fix(agent-runtime): preserve non-text content blocks in MessageConverter

[jerryliang64]

Summary

• 修复 MessageConverter.toContentBlocks() 有损转换问题：原实现通过 .filter(part => part.type === 'text') 过滤掉了所有非 text 类型的 content block（如 tool_use、tool_result），导致基于 @anthropic-ai/claude-agent-sdk 实现 execRun 时，工具调用信息在转换后丢失
• 修复 MessageConverter.toInputMessageObjects() 同样的有损问题：原实现将所有 content part 当作 text 处理，非 text 块的 .text 为 undefined
• 扩展类型系统：在 ContentBlockType 中新增 ToolUse、ToolResult，新增对应的输入/输出类型接口，并增加 GenericContentBlock 兜底未来新类型
• 提供 type guard 函数：isTextBlock()、isToolUseBlock()、isToolResultBlock() 方便业务代码做类型收窄

Affected areas

影响面	修复前	修复后
Thread 历史消息	tool_use 块被丢弃	完整保留
SSE 流式 delta	不包含 tool_use 事件	包含所有 content block
Run output	缺少 tool_use block	完整保留

Test plan

• toContentBlocks 保留 tool_use content parts
• toContentBlocks 保留 tool_result content parts（含 is_error 标记）
• toContentBlocks 保留未知类型 content parts（generic 兜底）
• toContentBlocks 保持混合类型的顺序
• toMessageObject 保留 tool_use blocks
• extractFromStreamMessages 正确提取包含 tool_use 的消息
• toInputMessageObjects 保留 tool_use / tool_result blocks
• type guard 函数正确收窄类型
• 所有 116 个测试通过

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Added support for tool use and tool result content blocks in message handling.
  • Message conversion now preserves all content block types instead of filtering non-text content.

• Improvements

  • Enhanced type safety with expanded content block type definitions.
  • Improved message processing to handle mixed content ordering across text, tool use, and tool result blocks.

[coderabbitai]

📝 Walkthrough

Walkthrough

The changes expand message content handling to support tool-related blocks (tool_use, tool_result, generic) alongside text blocks. Type guards are added to discriminate content variants. Conversion logic in MessageConverter is updated to preserve non-text blocks instead of filtering them, and new content-part interfaces are introduced for input/output typing.

Changes

Cohort / File(s)	Summary
Message Conversion Logic core/agent-runtime/src/MessageConverter.ts	Added type-guard functions (isTextBlock, isToolUseBlock, isToolResultBlock) to discriminate MessageContentBlock variants. Updated toContentBlocks and toInputMessageObjects to preserve and pass through non-text content blocks instead of filtering them out.
Type Definitions core/types/agent-runtime/AgentMessage.ts	Expanded ContentBlockType to include ToolUse and ToolResult. Introduced distinct content-part interfaces for input (TextInputContentPart, ToolUseInputContentPart, ToolResultInputContentPart, GenericInputContentPart) and output (ToolUseContentBlock, ToolResultContentBlock, GenericContentBlock). Updated InputContentPart and MessageContentBlock to unions of their variants. Updated InputMessage.content type to reflect new structure.
Type Exports core/tegg/agent.ts	Added re-exports of new content-part and content-block types, plus type-guard functions (isTextBlock, isToolUseBlock, isToolResultBlock) from agent-runtime.
Test Coverage core/agent-runtime/test/MessageConverter.test.ts	Extended assertions to validate type-guard narrowing. Added tests for preservation of tool_use, tool_result, and generic blocks through conversion methods. Added dedicated type-guard validation tests.
Runtime Tests core/agent-runtime/test/AgentRuntime.test.ts	Updated completion test assertions to validate first content block is text before accessing text.value property.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐰 We've woven new threads through the types today,
Tool blocks now dance in the content's ballet,
Guards keep things safe, type-checked all the way,
From text to tools—no more sorting fray,
The message now flows like clover at play! 🍀

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding preservation of non-text content blocks in MessageConverter, which is the core fix addressed across all modified files.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch worktree-fix-lossy-content-blocks

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[gemini-code-assist]

Code Review

This pull request introduces support for tool-related content blocks (tool_use, tool_result) and generic blocks within the agent runtime. It includes new type definitions, type guards, and updates to the MessageConverter to ensure these blocks are preserved during message processing. Comprehensive tests have been added to verify the handling of mixed content types. A review comment identifies an opportunity to reduce code duplication in MessageConverter.ts by reusing the toContentBlocks method.

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@core/types/agent-runtime/AgentMessage.ts`:
- Around line 76-78: The InputMessage.content type change breaks existing
callers and the MessageConverter which assumes non-string content is an array;
update the InputMessage interface to accept string | InputContentPart |
InputContentPart[] (restore single-object support) and then normalize inside the
MessageConverter method that maps content (the mapping call around
MessageConverter.ts:148) by treating a single InputContentPart as [part] before
calling .map(); ensure the converter branches handle string, single object, and
array uniformly so tests and examples continue to work.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: d8cfd482-70d7-4340-b704-3b69475a85d9

📥 Commits

Reviewing files that changed from the base of the PR and between 0c77cd1 and 5b93066.

📒 Files selected for processing (5)

• core/agent-runtime/src/MessageConverter.ts
• core/agent-runtime/test/AgentRuntime.test.ts
• core/agent-runtime/test/MessageConverter.test.ts
• core/tegg/agent.ts
• core/types/agent-runtime/AgentMessage.ts