feat: add options.appendIdToHeading, set it to false to prevent id …

…attribute appended

README.md

@@ -211,6 +211,12 @@ documents on the same page.
 
 Allows you to customize the slug function that create ids from string.
 
+#### `appendIdToHeading`
+
+(default: `true`)
+
+To make anchor links work, should append id attribute to headings, but if other plugins have already done this, you can turn it off.
+
 Ex:
 ```js
    // ...

src/__tests__/toc.js

@@ -33,6 +33,24 @@ test("markdown-it-toc-and-anchor toc", t => {
     "should work with soft breaks"
   );
 
+  t.is(
+    mdIt(
+      `@[toc]
+# Heading`,
+      {
+        toc: true,
+        appendIdToHeading: false
+      }
+    ),
+    `<p><ul class="markdownIt-TOC">
+<li><a href="#heading">Heading</a></li>
+</ul>
+</p>
+<h1>Heading</h1>\n`,
+    "should not add id attribute if `appendIdToHeading` is falsy"
+  );
+
+
   t.is(
     mdIt(
       `test
@@ -422,4 +440,5 @@ resetIds is true and toc is true`
 same names on different renderings with the same markdownIt instance when
 resetIds is false and toc is true`
   );
+
 });

src/index.js

@@ -157,6 +157,7 @@ export default function(md, options) {
     anchorLinkSpace: true,
     anchorLinkSymbolClassName: null,
     wrapHeadingTextInAnchor: false,
+    appendIdToHeading: true,
     ...options
   };
 
@@ -277,26 +278,28 @@ export default function(md, options) {
     return true;
   });
 
-  const originalHeadingOpen =
-    md.renderer.rules.heading_open ||
-    function(...args) {
-      const [tokens, idx, options, , self] = args;
-      return self.renderToken(tokens, idx, options);
-    };
+  if (options.appendIdToHeading) {
+    const originalHeadingOpen =
+      md.renderer.rules.heading_open ||
+      function(...args) {
+        const [tokens, idx, options, , self] = args;
+        return self.renderToken(tokens, idx, options);
+      };
 
-  md.renderer.rules.heading_open = function(...args) {
-    const [tokens, idx, , ,] = args;
+    md.renderer.rules.heading_open = function(...args) {
+      const [tokens, idx, , ,] = args;
 
-    const attrs = (tokens[idx].attrs = tokens[idx].attrs || []);
-    const anchor = tokens[idx + 1]._tocAnchor;
-    attrs.push(["id", anchor]);
+      const attrs = (tokens[idx].attrs = tokens[idx].attrs || []);
+      const anchor = tokens[idx + 1]._tocAnchor;
+      attrs.push(["id", anchor]);
 
-    if (options.anchorLink) {
-      renderAnchorLink(anchor, options, ...args);
-    }
+      if (options.anchorLink) {
+        renderAnchorLink(anchor, options, ...args);
+      }
 
-    return originalHeadingOpen.apply(this, args);
-  };
+      return originalHeadingOpen.apply(this, args);
+    };
+  }
 
   md.renderer.rules.toc_open = () => "";
   md.renderer.rules.toc_close = () => "";