test(sankey): add test for data process

__tests__/unit/plots/sankey/index-spec.ts

@@ -121,6 +121,6 @@ describe('sankey', () => {
       y: [0.8358823529411765, 0.8358823529411765, 1, 1],
     });
 
-    // sankey.destroy();
+    sankey.destroy();
   });
 });

__tests__/unit/plots/sankey/util/data-spec.ts

@@ -0,0 +1,30 @@
+import { transformDataToSankey } from '../../../../../src/plots/sankey/util/data';
+
+describe('sankey util', () => {
+  it('transformDataToSankey', () => {
+    // @ts-ignore
+    expect(transformDataToSankey({})).toEqual({ nodes: [], links: [] });
+    // @ts-ignore
+    expect(transformDataToSankey(1)).toEqual({ nodes: [], links: [] });
+
+    expect(
+      transformDataToSankey(
+        [
+          { source: '杭州', target: '上海', value: 1 },
+          { source: '上海', target: '北京', value: 2 },
+          { source: '杭州', target: '北京', value: 3 },
+        ],
+        'source',
+        'target',
+        'value'
+      )
+    ).toEqual({
+      nodes: [{ name: '杭州' }, { name: '上海' }, { name: '北京' }],
+      links: [
+        { source: 0, target: 1, value: 1 },
+        { source: 1, target: 2, value: 2 },
+        { source: 0, target: 2, value: 3 },
+      ],
+    });
+  });
+});