Apply non-markdown label change for subgroups

cypress/integration/rendering/flowchart.spec.js

@@ -993,4 +993,29 @@ flowchart TB
       }
     );
   });
+  it('69: should render subgraphs with adhoc list headings', () => {
+    imgSnapshotTest(
+      `
+    graph TB
+      subgraph "1. first"
+        a1-->a2
+      end
+      subgraph 2. second
+        b1-->b2
+      end
+      `,
+      { fontFamily: 'courier' }
+    );
+  });
+  it('70: should render subgraphs with markdown headings', () => {
+    imgSnapshotTest(
+      `
+    graph TB
+      subgraph "\`**strong**\`"
+        a1-->a2
+      end
+      `,
+      { fontFamily: 'courier' }
+    );
+  });
 });

packages/mermaid/src/diagrams/flowchart/flowDb.ts

@@ -1101,6 +1101,7 @@ You have to call mermaid.initialize.`
         id: subGraph.id,
         label: subGraph.title,
         labelStyle: '',
+        labelType: subGraph.labelType,
         parentId: parentDB.get(subGraph.id),
         padding: 8,
         cssCompiledStyles: this.getCompiledStyles(subGraph.classes),

packages/mermaid/src/rendering-util/rendering-elements/clusters.js

@@ -30,11 +30,17 @@ const rect = async (parent, node) => {
   // Create the label and insert it after the rect
   const labelEl = shapeSvg.insert('g').attr('class', 'cluster-label ');
 
-  const text = await createText(labelEl, node.label, {
-    style: node.labelStyle,
-    useHtmlLabels,
-    isNode: true,
-  });
+  let text;
+  if (node.labelType === 'markdown') {
+    text = await createText(labelEl, node.label, {
+      style: node.labelStyle,
+      useHtmlLabels,
+      isNode: true,
+    });
+  } else {
+    const labelElement = await createLabel(node.label, node.labelStyle, false, true);
+    text = labelEl.node()?.appendChild(labelElement);
+  }
 
   // Get the size of the label
   let bbox = text.getBBox();