Update MD053/link-image-reference-definitions to handle references within references (i.e., Pandoc-style footnotes), verify Pandoc footnote indent is not treated as comment when markdown-it-footnote plugin is used (fixes #599).

demo/markdownlint-browser.js

@@ -802,7 +802,8 @@ function getReferenceLinkImageData(lineMetadata) {
                 else {
                     definitions.set(label, lineIndex);
                 }
-                exclusions.push([0, lineOffsets[lineIndex], line.length]);
+                const labelLength = linkReferenceDefinitionMatch[0].length;
+                exclusions.push([0, lineOffsets[lineIndex], labelLength]);
             }
         }
     });

helpers/helpers.js

@@ -836,7 +836,8 @@ function getReferenceLinkImageData(lineMetadata) {
         } else {
           definitions.set(label, lineIndex);
         }
-        exclusions.push([ 0, lineOffsets[lineIndex], line.length ]);
+        const labelLength = linkReferenceDefinitionMatch[0].length;
+        exclusions.push([ 0, lineOffsets[lineIndex], labelLength ]);
       }
     }
   });

package.json

@@ -69,6 +69,7 @@
     "eslint-plugin-unicorn": "44.0.2",
     "globby": "13.1.2",
     "js-yaml": "4.1.0",
+    "markdown-it-footnote": "3.0.3",
     "markdown-it-for-inline": "0.1.1",
     "markdown-it-sub": "1.0.0",
     "markdown-it-sup": "1.0.0",

test/markdownlint-test.js

@@ -6,6 +6,7 @@ const fs = require("node:fs");
 const path = require("node:path");
 const jsYaml = require("js-yaml");
 const md = require("markdown-it")();
+const pluginFootnote = require("markdown-it-footnote");
 const pluginInline = require("markdown-it-for-inline");
 const pluginSub = require("markdown-it-sub");
 const pluginSup = require("markdown-it-sup");
@@ -1254,6 +1255,32 @@ test("texmath test files with texmath plugin", (t) => new Promise((resolve) => {
   });
 }));
 
+test("Pandoc footnote via footnote plugin", (t) => new Promise((resolve) => {
+  t.plan(2);
+  markdownlint({
+    "strings": {
+      "string":
+`# Heading
+
+Text with: [^footnote]
+
+[^footnote]: Footnote text on multiple
+
+    lines including a [reference][]
+
+[reference]: https://example.com
+`
+    },
+    "markdownItPlugins": [ [ pluginFootnote ] ],
+    "resultVersion": 0
+  }, (err, actual) => {
+    t.falsy(err);
+    const expected = { "string": {} };
+    t.deepEqual(actual, expected, "Unexpected issues.");
+    resolve();
+  });
+}));
+
 test("token-map-spans", (t) => {
   t.plan(38);
   const options = {

test/pandoc-footnotes.md

@@ -0,0 +1,47 @@
+# Pandoc Footnotes
+
+> Examples taken from [GitHub issue 599](https://github.com/DavidAnson/markdownlint/issues/599)
+
+## Example with Pandoc Footnotes
+
+A sentence with footnotes: [^1] [^2]
+A sentence with named footnotes: [^name] [^name2]
+A sentence with a link reference: [Pandoc's User Guide][Pandoc1]
+
+[^1]: I am a footnote!
+[^2]: I reference a [PCW][PCW1] article!
+[^name]: I am a footnote with name!
+[^name2]: I am also a named footnote! I also reference the [PCW][PCW1] article!
+
+[PCW1]: https://www.example.com/article.html
+[Pandoc1]: https://pandoc.org/MANUAL.html#extension-footnotes
+
+## Example with Long Pandoc Footnotes
+
+A sentence with a long footnotes: [^long] [^longer] [^longest]
+
+[^long]: I am a long footnote!
+    I don't do any harm :)
+[^longer]: I am a longer footnote. I do reference the [PCW][PCW2] article.
+    I do harm. Though, not here: [Pandoc's User Guide][Pandoc2]
+[^longest]: I am the longest footnote. I also reference the [PCW][PCW2] article.
+
+    I am a harmful new block of text: [Another][Another2]
+
+> The previous line of text is treated by CommonMark as an indented code block.
+> To handle it as a Pandoc footnote, consider the `markdown-it-footnote` plugin.
+
+[PCW2]: https://www.example.com/article.html
+[Pandoc2]: https://pandoc.org/MANUAL.html#extension-footnotes
+[Another2]: https://www.example.com/another.{MD053}.html
+
+## GitHub Footnotes
+
+Sample footnotes [^3] [^note3]
+
+[^3]: A line
+  A new line
+
+[^note3]:
+    I am a new block of text
+    With a new line as well

test/reference-links-and-images.md

@@ -228,3 +228,11 @@ Not flagged due to ambiguity: [ignored]
 Unmatched [ in text
 
