Merge pull request #5065 from mermaid-js/5064_EdgeOffsetEdgeCase

fix: #5064 Handle case when line has only one point

.vite/build.ts

@@ -117,6 +117,9 @@ export const getBuildConfig = ({ minify, core, watch, entryName }: BuildOptions)
         output,
       },
     },
+    define: {
+      'import.meta.vitest': 'undefined',
+    },
     resolve: {
       extensions: [],
     },

cypress/integration/rendering/flowchart-v2.spec.js

@@ -729,6 +729,18 @@ A ~~~ B
       {}
     );
   });
+
+  it('5064: Should render when subgraph child has links to outside node and subgraph', () => {
+    imgSnapshotTest(
+      `flowchart TB
+    Out --> In
+    subgraph Sub
+      In
+    end
+    Sub --> In`
+    );
+  });
+
   describe('Markdown strings flowchart (#4220)', () => {
     describe('html labels', () => {
       it('With styling and classes', () => {

packages/mermaid/src/mermaid.spec.ts

@@ -2,7 +2,7 @@ import mermaid from './mermaid.js';
 import { mermaidAPI } from './mermaidAPI.js';
 import './diagram-api/diagram-orchestration.js';
 import { addDiagrams } from './diagram-api/diagram-orchestration.js';
-import { beforeAll, describe, it, expect, vi } from 'vitest';
+import { beforeAll, describe, it, expect, vi, afterEach } from 'vitest';
 import type { DiagramDefinition } from './diagram-api/types.js';
 
 beforeAll(async () => {

packages/mermaid/src/utils/lineWithOffset.ts

@@ -19,9 +19,12 @@ const markerOffsets = {
  * @returns The angle, deltaX and deltaY
  */
 function calculateDeltaAndAngle(
-  point1: Point | [number, number],
-  point2: Point | [number, number]
+  point1?: Point | [number, number],
+  point2?: Point | [number, number]
 ): { angle: number; deltaX: number; deltaY: number } {
+  if (point1 === undefined || point2 === undefined) {
+    return { angle: 0, deltaX: 0, deltaY: 0 };
+  }
   point1 = pointTransformer(point1);
   point2 = pointTransformer(point2);
   const [x1, y1] = [point1.x, point1.y];
@@ -90,3 +93,44 @@ export const getLineFunctionsWithOffset = (
     },
   };
 };
+
+if (import.meta.vitest) {
+  const { it, expect, describe } = import.meta.vitest;
+  describe('calculateDeltaAndAngle', () => {
+    it('should calculate the angle and deltas between two points', () => {
+      expect(calculateDeltaAndAngle([0, 0], [0, 1])).toStrictEqual({
+        angle: 1.5707963267948966,
+        deltaX: 0,
+        deltaY: 1,
+      });
+      expect(calculateDeltaAndAngle([1, 0], [0, -1])).toStrictEqual({
+        angle: 0.7853981633974483,
+        deltaX: -1,
+        deltaY: -1,
+      });
+      expect(calculateDeltaAndAngle({ x: 1, y: 0 }, [0, -1])).toStrictEqual({
+        angle: 0.7853981633974483,
+        deltaX: -1,
+        deltaY: -1,
+      });
+      expect(calculateDeltaAndAngle({ x: 1, y: 0 }, { x: 1, y: 0 })).toStrictEqual({
+        angle: NaN,
+        deltaX: 0,
+        deltaY: 0,
+      });
+    });
+
+    it('should calculate the angle and deltas if one point in undefined', () => {
+      expect(calculateDeltaAndAngle(undefined, [0, 1])).toStrictEqual({
+        angle: 0,
+        deltaX: 0,
+        deltaY: 0,
+      });
+      expect(calculateDeltaAndAngle([0, 1], undefined)).toStrictEqual({
+        angle: 0,
+        deltaX: 0,
+        deltaY: 0,
+      });
+    });
+  });
+}

packages/mermaid/tsconfig.json

@@ -2,7 +2,8 @@
   "extends": "../../tsconfig.json",
   "compilerOptions": {
     "rootDir": "./src",
-    "outDir": "./dist"
+    "outDir": "./dist",
+    "types": ["vitest/importMeta", "vitest/globals"]
   },
   "include": ["./src/**/*.ts", "./package.json"]
 }