twbs · ChrisMBarr · Mar 21, 2016 · Mar 21, 2016
diff --git a/src/bootlint.js b/src/bootlint.js
@@ -586,6 +586,29 @@ var LocationIndex = _location.LocationIndex;
             reporter('Found one or more `<input>`s missing a `type` attribute.', inputsMissingTypeAttr);
         }
     });
+    addLinter('W018', function lintUselessFullColumns($, reporter) {
+        var selector = SCREENS.map(function (size) {
+            return '.col-' + size + '-' + NUM_COLS;
+        }).join(',');
+        var fullRows = $(selector);
+        if (fullRows.length) {
+            var fullColRegex = new RegExp('^col-(' + SCREENS.join('|') + ')-' + NUM_COLS + '$');
+            fullRows.each(function (_index, row) {
+                var $row = $(row);
+                var gridClasses = $row.attr('class').match(COL_REGEX_G);
+                var fullWidthColCount = 0;
+                for (var i = 0; i < gridClasses.length; i++) {
+                    if (fullColRegex.test(gridClasses[i])) {
+                        fullWidthColCount++;
+                    }
+                }
+                if (fullWidthColCount === gridClasses.length) {
+                    //The ONLY grid classes found here were full column classes.
+                    reporter('`.col-*-' + NUM_COLS + '` classes used alone are not useful. This element does not need to be in a row/column since it will render the same way without using the grid here at all', $row);
+                }
+            });
+        }
+    });
 
     addLinter('E001', (function () {
         var MISSING_DOCTYPE = 'Document is missing a DOCTYPE declaration';

diff --git a/test/bootlint_test.js b/test/bootlint_test.js
@@ -977,5 +977,17 @@ exports.bootlint = {
             'should complain about a `.pull-right/.pull-left` classes on `.row` AND manual `style="float:left;"/style="float:right;"` on a `.row`'
         );
         test.done();
+    },
+    '.col-*-12 columns by themselves are not useful': function (test) {
+        test.expect(1);
+        test.deepEqual(lintHtml(utf8Fixture('grid/col-no-full-width.html')),
+            [
+                'Since grid classes apply to devices with screen widths greater than or equal to the breakpoint sizes (unless overridden by grid classes targeting larger screens), `class="col-xs-12 col-sm-12"` is redundant and can be simplified to `class="col-xs-12"`',
+                '`.col-*-12` classes used alone are not useful. This element does not need to be in a row/column since it will render the same way without using the grid here at all',
+                '`.col-*-12` classes used alone are not useful. This element does not need to be in a row/column since it will render the same way without using the grid here at all'
+            ],
+            'should complain about a `.col-*-12` class used with no other grid classes AND about multiple `.col-*-12` classes appearing with no other grid classes'
+        );
+        test.done();
     }
 };
diff --git a/test/fixtures/alert-dismiss-close/close-preceded-by-elem.html b/test/fixtures/alert-dismiss-close/close-preceded-by-elem.html
@@ -19,7 +19,7 @@
     <body>
         <div class="container">
             <div class="row">
-                <div class="col-md-12">
+                <div class="col-md-8">
                         <div class="alert alert-danger alert-dismissible">
                             <ul>
                                 <li>This list should come after the button</li>

diff --git a/test/fixtures/alert-dismiss-close/close-preceded-by-nothing.html b/test/fixtures/alert-dismiss-close/close-preceded-by-nothing.html
@@ -19,7 +19,7 @@
     <body>
         <div class="container">
             <div class="row">
-                <div class="col-md-12">
+                <div class="col-md-8">
                     <div class="alert alert-danger alert-dismissible"><button type="button" class="close">Close</button>This text should be after the button.</div>
                 </div>
             </div>

