[ML] Fix type guard and add jest tests.

Author: walterra

x-pack/plugins/transform/server/routes/api/transforms_nodes.test.ts

@@ -0,0 +1,32 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { isNodes } from './transforms_nodes';
+
+describe('Transform: Nodes API endpoint', () => {
+  test('isNodes()', () => {
+    expect(isNodes(undefined)).toBe(false);
+    expect(isNodes({})).toBe(false);
+    expect(isNodes({ nodeId: {} })).toBe(false);
+    expect(isNodes({ nodeId: { someAttribute: {} } })).toBe(false);
+    expect(isNodes({ nodeId: { attributes: {} } })).toBe(false);
+    expect(
+      isNodes({
+        nodeId1: { attributes: { someAttribute: true } },
+        nodeId2: { someAttribute: 'asdf' },
+      })
+    ).toBe(false);
+
+    expect(isNodes({ nodeId: { attributes: { someAttribute: true } } })).toBe(true);
+    expect(
+      isNodes({
+        nodeId1: { attributes: { someAttribute: true } },
+        nodeId2: { attributes: { 'transform.node': 'true' } },
+      })
+    ).toBe(true);
+  });
+});

x-pack/plugins/transform/server/routes/api/transforms_nodes.ts

@@ -15,20 +15,19 @@ import { wrapError, wrapEsError } from './error_utils';
 
 interface NodesAttributes {
   attributes: {
-    'transform.node': string;
+    'transform.node'?: string;
   };
 }
 type Nodes = Record<string, NodesAttributes>;
 
-const isNodes = (arg: unknown): arg is Nodes => {
+export const isNodes = (arg: unknown): arg is Nodes => {
   return (
     isPopulatedObject(arg) &&
     Object.values(arg).every(
       (node) =>
         isPopulatedObject(node) &&
         {}.hasOwnProperty.call(node, 'attributes') &&
-        isPopulatedObject(node.attributes) &&
-        {}.hasOwnProperty.call(node.attributes, 'transform.node')
+        isPopulatedObject(node.attributes)
     )
   );
 };