fix: propagate Reactor context to chunk event hooks in ReActAgent

[Vinke2]

Three bare .subscribe() calls in ReActAgent (fireReasoningChunk, fireActingChunk, fireSummaryChunk) created new subscription chains without the parent Reactor context, causing ReasoningChunkEvent, ActingChunkEvent, and SummaryChunkEvent to have an empty ContextView in downstream hooks.

Fix each with Flux.deferContextual + contextWrite to capture and propagate the parent context, matching the existing pattern used by executeToolCalls at line 2389-2391.

AgentScope-Java Version

[The version of AgentScope-Java you are working on, e.g. 1.0.12, check your pom.xml dependency version or run mvn dependency:tree | grep agentscope-parent:pom(only mac/linux)]

Description

[Please describe the background, purpose, changes made, and how to test this PR]

Checklist

Please check the following items before code is ready to be reviewed.

• Code has been formatted with mvn spotless:apply
• All tests are passing (mvn test)
• Javadoc comments are complete and follow project conventions
• Related documentation has been updated (e.g. links, examples, etc.)
• Code is ready for review

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

❌ Patch coverage is 72.91667% with 13 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...e/src/main/java/io/agentscope/core/ReActAgent.java	72.91%	8 Missing and 5 partials ⚠️

📢 Thoughts on this report? Let us know!

[AgentScopeJavaBot]

🤖 AI Review

This is a well-targeted bug fix that correctly addresses Reactor context loss in three fire-and-forget .subscribe() calls within ReActAgent. The bare .subscribe() calls for fireReasoningChunk, fireActingChunk, and fireSummaryChunk created independent subscription chains that did not inherit the parent Reactor context, causing downstream hooks to see an empty ContextView — notably losing access to the SubagentEventBus. The fix applies Flux.deferContextual + contextWrite to capture and propagate the parent context, matching the existing pattern already established for executeToolCalls in the same file. The approach is correct, consistent, and minimal in scope.

[AgentScopeJavaBot]

[minor] The .subscribe() call remains bare — no error consumer is provided. If a hook's onEvent throws (or the Mono<Void> signals an error), Reactor will invoke onErrorDropped, silently swallowing the exception. This is a pre-existing issue, not introduced by this PR, but since you're already touching this line, consider adding a minimal error handler (e.g. .subscribe(v -> {}, e -> log.warn("Reasoning chunk hook failed", e))) to surface failures. Same applies to lines 2463 and 2975.

[AgentScopeJavaBot]

[nit] Consider adding a brief inline comment explaining why Flux.deferContextual is needed here (e.g. // Propagate parent Reactor context so chunk hooks can access SubagentEventBus), similar to the existing comment at line 2402–2406 for executeToolCalls. This helps future readers understand the non-obvious context-propagation requirement without having to trace the full call chain.

[AgentScopeJavaBot]

🤖 AI Review

This is a well-targeted bug fix that correctly addresses Reactor context loss in three fire-and-forget .subscribe() calls within ReActAgent. The bare .subscribe() calls for fireReasoningChunk, fireActingChunk, and fireSummaryChunk created independent subscription chains that did not inherit the parent Reactor context, causing downstream hooks to see an empty ContextView — notably losing access to the SubagentEventBus. The fix applies Flux.deferContextual + contextWrite to capture and propagate the parent context, matching the existing pattern already established for executeToolCalls in the same file. The approach is correct, consistent, and minimal in scope.

[AgentScopeJavaBot]

[minor] The .subscribe() call remains bare — no error consumer is provided. If a hook's onEvent throws (or the Mono<Void> signals an error), Reactor will invoke onErrorDropped, silently swallowing the exception. This is a pre-existing issue, not introduced by this PR, but since you're already touching this line, consider adding a minimal error handler (e.g. .subscribe(v -> {}, e -> log.warn("Reasoning chunk hook failed", e))) to surface failures. Same applies to lines 2463 and 2975.

[AgentScopeJavaBot]

[nit] Consider adding a brief inline comment explaining why Flux.deferContextual is needed here (e.g. // Propagate parent Reactor context so chunk hooks can access SubagentEventBus), similar to the existing comment at line 2402–2406 for executeToolCalls. This helps future readers understand the non-obvious context-propagation requirement without having to trace the full call chain.