Consolidate MockChatService

[mjbvz]

We have two MockChatService classes. This makes updating the interface slow since you have to update both locations. The two also behave slightly differently. After a quick code review I think they can be consolidated

[Copilot]

Pull request overview

This PR consolidates duplicated MockChatService implementations used in chat-related tests, aiming to reduce maintenance burden and keep test behavior consistent with the IChatService interface.

Changes:

• Updated the shared MockChatService implementation to cover the behavior previously embedded in a browser test.
• Removed the inline MockChatService from localAgentSessionsController.test.ts and switched the test to import the shared mock.
• Adjusted test calls to match the shared mock’s API (e.g., addSession(mockModel)).

Reviewed changes

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

File	Description
src/vs/workbench/contrib/chat/test/common/chatService/mockChatService.ts	Refactors the shared mock service implementation to support more test scenarios and centralize behavior.
src/vs/workbench/contrib/chat/test/browser/agentSessions/localAgentSessionsController.test.ts	Removes the local mock and consumes the shared mock service instead.

Comments suppressed due to low confidence (3)

src/vs/workbench/contrib/chat/test/common/chatService/mockChatService.ts:136

• IChatService.addCompleteRequest is defined with five parameters (sessionResource/message/variableData/attempt/response). The mock currently declares addCompleteRequest() with no parameters, which removes compile-time pressure to keep the mock aligned with the interface. Please update the method signature to match IChatService.addCompleteRequest (unused params can be _-prefixed).

	addCompleteRequest(): void { }

src/vs/workbench/contrib/chat/test/common/chatService/mockChatService.ts:152

• notifyQuestionCarouselAnswer should use the service’s IChatQuestionAnswers | undefined type for its answers parameter (per IChatService) rather than Record<string, unknown>. Using the real type keeps this mock in sync with interface changes and prevents accidentally accepting/producing shapes that production code can’t handle.

	notifyQuestionCarouselAnswer(_requestId: string, _resolveId: string, _answers: Record<string, unknown> | undefined): void { }

src/vs/workbench/contrib/chat/test/common/chatService/mockChatService.ts:156

• IChatService.transferChatSession and IChatService.setChatSessionTitle both take (sessionResource: URI, ...) parameters. In this mock they are currently declared with no parameters, which again weakens compile-time alignment with the interface and can hide breaking signature changes. Please update both method signatures to match IChatService (parameters can be unused).

	async transferChatSession(): Promise<void> { }

	setChatSessionTitle(): void { }