Update MD041/first-line-h1 to allow secondary headings if a YAML title is present (refs #116).

doc/Rules.md

@@ -51,25 +51,28 @@ Aliases: first-heading-h1, first-header-h1
 
 Parameters: level (number; default 1)
 
-This rule is triggered when the first heading in the document isn't a h1 heading:
+This rule is intended to ensure document headings start at the top level and
+is triggered when the first heading in the document isn't an h1 heading:
 
 ```markdown
-## This isn't a H1 heading
+## This isn't an H1 heading
 
 ### Another heading
 ```
 
-The first heading in the document should be a h1 heading:
+The first heading in the document should be an h1 heading:
 
 ```markdown
-# Start with a H1 heading
+# Start with an H1 heading
 
-## Then use a H2 for subsections
+## Then use an H2 for subsections
 ```
 
 Note: The `level` parameter can be used to change the top level (ex: to h2) in
 cases where an h1 is added externally.
 
+See also: [MD041](#md041) for an improved version of this rule.
+
 <a name="md003"></a>
 
 ## MD003 - Heading style
@@ -215,7 +218,6 @@ the same ending column:
 ...
 ```
 
-
 <a name="md006"></a>
 
 ## MD006 - Consider starting bulleted lists at the beginning of the line
@@ -732,7 +734,7 @@ Aliases: single-h1
 Parameters: level (number; default 1)
 
 This rule is triggered when a top level heading is in use (the first line of
-the file is a h1 heading), and more than one h1 heading is in use in the
+the file is an h1 heading), and more than one h1 heading is in use in the
 document:
 
 ```markdown
@@ -753,7 +755,7 @@ headings:
 ## Another heading
 ```
 
-Rationale: A top level heading is a h1 on the first line of the file, and
+Rationale: A top level heading is an h1 on the first line of the file, and
 serves as the title for the document. If this convention is in use, then there
 can not be more than one title for the document, and the entire document
 should be contained within this heading.
@@ -1349,14 +1351,14 @@ Aliases: first-line-h1
 
 Parameters: level, front_matter_title (number; default 1, string; default "^\s*title:")
 
-This rule is triggered when the first line in the file isn't a top level (h1)
-heading:
+This rule is intended to ensure documents have a title and is triggered when
+the first line in the file isn't a top level (h1) heading:
 
 ```markdown
 This is a file without a heading
 ```
 
-To fix this, add a heading to the top of your file:
+To fix this, add a top level heading to the beginning of the file:
 
 ```markdown
 # File with heading
@@ -1364,10 +1366,10 @@ To fix this, add a heading to the top of your file:
 This is a file with a top level heading
 ```
 
-The `level` parameter can be used to change the top level (ex: to h2) in cases
+Note: The `level` parameter can be used to change the top level (ex: to h2) in cases
 where an h1 is added externally.
 
-If front matter is present and contains a [YAML](https://en.wikipedia.org/wiki/YAML)
+If [YAML](https://en.wikipedia.org/wiki/YAML) front matter is present and contains a
 `title` property (commonly used with blog posts), this rule will not report a
 violation. To use a different property name in front matter, specify the text
 of a regular expression via the `front_matter_title` parameter. To disable the

lib/md041.js

@@ -10,24 +10,24 @@ module.exports = {
   "tags": [ "headings", "headers" ],
   "function": function MD041(params, onError) {
     const level = params.config.level || 1;
-    const frontMatterTitle = params.config.front_matter_title;
     const tag = "h" + level;
+    const frontMatterTitle = params.config.front_matter_title;
+    const ignoreFrontMatter =
+      (frontMatterTitle !== undefined) && !frontMatterTitle;
     const frontMatterTitleRe =
       new RegExp(frontMatterTitle || "^\\s*title\\s*[:=]", "i");
-    params.tokens.every(function forToken(token) {
+    const foundFrontMatterTitle = !ignoreFrontMatter &&
+      params.frontMatterLines.some((line) => frontMatterTitleRe.test(line));
+    if (!foundFrontMatterTitle) {
+      params.tokens.every((token) => {
         if (token.type === "html_block") {
           return true;
-      } else if (token.type === "heading_open") {
-        if (token.tag !== tag) {
-          shared.addErrorContext(onError, token.lineNumber, token.line);
         }
-      } else if (((frontMatterTitle !== undefined) && !frontMatterTitle) ||
-        !params.frontMatterLines.some(function forLine(line) {
-          return frontMatterTitleRe.test(line);
-        })) {
+        if ((token.type !== "heading_open") || (token.tag !== tag)) {
           shared.addErrorContext(onError, token.lineNumber, token.line);
         }
         return false;
       });
     }
+  }
 };

test/front-matter-title-h2.json

@@ -0,0 +1,8 @@
+{
+  "default": true,
+  "MD002": {
+    "level": 2
+  },
+  "MD013": false,
+  "MD041": true
+}

test/front-matter-title-h2.md

@@ -0,0 +1,9 @@
+---
+layout: post
+title:  "Welcome to Jekyll!"
+date:   2015-11-17 16:16:01 -0600
+categories: jekyll update
+---
+## Secondary heading
+
+Front matter from [Jekyll documentation](https://jekyllrb.com/docs/posts/#a-typical-post).