From 9bedd252344becfc83c86b2cdcf2f4b45d8e573c Mon Sep 17 00:00:00 2001
From: David Anson <david@dlaa.me>
Date: Sun, 8 Mar 2015 23:08:43 -0700
Subject: [PATCH] Add MD022 with tests, create shared module.

---
 lib/markdownlint.js                      |  3 +-
 lib/rules.js                             | 40 +++++++++++++++++++++++-
 lib/shared.js                            |  3 ++
 test/headers_good.md                     |  5 +++
 test/headers_surrounding_space_atx.md    |  9 ++++++
 test/headers_surrounding_space_setext.md | 15 +++++++++
 test/markdownlint-test.js                |  3 +-
 7 files changed, 75 insertions(+), 3 deletions(-)
 create mode 100644 lib/shared.js
 create mode 100644 test/headers_good.md
 create mode 100644 test/headers_surrounding_space_atx.md
 create mode 100644 test/headers_surrounding_space_setext.md

diff --git a/lib/markdownlint.js b/lib/markdownlint.js
index 03568418..9c643c7c 100644
--- a/lib/markdownlint.js
+++ b/lib/markdownlint.js
@@ -3,6 +3,7 @@
 var fs = require("fs");
 var md = require("markdown-it")();
 var rules = require("./rules");
+var shared = require("./shared");
 
 function numberComparison(a, b) {
   return a - b;
@@ -18,7 +19,7 @@ function lintFile(file, config, callback) {
       callback(err);
     } else {
       var tokens = md.parse(contents, {});
-      var lines = contents.split(/\r\n|\r|\n/);
+      var lines = contents.split(shared.newLineRe);
       tokens.forEach(function forToken(token) {
         if (token.lines) {
           token.line = lines[token.lines[0]];
diff --git a/lib/rules.js b/lib/rules.js
index 2495df83..3928e86e 100644
--- a/lib/rules.js
+++ b/lib/rules.js
@@ -1,5 +1,7 @@
 "use strict";
 
+var shared = require("./shared");
+
 function indentFor(token) {
   return token.line.length - token.line.trimLeft().length;
 }
@@ -253,7 +255,7 @@ module.exports = [
       filterTokens(params.tokens, "code_block", "fence")
         .forEach(function forToken(token) {
           if (token.content && token.content
-            .split(/\r\n|\r|\n/)
+            .split(shared.newLineRe)
             .filter(function filterLine(line) {
               return line;
             }).every(function forLine(line) {
@@ -318,6 +320,42 @@ module.exports = [
     }
   },
 
+  {
+    "name": "MD022",
+    "desc": "Headers should be surrounded by blank lines",
+    "func": function MD022(params, errors) {
+      var prevHeadingLineNumber = 0;
+      var prevMaxLineIndex = -1;
+      var needBlankLine = false;
+      params.tokens.forEach(function forToken(token) {
+        if (token.type === "heading_open") {
+          if ((token.lines[0] - prevMaxLineIndex) === 0) {
+            errors.push(token.lineNumber);
+          }
+          prevHeadingLineNumber = token.lineNumber;
+        } else if (token.type === "heading_close") {
+          needBlankLine = true;
+        } else if (token.type === "inline") {
+          token.content.split(shared.newLineRe)
+            .forEach(function forLine(line, offset) {
+              if (/^(-+|=+)\s*$/.test(line)) {
+                errors.push(token.lines[0] + offset);
+              }
+            });
+        }
+        if (token.lines) {
+          if (needBlankLine) {
+            if ((token.lines[0] - prevMaxLineIndex) === 0) {
+              errors.push(prevHeadingLineNumber);
+            }
+            needBlankLine = false;
+          }
+          prevMaxLineIndex = Math.max(prevMaxLineIndex, token.lines[1]);
+        }
+      });
+    }
+  },
+
   {
     "name": "MD028",
     "desc": "Blank line inside blockquote",
diff --git a/lib/shared.js b/lib/shared.js
new file mode 100644
index 00000000..28d00977
--- /dev/null
+++ b/lib/shared.js
@@ -0,0 +1,3 @@
+"use strict";
+
+module.exports.newLineRe = /\r\n|\r|\n/;
diff --git a/test/headers_good.md b/test/headers_good.md
new file mode 100644
index 00000000..f2576043
--- /dev/null
+++ b/test/headers_good.md
@@ -0,0 +1,5 @@
+# Heading 1
+
+## Heading 2
+
+## Heading 3
\ No newline at end of file
diff --git a/test/headers_surrounding_space_atx.md b/test/headers_surrounding_space_atx.md
new file mode 100644
index 00000000..c811b190
--- /dev/null
+++ b/test/headers_surrounding_space_atx.md
@@ -0,0 +1,9 @@
+# Header 1
+
+## Header 2 {MD022}
+Some text
+## Header 3 {MD022}
+Some text
+## Header 4 {MD022}
+
+## Header 5
\ No newline at end of file
diff --git a/test/headers_surrounding_space_setext.md b/test/headers_surrounding_space_setext.md
new file mode 100644
index 00000000..1a741c40
--- /dev/null
+++ b/test/headers_surrounding_space_setext.md
@@ -0,0 +1,15 @@
+Header 1
+========
+
+Header 2 {MD022}
+----------------
+Some text
+Header 3 {MD022}
+================
+Some text
+Header 4 {MD022}
+================
+Some text
+
+Header 5
+--------
\ No newline at end of file
diff --git a/test/markdownlint-test.js b/test/markdownlint-test.js
index 9bf2ed55..47c27302 100644
--- a/test/markdownlint-test.js
+++ b/test/markdownlint-test.js
@@ -3,6 +3,7 @@
 var fs = require("fs");
 var path = require("path");
 var markdownlint = require("../lib/markdownlint");
+var shared = require("../lib/shared");
 var Q = require("q");
 
 function createTestForFile(file) {
@@ -31,7 +32,7 @@ function createTestForFile(file) {
     var expectedPromise = Q.nfcall(fs.readFile, file, { "encoding": "utf8" })
       .then(
         function fileContents(contents) {
-          var lines = contents.split(/\r\n|\r|\n/);
+          var lines = contents.split(shared.newLineRe);
           var results = {};
           lines.forEach(function forLine(line, lineNum) {
             var regex = /\{(MD\d+)(?::(\d+))?\}/g;