docs: add sankey component documentation (#2989)

Author: lxfu1

packages/plots/src/core/plots/sankey/adaptor.ts

@@ -1,42 +1,42 @@
 import { mark } from '../../adaptor';
 import type { Adaptor } from '../../types';
-import { flow, get, isArray, set, transformOptions } from '../../utils';
+import { flow, get, isArray, set, dataTransform, transformOptions } from '../../utils';
 import type { SankeyOptions } from './type';
 
 type Params = Adaptor<SankeyOptions>;
 
+const defaultTransform = (params: Params) => {
+  const { options } = params;
+  const { data } = options;
+  const transformLinks = [
+    {
+      type: 'custom',
+      callback: (datum) => ({ links: datum }),
+    },
+  ];
+  if (isArray(data)) {
+    if (data.length > 0) {
+      set(options, 'data', {
+        value: data,
+        transform: transformLinks,
+      });
+    } else {
+      delete options.children;
+    }
+  } else if (get(data, 'type') === 'fetch' && get(data, 'value')) {
+    const transform = get(data, 'transform');
+    if (!isArray(transform)) {
+      set(data, 'transform', transformLinks);
+    }
+  }
+  return params;
+};
+
 /**
  * @param chart
  * @param options
  */
 export function adaptor(params: Params) {
-  const dataTransform = (params: Params) => {
-    const { options } = params;
-    const { data } = options;
-    const defaultTransform = [
-      {
-        type: 'custom',
-        callback: (datum) => ({ links: datum }),
-      },
-    ];
-    if (isArray(data)) {
-      if (data.length > 0) {
-        set(options, 'data', {
-          value: data,
-          transform: defaultTransform,
-        });
-      } else {
-        delete options.children;
-      }
-    } else if (get(data, 'type') === 'fetch' && get(data, 'value')) {
-      const transform = get(data, 'transform');
-      if (isArray(transform)) {
-        set(data, 'transform', transform.concat(defaultTransform));
-      } else {
-        set(data, 'transform', defaultTransform);
-      }
-    }
-    return params;
-  };
-  return flow(dataTransform, mark, transformOptions)(params);
+
+  return flow(dataTransform, defaultTransform, mark, transformOptions)(params);
 }