Update MD040/fenced-code-language to add language_only parameter to reject extra data in info string.

demo/markdownlint-browser.js

@@ -4176,6 +4176,7 @@ module.exports = {
     "function": function MD040(params, onError) {
         let allowed = params.config.allowed_languages;
         allowed = Array.isArray(allowed) ? allowed : [];
+        const languageOnly = !!params.config.language_only;
         filterTokens(params, "fence", function forToken(token) {
             const lang = token.info.trim().split(/\s+/u).shift();
             if (lang === "") {
@@ -4184,6 +4185,9 @@ module.exports = {
             else if ((allowed.length > 0) && !allowed.includes(lang)) {
                 addError(onError, token.lineNumber, `"${lang}" is not allowed`);
             }
+            if (languageOnly && (token.info !== lang)) {
+                addError(onError, token.lineNumber, `Info string contains more than language: "${token.info}"`);
+            }
         });
     }
 };

doc-build/md040.md

@@ -29,6 +29,13 @@ You can configure the `allowed_languages` parameter to specify a list of
 languages code blocks could use. Languages are case sensitive. The default value
 is `[]` which means any language specifier is valid.
 
+You can prevent extra data from being present in the info string of fenced code
+blocks. To do so, set the `language_only` parameter to `true`.
+
+<!-- markdownlint-disable-next-line no-space-in-code -->
+Info strings with leading/trailing whitespace (ex: `js `) or other content (ex:
+`ruby startline=3`) will trigger this rule.
+
 Rationale: Specifying a language improves content rendering by using the
 correct syntax highlighting for code. More information:
 <https://cirosantilli.com/markdown-style-guide#option-code-fenced>.

doc/Rules.md

@@ -1623,6 +1623,7 @@ Aliases: `fenced-code-language`
 Parameters:
 
 * `allowed_languages`: List of languages (`string[]`, default `[]`)
+* `language_only`: Require language only (`boolean`, default `false`)
 
 This rule is triggered when fenced code blocks are used, but a language isn't
 specified:
@@ -1655,6 +1656,13 @@ You can configure the `allowed_languages` parameter to specify a list of
 languages code blocks could use. Languages are case sensitive. The default value
 is `[]` which means any language specifier is valid.
 
+You can prevent extra data from being present in the info string of fenced code
+blocks. To do so, set the `language_only` parameter to `true`.
+
+<!-- markdownlint-disable-next-line no-space-in-code -->
+Info strings with leading/trailing whitespace (ex: `js `) or other content (ex:
+`ruby startline=3`) will trigger this rule.
+
 Rationale: Specifying a language improves content rendering by using the
 correct syntax highlighting for code. More information:
 <https://cirosantilli.com/markdown-style-guide#option-code-fenced>.

doc/md040.md

@@ -7,6 +7,7 @@ Aliases: `fenced-code-language`
 Parameters:
 
 * `allowed_languages`: List of languages (`string[]`, default `[]`)
+* `language_only`: Require language only (`boolean`, default `false`)
 
 This rule is triggered when fenced code blocks are used, but a language isn't
 specified:
@@ -39,6 +40,13 @@ You can configure the `allowed_languages` parameter to specify a list of
 languages code blocks could use. Languages are case sensitive. The default value
 is `[]` which means any language specifier is valid.
 
+You can prevent extra data from being present in the info string of fenced code
+blocks. To do so, set the `language_only` parameter to `true`.
+
+<!-- markdownlint-disable-next-line no-space-in-code -->
+Info strings with leading/trailing whitespace (ex: `js `) or other content (ex:
+`ruby startline=3`) will trigger this rule.
+
 Rationale: Specifying a language improves content rendering by using the
 correct syntax highlighting for code. More information:
 <https://cirosantilli.com/markdown-style-guide#option-code-fenced>.

lib/md040.js

@@ -11,6 +11,8 @@ module.exports = {
   "function": function MD040(params, onError) {
     let allowed = params.config.allowed_languages;
     allowed = Array.isArray(allowed) ? allowed : [];
+    const languageOnly = !!params.config.language_only;
+
     filterTokens(params, "fence", function forToken(token) {
       const lang = token.info.trim().split(/\s+/u).shift();
       if (lang === "") {
@@ -22,6 +24,14 @@ module.exports = {
           `"${lang}" is not allowed`
         );
       }
+
+      if (languageOnly && (token.info !== lang)) {
+        addError(
+          onError,
+          token.lineNumber,
+          `Info string contains more than language: "${token.info}"`
+        );
+      }
     });
   }
 };

schema/.markdownlint.jsonc

@@ -209,7 +209,9 @@
   // MD040/fenced-code-language - Fenced code blocks should have a language specified
   "MD040": {
     // List of languages
-    "allowed_languages": []
+    "allowed_languages": [],
+    // Require language only
+    "language_only": false
   },
 