 Hidden reference: [hidden][] {MD052}
+
+## Link references inside reference definitions
+
+Text with a [^footnote] in it
+
+[^footnote]: Footnote with an [embedded-reference][] in it
+
+[embedded-reference]: https://example.com/embedded-reference

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

@@ -32084,6 +32084,80 @@ Generated by [AVA](https://avajs.dev).
       `,
     }
 
+## pandoc-footnotes.md
+
+> Snapshot 1
+
+    {
+      errors: [
+        {
+          errorContext: '[Another2]: https://www.exampl...',
+          errorDetail: 'Unused link or image reference definition: "another2"',
+          errorRange: [
+            1,
+            56,
+          ],
+          fixInfo: {
+            deleteCount: -1,
+          },
+          lineNumber: 36,
+          ruleDescription: 'Link and image reference definitions should be needed',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/Rules.md#md053',
+          ruleNames: [
+            'MD053',
+            'link-image-reference-definitions',
+          ],
+        },
+      ],
+      fixed: `# Pandoc Footnotes␊
+      ␊
+      > Examples taken from [GitHub issue 599](https://github.com/DavidAnson/markdownlint/issues/599)␊
+      ␊
+      ## Example with Pandoc Footnotes␊
+      ␊
+      A sentence with footnotes: [^1] [^2]␊
+      A sentence with named footnotes: [^name] [^name2]␊
+      A sentence with a link reference: [Pandoc's User Guide][Pandoc1]␊
+      ␊
+      [^1]: I am a footnote!␊
+      [^2]: I reference a [PCW][PCW1] article!␊
+      [^name]: I am a footnote with name!␊
+      [^name2]: I am also a named footnote! I also reference the [PCW][PCW1] article!␊
+      ␊
+      [PCW1]: https://www.example.com/article.html␊
+      [Pandoc1]: https://pandoc.org/MANUAL.html#extension-footnotes␊
+      ␊
+      ## Example with Long Pandoc Footnotes␊
+      ␊
+      A sentence with a long footnotes: [^long] [^longer] [^longest]␊
+      ␊
+      [^long]: I am a long footnote!␊
+          I don't do any harm :)␊
+      [^longer]: I am a longer footnote. I do reference the [PCW][PCW2] article.␊
+          I do harm. Though, not here: [Pandoc's User Guide][Pandoc2]␊
+      [^longest]: I am the longest footnote. I also reference the [PCW][PCW2] article.␊
+      ␊
+          I am a harmful new block of text: [Another][Another2]␊
+      ␊
+      > The previous line of text is treated by CommonMark as an indented code block.␊
+      > To handle it as a Pandoc footnote, consider the \`markdown-it-footnote\` plugin.␊
+      ␊
+      [PCW2]: https://www.example.com/article.html␊
+      [Pandoc2]: https://pandoc.org/MANUAL.html#extension-footnotes␊
+      ␊
+      ## GitHub Footnotes␊
+      ␊
+      Sample footnotes [^3] [^note3]␊
+      ␊
+      [^3]: A line␊
+        A new line␊
+      ␊
+      [^note3]:␊
+          I am a new block of text␊
+          With a new line as well␊
+      `,
+    }
+
 ## proper-names-alternate.md
 
 > Snapshot 1
@@ -34592,6 +34666,14 @@ Generated by [AVA](https://avajs.dev).
       Unmatched [ in text␊
       ␊
       Hidden reference: [hidden][] {MD052}␊
+      ␊
+      ## Link references inside reference definitions␊
+      ␊
+      Text with a [^footnote] in it␊
+      ␊
+      [^footnote]: Footnote with an [embedded-reference][] in it␊
+      ␊
+      [embedded-reference]: https://example.com/embedded-reference␊
       `,
     }