export function aggregateResponses()

in src/requests/stream-reader.ts [153:225]
67 lines of code
17 McCabe index (conditional complexity)

export function aggregateResponses(
  responses: GenerateContentResponse[],
): GenerateContentResponse {
  const lastResponse = responses[responses.length - 1];
  const aggregatedResponse: GenerateContentResponse = {
    promptFeedback: lastResponse?.promptFeedback,
  };
  for (const response of responses) {
    if (response.candidates) {
      let candidateIndex = 0;
      for (const candidate of response.candidates) {
        if (!aggregatedResponse.candidates) {
          aggregatedResponse.candidates = [];
        }
        if (!aggregatedResponse.candidates[candidateIndex]) {
          aggregatedResponse.candidates[candidateIndex] = {
            index: candidateIndex,
          } as GenerateContentCandidate;
        }
        // Keep overwriting, the last one will be final
        aggregatedResponse.candidates[candidateIndex].citationMetadata =
          candidate.citationMetadata;
        aggregatedResponse.candidates[candidateIndex].groundingMetadata =
          candidate.groundingMetadata;
        aggregatedResponse.candidates[candidateIndex].finishReason =
          candidate.finishReason;
        aggregatedResponse.candidates[candidateIndex].finishMessage =
          candidate.finishMessage;
        aggregatedResponse.candidates[candidateIndex].safetyRatings =
          candidate.safetyRatings;

        /**
         * Candidates should always have content and parts, but this handles
         * possible malformed responses.
         */
        if (candidate.content && candidate.content.parts) {
          if (!aggregatedResponse.candidates[candidateIndex].content) {
            aggregatedResponse.candidates[candidateIndex].content = {
              role: candidate.content.role || "user",
              parts: [],
            };
          }
          const newPart: Partial<Part> = {};
          for (const part of candidate.content.parts) {
            if (part.text) {
              newPart.text = part.text;
            }
            if (part.functionCall) {
              newPart.functionCall = part.functionCall;
            }
            if (part.executableCode) {
              newPart.executableCode = part.executableCode;
            }
            if (part.codeExecutionResult) {
              newPart.codeExecutionResult = part.codeExecutionResult;
            }
            if (Object.keys(newPart).length === 0) {
              newPart.text = "";
            }
            aggregatedResponse.candidates[candidateIndex].content.parts.push(
              newPart as Part,
            );
          }
        }
      }
      candidateIndex++;
    }
    if (response.usageMetadata) {
      aggregatedResponse.usageMetadata = response.usageMetadata;
    }
  }
  return aggregatedResponse;
}