From 1db87ef0c6b9eee11c8358ea8bfd0d0d6e729b98 Mon Sep 17 00:00:00 2001
From: David Anson <david@dlaa.me>
Date: Wed, 20 Mar 2019 21:48:18 -0700
Subject: [PATCH] Update MD031/blanks-around-fences and
 MD032/blanks-around-lists to ignore comments and blockquotes (fixes #171,
 fixes #172).

---
 lib/md031.js              | 12 ++++----
 lib/md032.js              | 20 ++++++-------
 lib/shared.js             |  7 +++++
 test/blanks-around.md     | 61 +++++++++++++++++++++++++++++++++++++++
 test/markdownlint-test.js | 36 +++++++++++++++++++++++
 5 files changed, 120 insertions(+), 16 deletions(-)
 create mode 100644 test/blanks-around.md

diff --git a/lib/md031.js b/lib/md031.js
index 562ca601..eab64c6c 100644
--- a/lib/md031.js
+++ b/lib/md031.js
@@ -3,17 +3,19 @@
 "use strict";
 
 const shared = require("./shared");
+const { addErrorContext, forEachLine, isBlankLine } = shared;
 
 module.exports = {
   "names": [ "MD031", "blanks-around-fences" ],
   "description": "Fenced code blocks should be surrounded by blank lines",
   "tags": [ "code", "blank_lines" ],
   "function": function MD031(params, onError) {
-    const lines = params.lines;
-    shared.forEachLine(function forLine(line, i, inCode, onFence) {
-      if (((onFence > 0) && (i - 1 >= 0) && lines[i - 1].length) ||
-          ((onFence < 0) && (i + 1 < lines.length) && lines[i + 1].length)) {
-        shared.addErrorContext(onError, i + 1, lines[i].trim());
+    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]))) {
+        addErrorContext(onError, i + 1, lines[i].trim());
       }
     });
   }
diff --git a/lib/md032.js b/lib/md032.js
index 30140573..cb84f01a 100644
--- a/lib/md032.js
+++ b/lib/md032.js
@@ -3,24 +3,22 @@
 "use strict";
 
 const shared = require("./shared");
-
-const blankLineRe = /^[\s>]*$/;
+const { addErrorContext, flattenLists, isBlankLine } = shared;
 
 module.exports = {
   "names": [ "MD032", "blanks-around-lists" ],
   "description": "Lists should be surrounded by blank lines",
   "tags": [ "bullet", "ul", "ol", "blank_lines" ],
   "function": function MD032(params, onError) {
-    shared.flattenLists().filter((list) => !list.nesting).forEach((list) => {
-      const firstLineIndex = list.open.map[0];
-      if (!blankLineRe.test(params.lines[firstLineIndex - 1] || "")) {
-        shared.addErrorContext(
-          onError, firstLineIndex + 1, params.lines[firstLineIndex].trim());
+    const { lines } = params;
+    flattenLists().filter((list) => !list.nesting).forEach((list) => {
+      const firstIndex = list.open.map[0];
+      if (!isBlankLine(lines[firstIndex - 1])) {
+        addErrorContext(onError, firstIndex + 1, lines[firstIndex].trim());
       }
-      const bottomLineIndex = list.lastLineIndex - 1;
-      if (!blankLineRe.test(params.lines[bottomLineIndex + 1] || "")) {
-        shared.addErrorContext(
-          onError, bottomLineIndex + 1, params.lines[bottomLineIndex].trim());
+      const lastIndex = list.lastLineIndex - 1;
+      if (!isBlankLine(lines[lastIndex + 1])) {
+        addErrorContext(onError, lastIndex + 1, lines[lastIndex].trim());
       }
     });
   }
diff --git a/lib/shared.js b/lib/shared.js
index e6f516cb..82a96d3d 100644
--- a/lib/shared.js
+++ b/lib/shared.js
@@ -64,6 +64,13 @@ module.exports.isEmptyString = function isEmptyString(str) {
   return str.length === 0;
 };
 
+// Returns true iff the input line is blank (no content)
+// Example: Contains nothing, whitespace, or comments
+const blankLineRe = />|(?:<!--.*?-->)/g;
+module.exports.isBlankLine = function isBlankLine(line) {
+  return !line || !line.trim() || !line.replace(blankLineRe, "").trim();
+};
+
 // Replaces the text of all properly-formatted HTML comments with whitespace
 // This preserves the line/column information for the rest of the document
 // Trailing whitespace is avoided with a '\' character in the last column
diff --git a/test/blanks-around.md b/test/blanks-around.md
new file mode 100644
index 00000000..33570102
--- /dev/null
+++ b/test/blanks-around.md
@@ -0,0 +1,61 @@
+# Blanks Around
+
+---
+
+## MD022/blanks-around-headings
+
+>
+### Alpha {MD022}
+> >
+
+<!-- comment -->
+### Beta {MD022}
+<!-- comments --><!-- comments -->
+
+> Text
+>
+> ### Gamma
+> >
+> > Text
+
+---
+
+## MD031/blanks-around-fences
+
+> >
+```js
+console.log();
+```
+>
+
+<!-- prettier-ignore -->
+```js
+console.log();
+```
+<!-- prettier-ignore -->
+
+> Text
+>
+> ```js
+> console.log();
+> ```
+> >
+> >Text
+
+---
+
+## MD032/blanks-around-lists
+
+>
+- List item
+>>
+
+  <!--comments--><!--  comments  -->
+- List item
+<!--comment-->
+
+> Text
+>
+> - List item
+>>
+>> Text
diff --git a/test/markdownlint-test.js b/test/markdownlint-test.js
index 6f8d57b2..da0b2788 100644
--- a/test/markdownlint-test.js
+++ b/test/markdownlint-test.js
@@ -1396,6 +1396,42 @@ function clearHtmlCommentTextEmbedded(test) {
   test.done();
 };
 
+module.exports.isBlankLine = function isBlankLine(test) {
+  test.expect(25);
+  const blankLines = [
+    null,
+    "",
+    " ",
+    "  ",
+    "\t\t\t",
+    "\r",
+    "\n",
+    "\t\r\n",
+    " <!-- text --> ",
+    "<!--text-->",
+    "<!---->",
+    "<!-- text -->\t<!-- text -->",
+    ">",
+    "> ",
+    "> > > \t",
+    "> <!--text-->",
+    ">><!--text-->"
+  ];
+  blankLines.forEach((line) => test.ok(shared.isBlankLine(line), line));
+  const nonBlankLines = [
+    "text",
+    " text ",
+    ".",
+    "> .",
+    "<!--text--> text",
+    "<!--->",
+    "<!--",
+    "-->"
+  ];
+  nonBlankLines.forEach((line) => test.ok(!shared.isBlankLine(line), line));
+  test.done();
+};
+
 module.exports.trimLeftRight = function trimLeftRight(test) {
   const inputs = [
     "text text",