[ML] Transforms: Data grid fixes. (#59538)

- Fixes data grid schemas to avoid crashing the page.
- Fixes date formatting.
- Uses data grid for preview table in transform list.

x-pack/plugins/transform/common/utils/object_utils.test.ts

@@ -0,0 +1,70 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { getNestedProperty } from './object_utils';
+
+describe('object_utils', () => {
+  test('getNestedProperty()', () => {
+    const testObj = {
+      the: {
+        nested: {
+          value: 'the-nested-value',
+        },
+      },
+    };
+
+    const falseyObj = {
+      the: {
+        nested: {
+          value: false,
+        },
+        other_nested: {
+          value: 0,
+        },
+      },
+    };
+
+    const test1 = getNestedProperty(testObj, 'the');
+    expect(typeof test1).toBe('object');
+    expect(Object.keys(test1)).toStrictEqual(['nested']);
+
+    const test2 = getNestedProperty(testObj, 'the$');
+    expect(typeof test2).toBe('undefined');
+
+    const test3 = getNestedProperty(testObj, 'the$', 'the-default-value');
+    expect(typeof test3).toBe('string');
+    expect(test3).toBe('the-default-value');
+
+    const test4 = getNestedProperty(testObj, 'the.neSted');
+    expect(typeof test4).toBe('undefined');
+
+    const test5 = getNestedProperty(testObj, 'the.nested');
+    expect(typeof test5).toBe('object');
+    expect(Object.keys(test5)).toStrictEqual(['value']);
+
+    const test6 = getNestedProperty(testObj, 'the.nested.vaLue');
+    expect(typeof test6).toBe('undefined');
+
+    const test7 = getNestedProperty(testObj, 'the.nested.value');
+    expect(typeof test7).toBe('string');
+    expect(test7).toBe('the-nested-value');
+
+    const test8 = getNestedProperty(testObj, 'the.nested.value.doesntExist');
+    expect(typeof test8).toBe('undefined');
+
+    const test9 = getNestedProperty(testObj, 'the.nested.value.doesntExist', 'the-default-value');
+    expect(typeof test9).toBe('string');
+    expect(test9).toBe('the-default-value');
+
+    const test10 = getNestedProperty(falseyObj, 'the.nested.value');
+    expect(typeof test10).toBe('boolean');
+    expect(test10).toBe(false);
+
+    const test11 = getNestedProperty(falseyObj, 'the.other_nested.value');
+    expect(typeof test11).toBe('number');
+    expect(test11).toBe(0);
+  });
+});

x-pack/plugins/transform/common/utils/object_utils.ts

@@ -11,5 +11,9 @@ export const getNestedProperty = (
   accessor: string,
   defaultValue?: any
 ) => {
-  return accessor.split('.').reduce((o, i) => o?.[i], obj) || defaultValue;
+  const value = accessor.split('.').reduce((o, i) => o?.[i], obj);
+
+  if (value === undefined) return defaultValue;
+
+  return value;
 };