   // MD041/first-line-heading/first-line-h1 - First line in a file should be a top-level heading

schema/.markdownlint.yaml

@@ -191,6 +191,8 @@ MD039: true
 MD040:
   # List of languages
   allowed_languages: []
+  # Require language only
+  language_only: false
 
 # MD041/first-line-heading/first-line-h1 - First line in a file should be a top-level heading
 MD041:

schema/build-config-schema.js

@@ -356,6 +356,11 @@ for (const rule of rules) {
             "type": "string"
           },
           "default": []
+        },
+        "language_only": {
+          "description": "Require language only",
+          "type": "boolean",
+          "default": false
         }
       };
       break;

schema/markdownlint-config-schema.json

@@ -682,6 +682,11 @@
             "type": "string"
           },
           "default": []
+        },
+        "language_only": {
+          "description": "Require language only",
+          "type": "boolean",
+          "default": false
         }
       },
       "additionalProperties": false

test/md040-language_only.json

@@ -0,0 +1,6 @@
+{
+  "MD040": {
+    "allowed_languages": ["html", "css"],
+    "language_only": true
+  }
+}

test/md040-language_only.md

@@ -0,0 +1,25 @@
+# md040-language_only.md
+
+Fence code block information with leading whitespace:
+
+```  html
+<h1>markdownlint</h1> {MD040:5}
+```
+
+Fence code block information with trailing whitespace:
+
+```css 
+body {} {MD040:11} {MD009:11}
+```
+
+Fence code block information with extra data:
+
+```html version=5
+<title>MarkdownLint</title> {MD040:17}
+```
+
+Fence code block information without whitespaces and extra data:
+
+```css
+a {}
+```

test/snapshots/markdownlint-test-scenarios.js.md

@@ -29553,6 +29553,99 @@ Generated by [AVA](https://avajs.dev).
       `,
     }
 
+## md040-language_only.md
+
+> Snapshot 1
+
+    {
+      errors: [
+        {
+          errorContext: null,
+          errorDetail: 'Expected: 0 or 2; Actual: 1',
+          errorRange: [
+            7,
+            1,
+          ],
+          fixInfo: {
+            deleteCount: 1,
+            editColumn: 7,
+          },
+          lineNumber: 11,
+          ruleDescription: 'Trailing spaces',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md009.md',
+          ruleNames: [
+            'MD009',
+            'no-trailing-spaces',
+          ],
+        },
+        {
+          errorContext: null,
+          errorDetail: 'Info string contains more than language: "  html"',
+          errorRange: null,
+          fixInfo: null,
+          lineNumber: 5,
+          ruleDescription: 'Fenced code blocks should have a language specified',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md040.md',
+          ruleNames: [
+            'MD040',
+            'fenced-code-language',
+          ],
+        },
+        {
+          errorContext: null,
+          errorDetail: 'Info string contains more than language: "css "',
+          errorRange: null,
+          fixInfo: null,
+          lineNumber: 11,
+          ruleDescription: 'Fenced code blocks should have a language specified',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md040.md',
+          ruleNames: [
+            'MD040',
+            'fenced-code-language',
+          ],
+        },
+        {
+          errorContext: null,
+          errorDetail: 'Info string contains more than language: "html version=5"',
+          errorRange: null,
+          fixInfo: null,
+          lineNumber: 17,
+          ruleDescription: 'Fenced code blocks should have a language specified',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md040.md',
+          ruleNames: [
+            'MD040',
+            'fenced-code-language',
+          ],
+        },
+      ],
+      fixed: `# md040-language_only.md␊
+      ␊
+      Fence code block information with leading whitespace:␊
+      ␊
+      \`\`\`  html␊
+      <h1>markdownlint</h1> {MD040:5}␊
+      \`\`\`␊
+      ␊
+      Fence code block information with trailing whitespace:␊
+      ␊
+      \`\`\`css␊
+      body {} {MD040:11} {MD009:11}␊
+      \`\`\`␊
+      ␊
+      Fence code block information with extra data:␊
+      ␊
+      \`\`\`html version=5␊
+      <title>MarkdownLint</title> {MD040:17}␊
+      \`\`\`␊
+      ␊
+      Fence code block information without whitespaces and extra data:␊
+      ␊
+      \`\`\`css␊
+      a {}␊
+      \`\`\`␊
+      `,
+    }
+
 ## md041-ignore-leading-comments-combined.md
 
 > Snapshot 1