Merge pull request #605 from gyoshev/feature/no-trailing-whitespace-rule

New rule: no-trailing-whitespace

docs/rules/no-trailing-whitespace.md

@@ -0,0 +1,21 @@
+# No Trailing Whitespace
+
+Rule `no-trailing-whitespace` will enforce that trailing whitespace is not allowed.
+
+## Examples
+
+When enabled, the following are disallowed (\s denotes spaces or tabs):
+
+```scss
+.foo {\s
+  margin: 1.5rem;
+}
+
+.foo {
+  margin: .5rem;\s
+}
+
+.foo {
+  margin: .4rem;
+}\s
+```

lib/config/sass-lint.yml

@@ -30,6 +30,7 @@ rules:
   no-mergeable-selectors: 1
   no-misspelled-properties: 1
   no-qualifying-elements: 1
+  no-trailing-whitespace: 1
   no-trailing-zero: 1
   no-transition-all: 1
   no-url-protocols: 1

lib/rules/no-trailing-whitespace.js

@@ -0,0 +1,37 @@
+'use strict';
+
+var helpers = require('../helpers');
+
+module.exports = {
+  'name': 'no-trailing-whitespace',
+  'defaults': {},
+  'detect': function (ast, parser) {
+    var result = [];
+    var trailing = (/( |\t)+\n/);
+
+    ast.traverseByType('space', function (space, i, parent) {
+      var content = space.content;
+      var nextIndex = i + 1;
+      var next = parent.content[nextIndex];
+
+      while (next && (next.is('space') || next.is('declarationDelimeter'))) {
+        content += next.content;
+        nextIndex++;
+        next = parent.content[nextIndex];
+      }
+
+      if (trailing.test(content)) {
+        result = helpers.addUnique(result, {
+          'ruleId': parser.rule.name,
+          'severity': parser.severity,
+          'line': space.start.line,
+          'column': space.start.column,
+          'message': 'No trailing whitespace allowed'
+        });
+      }
+    });
+
+    return result;
+  }
+};
+

tests/rules/no-trailing-whitespace.js

@@ -0,0 +1,35 @@
+'use strict';
+
+var lint = require('./_lint');
+
+//////////////////////////////
+// SCSS syntax tests
+//////////////////////////////
+describe('no trailing whitespace - scss', function () {
+  var file = lint.file('no-trailing-whitespace.scss');
+
+  it('enforce', function (done) {
+    lint.test(file, {
+      'no-trailing-whitespace': 1
+    }, function (data) {
+      lint.assert.equal(5, data.warningCount);
+      done();
+    });
+  });
+});
+
+//////////////////////////////
+// Sass syntax tests
+//////////////////////////////
+describe('no trailing whitespace - sass', function () {
+  var file = lint.file('no-trailing-whitespace.sass');
+
+  it('enforce', function (done) {
+    lint.test(file, {
+      'no-trailing-whitespace': 1
+    }, function (data) {
+      lint.assert.equal(5, data.warningCount);
+      done();
+    });
+  });
+});

tests/sass/no-trailing-whitespace.sass

@@ -0,0 +1,24 @@
+.foo
+  margin: 1.5rem;
+
+// Two trailing spaces after selector
+.bar  
+  margin: 1.5rem;
+
+// Two trailing spaces after property
+.baz
+  margin: 1.5rem;  
+
+// Two trailing spaces between rules
+.qux
+  margin: 1.5rem;
+
+
+// Trailing tab after selector
+.cat	
+  margin: 1.5rem;
+
+// Trailing tab after property
+.dog
+  margin: 1.5rem;	
+

tests/sass/no-trailing-whitespace.scss

@@ -0,0 +1,29 @@
+.foo {
+  margin: 1.5rem;
+}
+
+// Two trailing spaces after selector
+.bar {  
+  margin: 1.5rem;
+}
+
+// Two trailing spaces after property
+.baz {
+  margin: 1.5rem;  
+}
+
+// Two trailing spaces after rule
+.qux {
+  margin: 1.5rem;
+}  
+
+// Trailing tab after selector
+.cat {	
+  margin: 1.5rem;
+}
+
+// Trailing tab after property
+.dog {
+  margin: 1.5rem;	
+}
+