add basic tests

Author: lahmatiy

package.json

@@ -18,11 +18,16 @@
     "validator",
     "syntax"
   ],
+  "scripts": {
+    "test": "tape test"
+  },
   "dependencies": {
     "css-tree": "1.0.0-alpha16",
     "stylelint": "^7.0.0"
   },
   "devDependencies": {
+    "stylelint-rule-tester": "^0.6.2",
+    "tape": "^4.6.3"
   },
   "eslintConfig": {
     "env": {
@@ -32,7 +37,13 @@
     "rules": {
       "no-duplicate-case": 2,
       "no-undef": 2,
-      "no-unused-vars": [2, {"vars": "all", "args": "after-used"}]
+      "no-unused-vars": [
+        2,
+        {
+          "vars": "all",
+          "args": "after-used"
+        }
+      ]
     }
   }
 }

test/index.js

@@ -0,0 +1,12 @@
+var ruleTester = require('stylelint-rule-tester');
+var validator = require('..');
+var messages = validator.messages;
+var testRule = ruleTester(validator.rule, validator.ruleName);
+
+testRule('base test', function(tr) {
+    tr.ok('.foo { color: red }');
+    tr.notOk('.foo { color: red green }', messages.uncomplete('color'));
+    tr.notOk('.foo { color: 1 }', messages.invalid('color'));
+    tr.notOk('.foo { color: #12345 }', messages.invalid('color'));
+    tr.notOk('.foo { color: &a }', messages.parseError('&a'));
+});