Add MD032 with tests, improve infrastructure.

lib/markdownlint.js

@@ -3,6 +3,14 @@
 var fs = require("fs");
 var rules = require("./rules");
 
+function numberComparison(a, b) {
+  return a - b;
+}
+
+function uniqueFilterForSorted(value, index, array) {
+  return (index === 0) || (value > array[index - 1]);
+}
+
 function lintFile(file, options, callback) {
   fs.readFile(file, { "encoding": "utf8" }, function readFile(err, contents) {
     if (err) {
@@ -14,7 +22,8 @@ function lintFile(file, options, callback) {
         var rule = rules[name];
         var errors = rule(lines);
         if (errors.length) {
-          result[name] = errors;
+          errors.sort(numberComparison);
+          result[name] = errors.filter(uniqueFilterForSorted);
         }
       });
       callback(null, result);

lib/rules.js

@@ -26,5 +26,31 @@ module.exports = {
       }
     });
     return errors;
+  },
+
+  "MD032": function MD032(lines) {
+    // Some parsers have trouble detecting lists without surrounding
+    // whitespace, so examine the lines directly.
+    var errors = [];
+    var inList = false;
+    var inCode = false;
+    var prevLine = "";
+    lines.forEach(function forLine(line, lineNum) {
+      if (!inCode) {
+        var listMarker = line.trim().match(/^([\*\+\-]|(\d+\.))\s/);
+        if (listMarker && !inList && !prevLine.match(/^($|\s)/)) {
+          errors.push(lineNum + 1);
+        } else if (!listMarker && inList && !line.match(/^($|\s)/)) {
+          errors.push(lineNum);
+        }
+        inList = listMarker;
+      }
+      if (line.trim().match(/^(```|~~~)/)) {
+        inCode = !inCode;
+        inList = false;
+      }
+      prevLine = line;
+    });
+    return errors;
   }
 };

test/lists_without_blank_lines.md

@@ -0,0 +1,75 @@
+* list (on first line)
+
+text
+
+* list
+
+text
+* list {MD032}
+text
++ list {MD032}
+text
+- list {MD032}
+text
+1. list {MD032}
+text
+
+* list
+* list {MD032}
+text
+
+text
+10. list {MD032}
+20. list
+
+text
+
+* list
+  * list
+    * list
+
+text
+
+* list
+  with hanging indent
+  * list
+    with hanging indent
+* list
+  with hanging indent
+
+Note: list without hanging indent violates MD032
+
+* list
+
+  item with blank lines
+
+* list
+
+  item with blank lines
+
+text
+
+```js
+/*
+ * code block
+ * not a list
+ */
+```
+
+text
+
+* list {MD032}
+``` {MD031}
+code
+```
+
+text
+
+```
+code
+``` {MD031}
+* list {MD032}
+
+text
+
+* list (on last line without newline)