Add comma spacing rule

lib/stylec/rule/comma-spacing.js

@@ -0,0 +1,60 @@
+/**
+ * Internal dependencies.
+ */
+
+var Rule = require('../rule');
+
+var Comma = Rule.create({
+  error: 'Bad comma spacing',
+
+  option: {
+    key: 'commaspace',
+    type: 'enum',
+    values: ['after', 'before', 'surround'],
+    defaults: 'off'
+  },
+
+  on: {
+    Punctuator: 'check',
+  },
+});
+
+/**
+ * Perform the check.
+ *
+ * @param {Object} token
+ * @api public
+ */
+
+Comma.prototype.check = function(token) {
+  if (token.value !== ',') return;
+
+  var range = [token.range[0] - 1, token.range[1] + 1];
+  var str = this.source.range(range);
+  var error = false;
+  var test = function(char) {
+    return /\s/.test(char);
+  };
+
+  switch (this.option()) {
+    case 'after':
+      if (!test(str[2]) || test(str[0])) error = true;
+      break;
+    case 'before':
+      if (!test(str[0]) || test(str[2])) error = true;
+      break;
+    case 'surround':
+      if (!test(str[0]) || !test(str[2])) error = true;
+      break;
+  }
+
+  if (error) {
+    this.badToken(token);
+  }
+};
+
+/**
+ * Primary export.
+ */
+
+module.exports = Comma;

test/cases/array-trailing-comma/prohibited.js

@@ -1,4 +1,4 @@
-/* stylec arrcomma: prohibited */
+/* stylec arrcomma: prohibited, commaspace: off */
 
 var good = [
   1,

test/cases/comma-spacing/after.js

@@ -0,0 +1,8 @@
+/* stylec commaspace: after */
+
+var good = (1, 2, 3);
+var good = [1, 2, 3];
+var good, verygood, awesome;
+
+var bad = [1 ,2 ,3];
+var bad ,boo ,bar = null;

test/cases/comma-spacing/after.result.js

@@ -0,0 +1,6 @@
+module.exports = [
+  { line: 7, column: 13 },
+  { line: 7, column: 16 },
+  { line: 8, column: 8 },
+  { line: 8, column: 13 },
+];

test/cases/comma-spacing/before.js

@@ -0,0 +1,8 @@
+/* stylec commaspace: before */
+
+var good = (1 ,2 ,3);
+var good = [1 ,2 ,3];
+var good ,verygood ,awesome;
+
+var bad = [1, 2, 3];
+var bad, boo, bar = null;

test/cases/comma-spacing/before.result.js

@@ -0,0 +1,6 @@
+module.exports = [
+  { line: 7, column: 12 },
+  { line: 7, column: 15 },
+  { line: 8, column: 7 },
+  { line: 8, column: 12 },
+];

test/cases/comma-spacing/surround.js

@@ -0,0 +1,8 @@
+/* stylec commaspace: surround */
+
+var good = (1 , 2 , 3);
+var good = [1 , 2 , 3];
+var good , verygood , awesome;
+
+var bad = [1, 2, 3];
+var bad, boo, bar = null;

test/cases/comma-spacing/surround.result.js

@@ -0,0 +1,6 @@
+module.exports = [
+  { line: 7, column: 12 },
+  { line: 7, column: 15 },
+  { line: 8, column: 7 },
+  { line: 8, column: 12 },
+];