Reimplement MD003/heading-style using micromark tokens.

lib/md003.js

@@ -2,8 +2,9 @@
 
 "use strict";
 
-const { addErrorDetailIf, filterTokens, headingStyleFor } =
-  require("../helpers");
+const { addErrorDetailIf } = require("../helpers");
+const { filterByTypes, getHeadingLevel, getHeadingStyle, inHtmlFlow } =
+  require("../helpers/micromark.cjs");
 
 // eslint-disable-next-line jsdoc/valid-types
 /** @type import("./markdownlint").Rule */
@@ -11,16 +12,20 @@ module.exports = {
   "names": [ "MD003", "heading-style" ],
   "description": "Heading style",
   "tags": [ "headings" ],
-  "parser": "markdownit",
+  "parser": "micromark",
   "function": function MD003(params, onError) {
     let style = String(params.config.style || "consistent");
-    filterTokens(params, "heading_open", function forToken(token) {
-      const styleForToken = headingStyleFor(token);
+    const headings = filterByTypes(
+      params.parsers.micromark.tokens,
+      [ "atxHeading", "setextHeading" ]
+    );
+    for (const heading of headings) {
+      const styleForToken = getHeadingStyle(heading);
       if (style === "consistent") {
         style = styleForToken;
       }
-      if (styleForToken !== style) {
-        const h12 = /h[12]/.test(token.tag);
+      if ((styleForToken !== style) && !inHtmlFlow(heading)) {
+        const h12 = getHeadingLevel(heading) <= 2;
         const setextWithAtx =
           (style === "setext_with_atx") &&
             ((h12 && (styleForToken === "setext")) ||
@@ -36,10 +41,14 @@ module.exports = {
           } else if (style === "setext_with_atx_closed") {
             expected = h12 ? "setext" : "atx_closed";
           }
-          addErrorDetailIf(onError, token.lineNumber,
-            expected, styleForToken);
+          addErrorDetailIf(
+            onError,
+            heading.startLine,
+            expected,
+            styleForToken
+          );
         }
       }
-    });
+    }
   }
 };