Update definition of helpers.isBlankLine to treat unterminated start/end comments as potentially blank lines (fixes #431).

demo/markdownlint-browser.js

@@ -77,12 +77,18 @@ module.exports.isObject = function isObject(obj) {
     return (obj !== null) && (typeof obj === "object") && !Array.isArray(obj);
 };
 // Returns true iff the input line is blank (no content)
-// Example: Contains nothing, whitespace, or comments
+// Example: Contains nothing, whitespace, or comment (unclosed start/end okay)
-var blankLineRe = />|(?:<!--.*?-->)/g;
 module.exports.isBlankLine = function isBlankLine(line) {
     // Call to String.replace follows best practices and is not a security check
     // False-positive for js/incomplete-multi-character-sanitization
-    return !line || !line.trim() || !line.replace(blankLineRe, "").trim();
+    return (!line ||
+        !line.trim() ||
+        !line
+            .replace(/<!--.*?-->/g, "")
+            .replace(/<!--.*$/g, "")
+            .replace(/^.*-->/g, "")
+            .replace(/>/g, "")
+            .trim());
 };
 /**
  * Compare function for Array.prototype.sort for ascending order of numbers.

helpers/helpers.js

@@ -63,12 +63,20 @@ module.exports.isObject = function isObject(obj) {
 };
 
 // Returns true iff the input line is blank (no content)
-// Example: Contains nothing, whitespace, or comments
+// Example: Contains nothing, whitespace, or comment (unclosed start/end okay)
-const blankLineRe = />|(?:<!--.*?-->)/g;
 module.exports.isBlankLine = function isBlankLine(line) {
   // Call to String.replace follows best practices and is not a security check
   // False-positive for js/incomplete-multi-character-sanitization
-  return !line || !line.trim() || !line.replace(blankLineRe, "").trim();
+  return (
+    !line ||
+    !line.trim() ||
+    !line
+      .replace(/<!--.*?-->/g, "")
+      .replace(/<!--.*$/g, "")
+      .replace(/^.*-->/g, "")
+      .replace(/>/g, "")
+      .trim()
+  );
 };
 
 /**

test/lists-with-commented-items.md

@@ -0,0 +1,38 @@
+# Lists with Commented Items
+
+Text
+
+- item <!-- comment -->
+- item <!-- comment -->
+<!--
+  - commented subitem: description
+  - commented subitem: description
+-->
+- item <!-- comment -->
+- item <!-- comment -->
+
+Text
+
+- item <!-- comment -->
+- item <!-- comment -->
+<!-- - commented subitem: description
+     - commented subitem: description -->
+- item <!-- comment -->
+- item <!-- comment -->
+
+Text
+
+- item <!-- comment -->
+<!-- - commented subitem: description -->
+- item <!-- comment -->
+
+Text
+
+- item <!-- comment -->
+- item <!-- comment -->
+<!-- - commented subitem: description -->
+<!-- - commented subitem: description -->
+- item <!-- comment -->
+- item <!-- comment -->
+
+Text

test/markdownlint-test-helpers.js

@@ -226,7 +226,7 @@ bar`
 });
 
 test("isBlankLine", (t) => {
-  t.plan(25);
+  t.plan(29);
   const blankLines = [
     null,
     "",
@@ -244,7 +244,11 @@ test("isBlankLine", (t) => {
     "> ",
     "> > > \t",
     "> <!--text-->",
-    ">><!--text-->"
+    ">><!--text-->",
+    "<!--",
+    "  <!-- text",
+    "text -->  ",
+    "-->"
   ];
   blankLines.forEach((line) => t.true(helpers.isBlankLine(line), line || ""));
   const nonBlankLines = [
@@ -253,9 +257,9 @@ test("isBlankLine", (t) => {
     ".",
     "> .",
     "<!--text--> text",
-    "<!--->",
+    "text <!--text-->",
-    "<!--",
+    "text <!--",
-    "-->"
+    "--> text"
   ];
   nonBlankLines.forEach((line) => t.true(!helpers.isBlankLine(line), line));
 });