fix(xai): map server-side tool types to toolName when part.name is empty

[archodev]

Problem

When using xai.tools.webSearch() with xai.responses() and streamText, tool-call events are emitted with empty toolName, causing AI_NoSuchToolError.

Example of the error:

{
  "type": "tool-call",
  "toolCallId": "ws_24e5ff31-0c00-48c9-c980-671b70dd254e_call_48407951",
  "toolName": "",
  "invalid": true,
  "error": {
    "name": "AI_NoSuchToolError",
    "toolName": "",
    "availableTools": ["web_search"]
  }
}

Root Cause

In xai-responses-language-model.ts, the code maps part.name to the user's tool name, but only checks if part.name matches specific sub-tool names like web_search, browse_page, etc.

When xAI returns web_search_call events, part.name may be undefined or empty, so the mapping fails and toolName remains an empty string.

Solution

Check part.type in addition to part.name to correctly identify server-side tools:

• web_search_call → webSearchToolName
• x_search_call → xSearchToolName
• code_execution_call / code_interpreter_call → codeExecutionToolName
• view_image_call → view_image
• view_x_video_call → view_x_video

Changes

• Fixed tool name mapping in both doGenerate and doStream methods
• Added 5 test cases to verify correct mapping when part.name is empty

Testing

• All 120 existing tests pass
• Added new tests for empty part.name scenarios
• Verified fix with real xAI API calls using streamText with xai.tools.webSearch()

Fixes #11263

[aayush-kapoor]

hi marking this as closed since this has been fixed via #11530