+  var $selection = selection.render();
+
+  selection.update([{
+    text: 'test'
+  }]);
+
+  var $rendered = $selection.find('.select2-selection__rendered li');
+
+  assert.equal(
+    $rendered.attr('title'),
+    'test',
+    'The title should have been set to the text'
+  );
+});
+
+test('update sets the title to the data title', function (assert) {
+  var selection = new MultipleSelection(
+    $('#qunit-fixture .multiple'),
+    options
+  );
+
+  var $selection = selection.render();
+
+  selection.update([{
+    text: 'test',
+    title: 'correct'
+  }]);
+
+  var $rendered = $selection.find('.select2-selection__rendered li');
+
+  assert.equal(
+    $rendered.attr('title'),
+    'correct',
+    'The title should have taken precedence over the text'
+  );
+});
+
+test('update should clear title for placeholder options', function (assert) {
+  var selection = new MultipleSelection(
+    $('#qunit-fixture .multiple'),
+    options
+  );
+
+  var $selection = selection.render();
+
+  selection.update([{
+    id: '',
+    text: ''
+  }]);
+
+  var $rendered = $selection.find('.select2-selection__rendered li');
+
+  assert.equal(
+    $rendered.attr('title'),
+    undefined,
+    'The title should be removed if a placeholder is rendered'
+  );
+});
+
+test('update should clear title for options without text', function (assert) {
+  var selection = new MultipleSelection(
+    $('#qunit-fixture .multiple'),
+    options
+  );
+
+  var $selection = selection.render();
+
+  selection.update([{
+    id: ''
+  }]);
+
+  var $rendered = $selection.find('.select2-selection__rendered li');
+
+  assert.equal(
+    $rendered.attr('title'),
+    undefined,
+    'The title should be removed if there is no text or title property'
+  );
 });
 
 test('escapeMarkup is being used', function (assert) {

tests/selection/single-tests.js

@@ -50,7 +50,7 @@ test('templateSelection can addClass', function (assert) {
   );
 
   var $container = selection.selectionContainer();
-  
+
   var out = selection.display({
     text: 'test'
   }, $container);
@@ -58,7 +58,7 @@ test('templateSelection can addClass', function (assert) {
   assert.ok(called);
 
   assert.equal(out, 'test');
-  
+
   assert.ok($container.hasClass('testclass'));
 });
 
@@ -72,12 +72,34 @@ test('empty update clears the selection', function (assert) {
   var $rendered = $selection.find('.select2-selection__rendered');
 
   $rendered.text('testing');
+
+  selection.update([]);
+
+  assert.equal(
+    $rendered.text(),
+    '',
+    'There should have been nothing rendered'
+  );
+});
+
+test('empty update clears the selection title', function (assert) {
+  var selection = new SingleSelection(
+    $('#qunit-fixture .single'),
+    options
+  );
+
+  var $selection = selection.render();
+  var $rendered = $selection.find('.select2-selection__rendered');
+
   $rendered.attr('title', 'testing');
 
   selection.update([]);
 
-  assert.equal($rendered.text(), '');
-  assert.equal($rendered.attr('title'), undefined);
+  assert.equal(
+    $rendered.attr('title'),
+    undefined,
+    'The title should be removed if nothing is rendered'
+  );
 });
 
 test('update renders the data text', function (assert) {
@@ -96,6 +118,92 @@ test('update renders the data text', function (assert) {
   assert.equal($rendered.text(), 'test');
 });
 
+test('update sets the title to the data text', function (assert) {
+  var selection = new SingleSelection(
+    $('#qunit-fixture .single'),
+    options
+  );
+
+  var $selection = selection.render();
+  var $rendered = $selection.find('.select2-selection__rendered');
+
+  selection.update([{
+    text: 'test'
+  }]);
+
+  assert.equal(
+    $rendered.attr('title'),
+    'test',
+    'The title should have been set to the text'
+  );
+});
+
+test('update sets the title to the data title', function (assert) {
+  var selection = new SingleSelection(
+    $('#qunit-fixture .single'),
+    options
+  );
+
+  var $selection = selection.render();
+  var $rendered = $selection.find('.select2-selection__rendered');
+
+  selection.update([{
+    text: 'test',
+    title: 'correct'
+  }]);
+
+  assert.equal(
+    $rendered.attr('title'),
+    'correct',
+    'The title should have taken precedence over the text'
+  );
+});
+
+test('update should clear title for placeholder options', function (assert) {
+  var selection = new SingleSelection(
+    $('#qunit-fixture .single'),
+    options
+  );
+
+  var $selection = selection.render();
+  var $rendered = $selection.find('.select2-selection__rendered');
+
+  $rendered.attr('title', 'testing');
+
+  selection.update([{
+    id: '',
+    text: ''
+  }]);
+
+  assert.equal(
+    $rendered.attr('title'),
+    undefined,
+    'The title should be removed if a placeholder is rendered'
+  );
+});
+
+test('update should clear title for options without text', function (assert) {
+  var selection = new SingleSelection(
+    $('#qunit-fixture .single'),
+    options
+  );
+
+  var $selection = selection.render();
+  var $rendered = $selection.find('.select2-selection__rendered');
+
+  $rendered.attr('title', 'testing');
+
+  selection.update([{
+    id: ''
+  }]);
+
+  assert.equal(
+    $rendered.attr('title'),
+    undefined,
+    'The title should be removed if there is no text or title property'
+  );
+});
+
 test('escapeMarkup is being used', function (assert) {
   var selection = new SingleSelection(
     $('#qunit-fixture .single'),