fix(core): propagate acting middleware result rewrites

[dangzitou]

AgentScope-Java Version

2.0.3-SNAPSHOT

Description

Fixes #2672.

ReActAgent.actingStream published raw tool-result events before the onActing middleware chain. The acting phase then discarded the post-middleware events and continued with the raw resultHolder, so a middleware rewrite was visible neither to event consumers nor to the next model call.

This change:

• publishes acting events after the middleware chain;
• detects tool-result delta/end events that middleware replaced or filtered;
• rebuilds only the affected ToolResultBlock values from the transformed stream;
• preserves the original result object when middleware passes all result events through unchanged.

The new end-to-end regression test rewrites search:alpha to rewritten. On current main it failed because the public stream returned search:alpha; with this change both the public stream and the second model request contain only rewritten.

Tests

• mvn -pl agentscope-core -Dtest=ReActAgentNewLoopE2ETest#actingMiddlewareCanRewriteToolResultForEventsAndNextModelCall test — 1 passed
• mvn -pl agentscope-core -Dtest=ReActAgentNewLoopE2ETest,ReActAgentMiddlewareIntegrationTest test — 12 passed
• mvn -pl agentscope-core test — 2275 passed, 9 skipped
• Spotless check passed as part of the Maven builds

Compatibility and risk

No public API signatures change. Existing tool results retain their original ToolResultBlock instance unless middleware actually changes the tool-result event sequence. Text and data deltas, metadata, and end state are retained when rebuilding a transformed result.

Checklist

• Code has been formatted with mvn spotless:apply
• All relevant tests are passing
• Javadoc comments are complete and follow project conventions
• Related middleware documentation has been updated
• Code is ready for review

[codecov]

Codecov Report

❌ Patch coverage is 73.61111% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...e/src/main/java/io/agentscope/core/ReActAgent.java	73.61%	8 Missing and 11 partials ⚠️

📢 Thoughts on this report? Let us know!

[Copilot]

Pull request overview

This PR fixes ReActAgent acting-phase middleware rewrites so that transformed tool-result events are what downstream consumers observe and what the next model iteration receives, addressing issue #2672.

Changes:

• Publish acting-phase tool-result events after the onActing middleware chain, not before it.
• Detect when middleware replaces/filters tool-result delta/end events and rebuild only the affected ToolResultBlock values (preserving original instances when unchanged).
• Add an end-to-end regression test ensuring a middleware rewrite is reflected both in the public event stream and the subsequent model request.

Reviewed changes

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

File	Description
agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java	Moves event publication post-middleware and reconstructs tool results from the transformed event stream when needed.
agentscope-core/src/main/java/io/agentscope/core/middleware/MiddlewareBase.java	Documents that tool-result delta-event transformations affect the next-iteration result message.
agentscope-core/src/test/java/io/agentscope/core/agent/ReActAgentNewLoopE2ETest.java	Adds an E2E regression test covering acting middleware rewriting tool results for events and next model call.

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