Fix #90 - whitespace between mixin and !important is optional

lib/less-parser.js

@@ -114,9 +114,9 @@ export default class LessParser extends Parser {
       // eslint-disable-next-line
       delete this.current.nodes;
 
-      if (node.selector.indexOf('!important') >= 0) {
+      if (/!important/i.test(node.selector)) {
         node.important = true;
-        node.selector = node.selector.replace(/\s!important/, '');
+        node.selector = node.selector.replace(/\s*!important/i, '');
       }
 
       // rules don't have trailing semicolons in vanilla css, so they get

test/parser/mixins.spec.js

@@ -136,6 +136,28 @@ describe('Parser', () => {
         expect(root.first.important).to.eql(true);
       });
 
+      it('parses nested mixins with `!important` - insensitive to casing', () => {
+        const code = `
+                    .foo() !IMPoRTant;
+                `;
+
+        const root = parse(code);
+
+        expect(root.first.selector).to.eql('.foo()');
+        expect(root.first.important).to.eql(true);
+      });
+
+      it('parses nested mixins with `!important` - appended without whitespace', () => {
+        const code = `
+                    .foo()!important;
+                `;
+
+        const root = parse(code);
+
+        expect(root.first.selector).to.eql('.foo()');
+        expect(root.first.important).to.eql(true);
+      });
+
       it('parses nested mixins with the rule set', () => {
         const params = '({background-color: red;})';
         const ruleSet = `.desktop-and-old-ie ${ params }`;