Allow question mark by default for MD026/no-trailing-punctuation (fixes #276).

doc/Rules.md

@@ -895,7 +895,7 @@ Tags: headings, headers
 
 Aliases: no-trailing-punctuation
 
-Parameters: punctuation (string; default ".,;:!?。，；：！？")
+Parameters: punctuation (string; default ".,;:!。，；：！")
 
 Fixable: Most violations can be fixed by tooling
 
@@ -914,7 +914,8 @@ To fix this, remove the trailing punctuation:
 
 Note: The `punctuation` parameter can be used to specify what characters count
 as punctuation at the end of a heading. For example, you can change it to
-`".,;:!"` to allow headings that end with a question mark, such as in an FAQ.
+`".,;:"` to allow headings that end with an exclamation point. Question mark is
+allowed by default because of how common it is in headings of FAQ-style documents.
 Setting the `punctuation` parameter to `""` allows all characters - and is
 equivalent to disabling the rule.
 

helpers/helpers.js

@@ -35,7 +35,11 @@ const linkRe = /\[(?:[^[\]]|\[[^\]]*\])*\](?:\(\S*\))?/g;
 module.exports.utf8Encoding = "utf8";
 
 // All punctuation characters (normal and full-width)
-module.exports.allPunctuation = ".,;:!?。，；：！？";
+const allPunctuation = ".,;:!?。，；：！？";
+module.exports.allPunctuation = allPunctuation;
+
+// All punctuation characters without question mark (normal and full-width)
+module.exports.allPunctuationNoQuestion = allPunctuation.replace(/[?？]/gu, "");
 
 // Returns true iff the input is a number
 module.exports.isNumber = function isNumber(obj) {

lib/md026.js

@@ -2,7 +2,7 @@
 
 "use strict";
 
-const { addError, allPunctuation, escapeForRegExp, forEachHeading } =
+const { addError, allPunctuationNoQuestion, escapeForRegExp, forEachHeading } =
   require("../helpers");
 
 module.exports = {
@@ -11,8 +11,9 @@ module.exports = {
   "tags": [ "headings", "headers" ],
   "function": function MD026(params, onError) {
     let punctuation = params.config.punctuation;
-    punctuation =
+    punctuation = String(
-      String((punctuation === undefined) ? allPunctuation : punctuation);
+      (punctuation === undefined) ? allPunctuationNoQuestion : punctuation
+    );
     const trailingPunctuationRe =
       new RegExp("\\s*[" + escapeForRegExp(punctuation) + "]+$");
     forEachHeading(params, (heading) => {

schema/build-config-schema.js

@@ -222,6 +222,14 @@ rules.forEach(function forRule(rule) {
       };
       break;
     case "MD026":
+      scheme.properties = {
+        "punctuation": {
+          "description": "Punctuation characters",
+          "type": "string",
+          "default": ".,;:!。，；：！"
+        }
+      };
+      break;
     case "MD036":
       scheme.properties = {
         "punctuation": {

schema/markdownlint-config-schema.json

@@ -763,7 +763,7 @@
         "punctuation": {
           "description": "Punctuation characters",
           "type": "string",
-          "default": ".,;:!?。，；：！？"
+          "default": ".,;:!。，；：！"
         }
       },
       "additionalProperties": false
@@ -779,7 +779,7 @@
         "punctuation": {
           "description": "Punctuation characters",
           "type": "string",
-          "default": ".,;:!?。，；：！？"
+          "default": ".,;:!。，；：！"
         }
       },
       "additionalProperties": false

test/heading_trailing_punctuation.md

@@ -10,7 +10,7 @@
 
 ## Heading {MD026} !
 
-## Heading {MD026} ?
+## Heading?
 
 ## Heading/Full-Width {MD026} 。
 
@@ -22,11 +22,11 @@
 
 ## Heading/Full-Width {MD026} ！
 
-## Heading/Full-Width {MD026} ？
+## Heading/Full-Width？
 
 <!-- markdownlint-disable heading-style -->
 
-## Heading {MD026} alternate ? ##
+## Heading {MD026} alternate ! ##
 
-Heading {MD026} alternate too ?
+Heading {MD026} alternate too !
 -------------------------------

test/heading_trailing_punctuation_customized.json

@@ -1,6 +1,6 @@
 {
   "default": true,
   "MD026": {
-    "punctuation": ".,;:!]"
+    "punctuation": ".,;:?]"
   }
 }

test/heading_trailing_punctuation_customized.md

@@ -2,15 +2,15 @@
 
 ## Heading 2 {MD026},
 
-## Heading 3 {MD026}!
+## Heading 3!
 
 ## Heading 4 {MD026}:
 
 ## Heading 5 {MD026};
 
-## Heading 6?
+## Heading 6 {MD026}?
 
 ## Heading 7 {MD026}]
 
-The rule has been customized to allow question marks while disallowing
+The rule has been customized to allow exclamation point while disallowing
 everything else.