fix: mixin !important (#126)

* fix: proposed token important fix

* chore: use join instead of reduce

* chore: update signature to prevent conflict

Author: shellscape

lib/LessParser.js

@@ -98,6 +98,29 @@ module.exports = class LessParser extends Parser {
       tokens = tokens.concat(tokensAfter);
     }
 
+    const importantTokens = [];
+
+    for (const token of tokens) {
+      if (token[1] === '!' || importantTokens.length) {
+        importantTokens.push(token);
+      }
+
+      if (token[1] === 'important') {
+        break;
+      }
+    }
+
+    if (importantTokens.length) {
+      const [bangToken] = importantTokens;
+      const bangIndex = tokens.indexOf(bangToken);
+      const last = importantTokens[importantTokens.length - 1];
+      const start = [bangToken[2], bangToken[3]];
+      const end = [last[4], last[5]];
+      const combined = importantTokens.map((t) => t[1]).join('');
+      const newToken = ['word', combined].concat(start, end);
+      tokens.splice(bangIndex, importantTokens.length, newToken);
+    }
+
     const importantIndex = tokens.findIndex((t) => importantPattern.test(t[1]));
 
     if (importantIndex > 0) {

test/parser/mixins.test.js

@@ -175,6 +175,30 @@ test('!important, no whitespace', (t) => {
   t.is(nodeToString(root), less);
 });
 
+test('!important, whitespace between', (t) => {
+  const less = `
+                    .foo()! important;
+                `;
+  const root = parse(less);
+  const { first } = root;
+  t.is(first.name, 'foo');
+  t.is(first.params, '()');
+  t.is(first.important, true);
+  t.is(nodeToString(root), less);
+});
+
+test('!important, whitespace before and between', (t) => {
+  const less = `
+                    .foo() ! important;
+                `;
+  const root = parse(less);
+  const { first } = root;
+  t.is(first.name, 'foo');
+  t.is(first.params, '()');
+  t.is(first.important, true);
+  t.is(nodeToString(root), less);
+});
+
 test('parses nested mixins with the rule set', (t) => {
   const params = '({background-color: red;})';
   const ruleSet = `.desktop-and-old-ie ${params}`;