Merge pull request #7099 from mermaid-js/fix/mindmap-level-node-rendering

7000: Fix mindmap rendering issue when Level 2 nodes exceed 11

.changeset/wide-lines-trade.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Mindmap rendering issue when the number of Level 2 nodes exceeds 11

cypress/integration/rendering/mindmap.spec.ts

@@ -247,5 +247,31 @@ root
       );
     });
   });
+  describe('Level 2 nodes exceeding 11', () => {
+    it('should render all Level 2 nodes correctly when there are more than 11', () => {
+      imgSnapshotTest(
+        `mindmap
+root
+  Node1
+  Node2
+  Node3
+  Node4
+  Node5
+  Node6
+  Node7
+  Node8
+  Node9
+  Node10
+  Node11
+  Node12
+  Node13
+  Node14
+  Node15`,
+        {},
+        undefined,
+        shouldHaveRoot
+      );
+    });
+  });
   /* The end */
 });

packages/mermaid/src/diagrams/mindmap/mindmapDb.getData.test.ts

@@ -293,5 +293,37 @@ describe('MindmapDb getData function', () => {
       expect(edgeA1_aaa.section).toBe(1);
       expect(edgeA_a2.section).toBe(2);
     });
+
+    it('should wrap section numbers when there are more than 11 level 2 nodes', () => {
+      db.addNode(0, 'root', 'Example', 0);
+
+      for (let i = 1; i <= 15; i++) {
+        db.addNode(1, `child${i}`, `${i}`, 0);
+      }
+
+      const result = db.getData();
+
+      expect(result.nodes).toHaveLength(16);
+
+      const child1 = result.nodes.find((n) => n.label === '1') as MindmapLayoutNode;
+      const child11 = result.nodes.find((n) => n.label === '11') as MindmapLayoutNode;
+      const child12 = result.nodes.find((n) => n.label === '12') as MindmapLayoutNode;
+      const child13 = result.nodes.find((n) => n.label === '13') as MindmapLayoutNode;
+      const child14 = result.nodes.find((n) => n.label === '14') as MindmapLayoutNode;
+      const child15 = result.nodes.find((n) => n.label === '15') as MindmapLayoutNode;
+
+      expect(child1.section).toBe(0);
+      expect(child11.section).toBe(10);
+
+      expect(child12.section).toBe(0);
+      expect(child13.section).toBe(1);
+      expect(child14.section).toBe(2);
+      expect(child15.section).toBe(3);
+
+      expect(child12.cssClasses).toBe('mindmap-node section-0');
+      expect(child13.cssClasses).toBe('mindmap-node section-1');
+      expect(child14.cssClasses).toBe('mindmap-node section-2');
+      expect(child15.cssClasses).toBe('mindmap-node section-3');
+    });
   });
 });

packages/mermaid/src/diagrams/mindmap/mindmapDb.ts

@@ -7,6 +7,7 @@ import type { MindmapNode } from './mindmapTypes.js';
 import defaultConfig from '../../defaultConfig.js';
 import type { LayoutData, Node, Edge } from '../../rendering-util/types.js';
 import { getUserDefinedConfig } from '../../config.js';
+import { MAX_SECTIONS } from './svgDraw.js';
 
 // Extend Node type for mindmap-specific properties
 export type MindmapLayoutNode = Node & {
@@ -203,7 +204,7 @@ export class MindmapDB {
     // For other nodes, inherit parent's section number
     if (node.children) {
       for (const [index, child] of node.children.entries()) {
-        const childSectionNumber = node.level === 0 ? index : sectionNumber;
+        const childSectionNumber = node.level === 0 ? index % (MAX_SECTIONS - 1) : sectionNumber;
         this.assignSections(child, childSectionNumber);
       }
     }

packages/mermaid/src/diagrams/mindmap/svgDraw.ts

@@ -5,7 +5,7 @@ import { parseFontSize } from '../../utils.js';
 import type { MermaidConfig } from '../../config.type.js';
 import type { MindmapDB } from './mindmapDb.js';
 
-const MAX_SECTIONS = 12;
+export const MAX_SECTIONS = 12;
 
 type ShapeFunction = (
   db: MindmapDB,