[BUG] Repeated Gemini generate context stream errors

[nilbounce1]

Problem (one or two sentences)

Gemini generate context stream error: {"error":{"message":"{\n  "error": {\n    "code": 400,\n    "message": "* GenerateContentRequest.contents[4].parts[2].data: required oneof field 'data' must have one initialized field\n",\n    "status": "INVALID_ARGUMENT"\n  }\n}\n","code":400,"status":"Bad Request"}}

Retry attempt 1
Retrying now...


Gemini generate context stream error: {"error":{"message":"{\n  "error": {\n    "code": 400,\n    "message": "* GenerateContentRequest.contents[4].parts[2].data: required oneof field 'data' must have one initialized field\n",\n    "status": "INVALID_ARGUMENT"\n  }\n}\n","code":400,"status":"Bad Request"}}

Retry attempt 2
Retrying now...


Gemini generate context stream error: {"error":{"message":"{\n  "error": {\n    "code": 400,\n    "message": "* GenerateContentRequest.contents[4].parts[2].data: required oneof field 'data' must have one initialized field\n",\n    "status": "INVALID_ARGUMENT"\n  }\n}\n","code":400,"status":"Bad Request"}}

Context (who is affected and when)

On new_task delegation

Reproduction steps

Ubuntu 24

Expected result

The task should progress

Actual result

Error

Variations tried (optional)

No response

App Version

Version: 3.35.5 (6aedc05)

API Provider (optional)

Google Gemini

Model Used (optional)

Gemini Flash Latest

Roo Code Task Links (optional)

No response

Relevant logs or errors (optional)

[roomote]

I've analyzed this issue and here's my proposed implementation plan:

Root Cause

The error "GenerateContentRequest.contents[4].parts[2].data: required oneof field 'data' must have one initialized field" indicates that the Gemini API is receiving a malformed request where one of the content parts has an empty or uninitialized data field.

Analysis

After examining the codebase, I found that in src/api/transform/gemini-format.ts, the convertAnthropicContentToGemini function can return empty arrays in several cases:

• When a thoughtSignature block is encountered but shouldn't be included (line 60)
• When a tool_result has no content (line 84)
• When a tool_result has non-array/non-string content (line 106)
• When unsupported content block types are encountered (line 135)

These empty arrays are then included in the parts array, and when convertAnthropicMessageToGemini creates a Content object with these parts, it can result in messages with empty parts arrays being sent to Gemini.

Proposed Solution

1. Filter out empty parts: Modify convertAnthropicMessageToGemini to filter out any empty parts before creating Content objects
2. Skip messages with no valid parts: Don't create Content objects for messages that have no valid parts after filtering
3. Add validation: Ensure that the final contents array sent to Gemini API doesn't contain any empty or malformed entries

This approach will prevent the API from receiving requests with empty data fields while maintaining backward compatibility.

Please mention @roomote in a comment saying that you approve this plan, and I'll proceed with the implementation.

[nilbounce1]

@roomote

[roomote]

I see your comment and will proceed with implementing the fix for the Gemini API error. I'll open a PR to share progress on addressing the empty data field issue in the Gemini format conversion.

[roomote]

Opened PR #9824 with my attempt at addressing this issue.

The fix filters out empty parts that were being sent to the Gemini API, which was causing the "required oneof field data must have one initialized field" error. I've added comprehensive test coverage for the edge cases.

Feedback welcome!