diff --git a/test/fixtures/alert-dismiss-close/close-preceded-by-text.html b/test/fixtures/alert-dismiss-close/close-preceded-by-text.html
@@ -19,7 +19,7 @@
     <body>
         <div class="container">
             <div class="row">
-                <div class="col-md-12">
+                <div class="col-md-8">
                     <div class="alert alert-danger alert-dismissible">
                         This text should be after the button.
                         <button type="button" class="close">Close</button>

diff --git a/test/fixtures/alert-dismiss-close/missing-alert-dismissible.html b/test/fixtures/alert-dismiss-close/missing-alert-dismissible.html
@@ -19,7 +19,7 @@
     <body>
         <div class="container">
             <div class="row">
-                <div class="col-md-12">
+                <div class="col-md-8">
                         <div class="alert alert-danger">
                             <button type="button" class="close" data-dismiss="alert">
                                 <span aria-hidden="true">&times;</span><span class="sr-only">Close</span>

diff --git a/test/fixtures/alert-dismiss-close/valid.html b/test/fixtures/alert-dismiss-close/valid.html
@@ -19,7 +19,7 @@
     <body>
         <div class="container">
             <div class="row">
-                <div class="col-md-12">
+                <div class="col-md-8">
                         <div class="alert alert-danger alert-dismissible">
                             <button type="button" class="close" data-dismiss="alert">
                                 <span aria-hidden="true">&times;</span><span class="sr-only">Close</span>

diff --git a/test/fixtures/containers/columns.html b/test/fixtures/containers/columns.html
@@ -21,7 +21,7 @@
             <div class="row">
                 <div class="col-xs-6">
                     <div class="row">
-                        <div class="col-xs-12">
+                        <div class="col-xs-6">
                             We can nest rows within columns.
                         </div>
                     </div>

diff --git a/test/fixtures/grid/col-no-full-width.html b/test/fixtures/grid/col-no-full-width.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="utf-8" />
+        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+        <meta name="viewport" content="width=device-width, initial-scale=1" />
+        <title>Test</title>
+        <!--[if lt IE 9]>
+            <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
+            <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
+        <![endif]-->
+        <script src="../../lib/jquery.min.js"></script>
+
+        <link rel="stylesheet" href="../../lib/qunit.css">
+        <script src="../../lib/qunit.js"></script>
+        <script src="../../../dist/browser/bootlint.js"></script>
+        <script src="../generic-qunit.js"></script>
+    </head>
+    <body>
+        <div class="container">
+            <div class="row">
+                <div class="col-xs-12">Useless</div>
+            </div>
+
+            <div class="row">
+                <div class="col-xs-12 col-sm-12">Useless</div>
+            </div>
+
+            <div class="row">
+                <div class="col-xs-12 col-sm-6 col-md-12">This is fine</div>
+            </div>
+
+            <div class="row">
+                <div class="col-sm-6 col-md-12">This is fine</div>
+            </div>
+        </div>
+
+        <div id="qunit"></div>
+        <ol id="bootlint">
+            <li data-lint='Since grid classes apply to devices with screen widths greater than or equal to the breakpoint sizes (unless overridden by grid classes targeting larger screens), `class="col-xs-12 col-sm-12"` is redundant and can be simplified to `class="col-xs-12"`'></li>
+            <li data-lint="`.col-*-12` classes used alone are not useful. This element does not need to be in a row/column since it will render the same way without using the grid here at all"></li>
+            <li data-lint="`.col-*-12` classes used alone are not useful. This element does not need to be in a row/column since it will render the same way without using the grid here at all"></li>
+        </ol>
+    </body>
+</html>
diff --git a/test/fixtures/input-group/mixed-with-grid-col.html b/test/fixtures/input-group/mixed-with-grid-col.html
@@ -19,7 +19,7 @@
     <body>
         <div class="container">
             <div class="row">
-                <div class="input-group col-sm-12">
+                <div class="input-group col-sm-8">
                     <span class="input-group-addon">@</span>
                     <input type="text" class="form-control" placeholder="Username">
                 </div>