editor: fix toc level mapping

packages/editor/src/utils/toc.ts

@@ -24,16 +24,35 @@ export type TOCItem = {
   top: number;
 };
 
+const levelsMap: Record<string, number> = {
+  H1: 1,
+  H2: 2,
+  H3: 3,
+  H4: 4,
+  H5: 5,
+  H6: 6
+};
+
 export function getTableOfContents(content: HTMLElement) {
   const tableOfContents: TOCItem[] = [];
-
+  let level = -1;
+  let prevHeading = 0;
   for (const heading of content.querySelectorAll<HTMLHeadingElement>(
     "h1, h2, h3, h4, h5, h6"
   )) {
-    const level = parseInt(heading.tagName[1]);
     const title = heading.textContent;
     const id = heading.dataset.blockId;
     if (!id || !title) continue;
+    const nodeName = heading.nodeName;
+    const currentHeading = levelsMap[nodeName];
+
+    level =
+      prevHeading < currentHeading
+        ? level + 1
+        : prevHeading > currentHeading
+        ? level - (prevHeading - currentHeading)
+        : level;
+    prevHeading = currentHeading;
 
     tableOfContents.push({
       level,
@@ -42,7 +61,6 @@ export function getTableOfContents(content: HTMLElement) {
       top: (heading as HTMLElement).offsetTop
     });
   }
-
   return tableOfContents;
 }