DataGrid - AI Assistant: Remove the onChatCleared callback

[Alyar666]

No description provided.

[Copilot]

Pull request overview

This PR updates the DataGrid AI Assistant chat integration by removing the onChatCleared option/callback and shifting “clear chat” behavior into the AIChat component itself, while also improving regenerate flow by passing the originating AI message back to the controller so it can re-run the original prompt and reset the message state.

Changes:

• Removed onChatCleared from AIChatOptions and made the clear button always present; clicking it now calls AIChat.clear().
• Introduced AIMessage and isAIMessage type guard to consistently identify assistant messages and to pass the AI message into the regenerate callback.
• Updated controller/view logic and tests so regeneration resets an existing message to pending and resends the stored prompt.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/devextreme/js/__internal/grids/grid_core/ai_chat/utils.ts	Removes isAIChatMessage, loosens helpers to accept undefined inputs, and keeps message-state utilities.
packages/devextreme/js/__internal/grids/grid_core/ai_chat/types.ts	Removes onChatCleared, changes onRegenerate signature to receive an AIMessage.
packages/devextreme/js/__internal/grids/grid_core/ai_chat/ai_chat.ts	Clear button now always clears internally; regenerate now passes the message; uses isAIMessage guard.
packages/devextreme/js/__internal/grids/grid_core/ai_chat/ai_chat.test.ts	Updates clear-button expectations and adds a click test validating clear() behavior.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/utils.ts	Adds isAIMessage type guard based on assistant author id.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/types.ts	Introduces AIMessage type to model assistant messages (status/header/prompt/etc.).
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/ai_assistant_view.ts	Routes regeneration through a shared executeRequest helper; removes onChatCleared wiring.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/ai_assistant_controller.ts	Refactors pending message creation to return AIMessage, supports regenerate by resetting an existing message to pending and resending its prompt.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/tests/utils.test.ts	Adds unit tests for the new isAIMessage helper.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/tests/ai_assistant_view.test.ts	Updates view tests to reflect new regenerate flow and removal of isProcessing/onChatCleared.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/tests/ai_assistant_view_controller.integration.test.ts	Adds integration coverage ensuring regenerate resets status to pending and completes successfully.
packages/devextreme/js/__internal/grids/grid_core/ai_assistant/tests/ai_assistant_controller.test.ts	Adds controller coverage for “ignore concurrent request” and for regenerate behavior via AIMessage.