Add false value for atrules option to disable at-rule validation

README.md

@@ -37,12 +37,15 @@ Setup plugin in [stylelint config](http://stylelint.io/user-guide/configuration/
 - [ignore](#ignore)
 - [ignoreProperties](#ignoreproperties)
 - [ignoreValue](#ignorevalue)
+
 #### atrules
 
-Type: `Object` or `null`  
+Type: `Object`, `false` or `null`  
 Default: `null`
 
-An option for extending or altering types syntax dictionary. An atrule definition consists of `prelude` and `descriptors`, both are optional. A `prelude` is a single expression that comes after at-rule name. A `descriptors` is a dictionary like [`properties`](#properties) option but for a specific at-rule. [CSS Value Definition Syntax](https://github.com/csstree/csstree/blob/master/docs/definition-syntax.md) is used to define value's syntax. If a definition starts with `|` it is adding to existing definition value if any. See [CSS syntax reference](https://csstree.github.io/docs/syntax/) for default definitions.
+Using `false` value for the option disables at-rule validation.
+
+Otherwise the option is using for extending or altering at-rules syntax dictionary. An atrule definition consists of `prelude` and `descriptors`, both are optional. A `prelude` is a single expression that comes after at-rule name. A `descriptors` is a dictionary like [`properties`](#properties) option but for a specific at-rule. [CSS Value Definition Syntax](https://github.com/csstree/csstree/blob/master/docs/definition-syntax.md) is used to define value's syntax. If a definition starts with `|` it is adding to existing definition value if any. See [CSS syntax reference](https://csstree.github.io/docs/syntax/) for default definitions.
 
 The following example defines new atrule `@example` with a prelude and two descriptors (a descriptor is the same as a declaration but with no `!important` allowed):
 

lib/index.js

@@ -41,7 +41,8 @@ const plugin = createPlugin(ruleName, function(options) {
     const ignoreProperties = Array.isArray(optionIgnoreProperties)
         ? new Set(optionIgnoreProperties.map(name => String(name).toLowerCase()))
         : false;
-    const syntax = !options.properties && !options.types
+    const atrulesValidationDisabled = options.atrules === false;
+    const syntax = !options.properties && !options.types && !options.atrules
         ? csstree.lexer // default syntax
         : csstree.fork({
             properties: options.properties,
@@ -60,6 +61,12 @@ const plugin = createPlugin(ruleName, function(options) {
                 return;
             }
 
+            // at-rule validation is disabled
+            if (atrulesValidationDisabled) {
+                ignoreAtrules.add(atrule);
+                return;
+            }
+
             if (error = syntax.checkAtruleName(atrule.name)) {
                 ignoreAtrules.add(atrule);
                 utils.report({

test/index.js

@@ -45,6 +45,16 @@ css(null, function(tr) {
     tr.notOk('.foo {\n  width: 10px;\n  color: red green;\n}', invalidValue('color', 3, 14));
 });
 
+// atrules
+css(null, function(tr) {
+    tr.notOk('  @unknown {}', invalid('Unknown at-rule `@unknown`', 1, 3));
+    tr.notOk('  @media ??? {}', invalidPrelude('media', 1, 10));
+});
+css({ atrules: false }, function(tr) {
+    tr.ok('@unknown;');
+    tr.ok('@media ??? {}');
+});
+
 // ignore values with less extenstions
 less(null, function(tr) {
     // variables