Create helper function for subgraph title margin fetching.

packages/mermaid/src/utils.spec.ts

@@ -1,5 +1,7 @@
 import { vi } from 'vitest';
 import utils, { calculatePoint, cleanAndMerge, detectDirective } from './utils.js';
+import { getSubGraphTitleMargins } from './utils/getSubGraphTitleMargins.js';
+import * as configApi from './config.js';
 import assignWithDepth from './assignWithDepth.js';
 import { detectType } from './diagram-api/detectType.js';
 import { addDiagrams } from './diagram-api/diagram-orchestration.js';
@@ -593,4 +595,24 @@ describe('calculatePoint', () => {
       'Could not find a suitable point for the given distance'
     );
   });
+
+  describe('getSubGraphTitleMargins', () => {
+    it('should get subgraph title margins after config has been set', () => {
+      const config_0 = {
+        flowchart: {
+          subGraphTitleMargin: {
+            top: 10,
+            bottom: 5,
+          },
+        },
+      };
+
+      configApi.setSiteConfig(config_0);
+      expect(getSubGraphTitleMargins()).toEqual({
+        subGraphTitleTopMargin: 10,
+        subGraphTitleBottomMargin: 5,
+        subGraphTitleTotalMargin: 15,
+      });
+    });
+  });
 });

packages/mermaid/src/utils/getSubGraphTitleMargins.ts

@@ -0,0 +1,17 @@
+import { getConfig } from '../diagram-api/diagramAPI.js';
+
+export const getSubGraphTitleMargins = (): {
+  subGraphTitleTopMargin: number;
+  subGraphTitleBottomMargin: number;
+  subGraphTitleTotalMargin: number;
+} => {
+  const subGraphTitleTopMargin = getConfig().flowchart?.subGraphTitleMargin?.top || 0;
+  const subGraphTitleBottomMargin = getConfig().flowchart?.subGraphTitleMargin?.bottom || 0;
+  const subGraphTitleTotalMargin = subGraphTitleTopMargin + subGraphTitleBottomMargin;
+
+  return {
+    subGraphTitleTopMargin,
+    subGraphTitleBottomMargin,
+    subGraphTitleTotalMargin,
+  };
+};