refactor(tool): add Toolkit deep copy to isolate agent state

[AlbumenJ]

No description provided.

[Copilot]

Pull request overview

This PR adds deep copy functionality to the Toolkit class to enable agent state isolation. Each agent built from a ReActAgent.Builder now receives its own deep copy of the toolkit, preventing state interference when multiple agents share the same toolkit configuration.

• Deep copy implementation for Toolkit, ToolRegistry, and ToolGroupManager
• ReActAgent builder now creates toolkit copies per agent instance
• Builder collections changed to Sets (hooks, knowledgeBases) for deduplication
• Integration of ActingChunkEvent notification for streaming tool execution

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
Toolkit.java	Adds copy() method to create deep copies of toolkit instances for agent isolation
ToolRegistry.java	Implements copyTo() to transfer tool registrations between registries
ToolGroupManager.java	Implements copyTo() to duplicate tool group state and active group tracking
ReActAgent.java	Builder creates toolkit deep copy per agent; adds chunk callback for streaming; changes hooks/knowledgeBases to Sets

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[Copilot]

The copyTo method performs a shallow copy by sharing the same AgentTool and RegisteredToolFunction instances between the source and target registries. This violates the deep copy intention stated in the PR.

RegisteredToolFunction has mutable state (the presetParameters field can be modified via updatePresetParameters method). When agents share the same RegisteredToolFunction instance, calling toolkit.updateToolPresetParameters on one agent's toolkit will affect other agents that share the same tool reference.

To properly isolate agent state, each RegisteredToolFunction should be deep copied with its own presetParameters map. Consider creating a copy constructor or copy method in RegisteredToolFunction that creates a new instance with copied state.

Suggested change

	target.registerTool(toolName, tool, registered);
	RegisteredToolFunction registeredCopy = registered == null ? null : registered.copy();
	target.registerTool(toolName, tool, registeredCopy);

[Copilot]

The new copy() method lacks test coverage. Given the critical nature of this functionality for agent state isolation and the comprehensive test suite for Toolkit (ToolkitTest.java has 740 lines of tests), this method should have corresponding tests.

Suggested test scenarios:

1. Verify that modifying copied toolkit's tool groups doesn't affect the original
2. Verify that updating preset parameters in one toolkit doesn't affect the copy
3. Verify that all tools are copied correctly
4. Verify that active groups state is properly isolated
5. Verify that the config is shared (not copied) as intended

[Copilot]

The chunk callback uses .subscribe() which creates a fire-and-forget subscription. This means:

1. Any errors in notifyActingChunk will be silently swallowed
2. The subscription is not managed or cancelled, potentially leading to resource leaks
3. There's no backpressure handling

Consider returning the Mono without subscribing and let the caller manage the subscription, or use .subscribeOn() with proper error handling. Alternatively, if fire-and-forget is intentional, add explicit error handling with .doOnError().

Suggested change

	toolkit.setChunkCallback((toolUse, chunk) -> notifyActingChunk(toolUse, chunk).subscribe());
	toolkit.setChunkCallback(
	(toolUse, chunk) ->
	notifyActingChunk(toolUse, chunk)
	.doOnError(
	error ->
	LoggerFactory.getLogger(ReActAgent.class)
	.error(
	"Error while notifying acting chunk",
	error))
	.subscribe());

[codecov]

Codecov Report

❌ Patch coverage is 54.76190% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...java/io/agentscope/core/tool/ToolGroupManager.java	15.38%	10 Missing and 1 partial ⚠️
...e/src/main/java/io/agentscope/core/ReActAgent.java	55.55%	8 Missing ⚠️

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