Add MD003 with tests, add JSON config for rules.

lib/markdownlint.js

@@ -12,17 +12,21 @@ function uniqueFilterForSorted(value, index, array) {
   return (index === 0) || (value > array[index - 1]);
 }
 
-function lintFile(file, options, callback) {
+function lintFile(file, config, callback) {
   fs.readFile(file, { "encoding": "utf8" }, function readFile(err, contents) {
     if (err) {
       callback(err);
     } else {
-      var tokens = md.parse(contents);
-      var lines = contents.split(/\r\n|\r|\n/g);
+      var params = {
+        "tokens": md.parse(contents),
+        "lines": contents.split(/\r\n|\r|\n/g)
+      };
       var result = {};
       rules.forEach(function forRule(rule) {
+        var ruleConfig = config[rule.name];
+        params.options = (ruleConfig instanceof Object) ? ruleConfig : {};
         var errors = [];
-        rule.func(errors, tokens, lines);
+        rule.func(params, errors);
         if (errors.length) {
           errors.sort(numberComparison);
           result[rule.name] = errors.filter(uniqueFilterForSorted);
@@ -34,12 +38,14 @@ function lintFile(file, options, callback) {
 }
 
 module.exports = function markdownlint(options, callback) {
-  var results = {};
+  options = options || {};
   var files = options.files || [];
+  var config = options.config || {};
+  var results = {};
   function lintFiles() {
     var file = files.shift();
     if (file) {
-      lintFile(file, options, function lintFileCallback(err, result) {
+      lintFile(file, config, function lintFileCallback(err, result) {
         if (err) {
           callback(err);
         } else {

lib/rules.js

@@ -4,6 +4,16 @@ function lineNumberFrom(token) {
   return token.lines[0] + 1;
 }
 
+function headingStyleFrom(token, lines) {
+  if ((token.lines[1] - token.lines[0]) === 1) {
+    if (lines[token.lines[0]].match(/#\s*$/)) {
+      return "atx_closed";
+    }
+    return "atx";
+  }
+  return "setext";
+}
+
 function padAndTrim(lines) {
   return [].concat(
     "",
@@ -17,9 +27,9 @@ module.exports = [
   {
     "name": "MD001",
     "desc": "Header levels should only increment by one level at a time",
-    "func": function MD001(errors, tokens) {
+    "func": function MD001(params, errors) {
       var prevLevel = 0;
-      tokens.filter(function filterToken(token) {
+      params.tokens.filter(function filterToken(token) {
         return (token.type === "heading_open");
       }).forEach(function forToken(token) {
         if (prevLevel && (token.hLevel > prevLevel + 1)) {
@@ -33,8 +43,8 @@ module.exports = [
   {
     "name": "MD002",
     "desc": "First header should be a h1 header",
-    "func": function MD002(errors, tokens) {
-      tokens.every(function forToken(token) {
+    "func": function MD002(params, errors) {
+      params.tokens.every(function forToken(token) {
         if (token.type === "heading_open") {
           if (token.hLevel !== 1) {
             errors.push(lineNumberFrom(token));
@@ -46,13 +56,32 @@ module.exports = [
     }
   },
 
+  {
+    "name": "MD003",
+    "desc": "Header style",
+    "func": function MD003(params, errors) {
+      var style = params.options.style || "consistent";
+      var headings = params.tokens.filter(function filterToken(token) {
+        return (token.type === "heading_open");
+      });
+      if ((style === "consistent") && headings.length) {
+        style = headingStyleFrom(headings[0], params.lines);
+      }
+      headings.forEach(function forToken(token) {
+        if (headingStyleFrom(token, params.lines) !== style) {
+          errors.push(lineNumberFrom(token));
+        }
+      });
+    }
+  },
+
   {
     "name": "MD031",
     "desc": "Fenced code blocks should be surrounded by blank lines",
-    "func": function MD031(errors, tokens, lines) {
+    "func": function MD031(params, errors) {
       // Some parsers have trouble detecting fenced code blocks without
       // surrounding whitespace, so examine the lines directly.
-      lines = padAndTrim(lines);
+      var lines = padAndTrim(params.lines);
       var inCode = false;
       lines.forEach(function forLine(line, lineNumber) {
         if (line.match(/^(```|~~~)/)) {
@@ -69,13 +98,13 @@ module.exports = [
   {
     "name": "MD032",
     "desc": "Lists should be surrounded by blank lines",
-    "func": function MD032(errors, tokens, lines) {
+    "func": function MD032(params, errors) {
       // Some parsers have trouble detecting lists without surrounding
       // whitespace, so examine the lines directly.
       var inList = false;
       var inCode = false;
       var prevLine = "";
-      lines.forEach(function forLine(line, lineNumber) {
+      params.lines.forEach(function forLine(line, lineNumber) {
         if (!inCode) {
           var listMarker = line.trim().match(/^([\*\+\-]|(\d+\.))\s/);
           if (listMarker && !inList && !prevLine.match(/^($|\s)/)) {