Form: fix get item by path (T1311534)

[anna-shakhova]

No description provided.

[Copilot]

Pull Request Overview

This PR fixes a bug in the Form component's itemOption method when retrieving items by path where multiple items share the same name or caption (T1311534). The fix ensures path-based lookups correctly traverse nested groups and return the intended item rather than the first matching name.

Key changes:

• Fixed the _getFieldParts method to correctly reverse the path array after splitting
• Added validation in _getItemByFieldPath to ensure the path node matches before retrieving nested items
• Changed return types from false to null for consistency with TypeScript conventions

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/devextreme/testing/tests/DevExpress.ui.widgets.form/form.tests.js	Added test case verifying itemOption retrieves correct items by path when duplicates exist
packages/devextreme/js/__internal/ui/form/form.utils.ts	Changed return type from false to null for consistency
packages/devextreme/js/__internal/ui/form/form.ts	Fixed path parsing logic and added path validation to prevent incorrect item matching

[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

[Copilot]

The _getFieldParts method incorrectly reverses the fieldPath. When splitting 'a.b.c', it becomes ['c', 'b', 'a'], then destructuring gives fieldName='c' and fieldPath=['b', 'a']. However, the return statement doesn't reverse fieldPath back, so it's returned as ['b', 'a'] instead of ['a', 'b']. The old implementation at line 1498 explicitly reversed the path with resultPath.reverse(). This bug will cause path traversal to fail when looking up nested items.

Suggested change

	fieldPath,
	fieldPath: fieldPath.reverse(),

[Copilot]

The test removed the editorLabelMode parameter when determining resultLabelMode (line 224). The original code at line 1551 in form.tests.js used editorLabelMode || formLabelMode, but the new code only uses formLabelMode. This changes the test logic and may cause incorrect assertions when editorLabelMode is specified but different from formLabelMode.

Suggested change

	const resultLabelMode = formLabelMode;
	const editorLabelMode = $form.dxForm('option', 'items')[0].label?.labelMode;
	const resultLabelMode = editorLabelMode || formLabelMode;