From debc08bca178434f9b1e26cf3f63949a5f2747ce Mon Sep 17 00:00:00 2001
From: David Anson <david@dlaa.me>
Date: Thu, 21 Mar 2019 21:42:24 -0700
Subject: [PATCH] Re-implement MD022/blanks-around-headings to ignore comments
 and blockquotes.

---
 lib/md022.js                                  | 30 ++++---------------
 lib/md031.js                                  |  5 ++--
 test/blanks-around.md                         |  4 +--
 test/blockquote-headings.md                   |  8 ++---
 test/headings_with_spaces_at_the_beginning.md |  4 +--
 5 files changed, 16 insertions(+), 35 deletions(-)

diff --git a/lib/md022.js b/lib/md022.js
index 53abd9f4..c341281f 100644
--- a/lib/md022.js
+++ b/lib/md022.js
@@ -3,36 +3,18 @@
 "use strict";
 
 const shared = require("./shared");
+const { addErrorContext, filterTokens, isBlankLine } = shared;
 
 module.exports = {
   "names": [ "MD022", "blanks-around-headings", "blanks-around-headers" ],
   "description": "Headings should be surrounded by blank lines",
   "tags": [ "headings", "headers", "blank_lines" ],
   "function": function MD022(params, onError) {
-    let prevHeadingLineNumber = 0;
-    let prevMaxLineIndex = -1;
-    let needBlankLine = false;
-    params.tokens.forEach(function forToken(token) {
-      if (token.type === "heading_open") {
-        if ((token.map[0] - prevMaxLineIndex) === 0) {
-          shared.addErrorContext(onError, token.lineNumber,
-            token.line.trim());
-        }
-      } else if (token.type === "heading_close") {
-        needBlankLine = true;
-      }
-      if (token.map) {
-        if (needBlankLine) {
-          if ((token.map[0] - prevMaxLineIndex) === 0) {
-            shared.addErrorContext(onError, prevHeadingLineNumber,
-              params.lines[prevHeadingLineNumber - 1].trim());
-          }
-          needBlankLine = false;
-        }
-        prevMaxLineIndex = Math.max(prevMaxLineIndex, token.map[1]);
-      }
-      if (token.type === "heading_open") {
-        prevHeadingLineNumber = token.lineNumber;
+    const { lines } = params;
+    filterTokens(params, "heading_open", (token) => {
+      const [ topIndex, nextIndex ] = token.map;
+      if (!isBlankLine(lines[topIndex - 1]) || !isBlankLine(lines[nextIndex])) {
+        addErrorContext(onError, topIndex + 1, lines[topIndex].trim());
       }
     });
   }
diff --git a/lib/md031.js b/lib/md031.js
index eab64c6c..073a4d80 100644
--- a/lib/md031.js
+++ b/lib/md031.js
@@ -11,10 +11,9 @@ module.exports = {
   "tags": [ "code", "blank_lines" ],
   "function": function MD031(params, onError) {
     const { lines } = params;
-    const { length } = lines;
     forEachLine(function forLine(line, i, inCode, onFence) {
-      if (((onFence > 0) && (i - 1 >= 0) && !isBlankLine(lines[i - 1])) ||
-          ((onFence < 0) && (i + 1 < length) && !isBlankLine(lines[i + 1]))) {
+      if (((onFence > 0) && !isBlankLine(lines[i - 1])) ||
+          ((onFence < 0) && !isBlankLine(lines[i + 1]))) {
         addErrorContext(onError, i + 1, lines[i].trim());
       }
     });
diff --git a/test/blanks-around.md b/test/blanks-around.md
index 33570102..88dc8b30 100644
--- a/test/blanks-around.md
+++ b/test/blanks-around.md
@@ -5,11 +5,11 @@
 ## MD022/blanks-around-headings
 
 >
-### Alpha {MD022}
+### Alpha
 > >
 
 <!-- comment -->
-### Beta {MD022}
+### Beta
 <!-- comments --><!-- comments -->
 
 > Text
diff --git a/test/blockquote-headings.md b/test/blockquote-headings.md
index b1fc9e29..211f5aaf 100644
--- a/test/blockquote-headings.md
+++ b/test/blockquote-headings.md
@@ -20,17 +20,17 @@ Text
 
 - Item
   item
-  > # Quoted heading in list {MD025}
+  > # Quoted heading in list {MD022} {MD025}
 - Item
   item
-  > > # Double-quoted heading in list {MD025}
+  > > # Double-quoted heading in list {MD022} {MD025}
 - Item
   item
-  > ## Quoted sub-heading in list
+  > ## Quoted sub-heading in list {MD022}
 - Item
 - Item
   item
-  >  ## Quoted indented sub-heading in list {MD023}
+  >  ## Quoted indented sub-heading in list {MD022} {MD023}
 - Item
 
 Text
diff --git a/test/headings_with_spaces_at_the_beginning.md b/test/headings_with_spaces_at_the_beginning.md
index 4ab2808b..ac434375 100644
--- a/test/headings_with_spaces_at_the_beginning.md
+++ b/test/headings_with_spaces_at_the_beginning.md
@@ -16,5 +16,5 @@ Some text
   ```
 
 * This is another case where MD023 shouldn't be triggered
-  # Test {MD023} Valid heading for CommonMark (see section 5.2)
-    # Test {MD023} Also valid heading for CommonMark
+  # Test {MD022} {MD023} Valid heading for CommonMark (see section 5.2)
+    # Test {MD022} {MD023} Also valid heading for CommonMark