[oyi77]

Part of modularization effort (Issue #3594).

Extracts SSE formatting utilities from the monolithic open-sse/utils/stream.ts into a dedicated module.

Changes:

• New file: open-sse/utils/stream/sseFormatters.ts (89 lines)
• Exports: buildResponsesFunctionCallEvents, formatSSEDataEvents, toChatCompletionChunkWithToolCall, toResponsesCompletedWithToolCalls

Testing: No behavior change. Existing stream tests pass.

Follow-up PRs will extract: types (#3917), utils (#3918), errors (#3919), textualToolCalls (#3920), openaiChunks, claudeLifecycle, responsesLifecycle, and streamCore.

[gemini-code-assist]

Code Review

This pull request introduces a new utility file open-sse/utils/stream/sseFormatters.ts containing helper functions for formatting SSE data events and transforming tool calls. The review feedback correctly identifies unused imports (convertOpenAIToResponsesToolCall and uuidv4) at the top of the file that should be removed to maintain clean code.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[gemini-code-assist]

The imports convertOpenAIToResponsesToolCall and uuidv4 are unused in this file and should be removed to keep the imports clean.

Suggested change

	import { convertOpenAIToResponsesToolCall } from "../handlers/responseTranslator.ts";
	import { v4 as uuidv4 } from "uuid";
	import { asRecord } from "./utils.ts";
	import { JsonRecord, ToolCall } from "./types.ts";
	import { asRecord } from "./utils.ts";
	import { JsonRecord, ToolCall } from "./types.ts";

[diegosouzapw]

Thanks, @oyi77 🙏. These stream extractions are currently additive — the new modules under open-sse/utils/stream/ aren't wired into stream.ts yet, so they don't change runtime behavior on their own. Rather than land the decomposition in fragments, we're going to fold the stream split into the single coordinated modularization pass (Issue #3594) after the quality-gate work lands, so the extraction and the rewiring get sequenced together and verified lossless in one go. Closing for now — purely sequencing, not a reflection on the work; input welcome on #3594 once the plan is up.