for await()

in packages/instrumentation-openai/src/instrumentation.ts [399:469]
65 lines of code
15 McCabe index (conditional complexity)

    for await (const chunk of streamIter as any) {
      yield chunk;

      // Gather telemetry from this chunk.
      debug('OpenAI.Chat.Completions.create stream chunk: %O', chunk);
      if (config.captureMessageContent) {
        const contentPart = chunk.choices[0]?.delta?.content;
        if (contentPart) {
          contentParts.push(contentPart);
        }
      }
      // Assume delta.tool_calls, if exists, is an array of length 1.
      const toolCallPart = chunk.choices[0]?.delta?.tool_calls?.[0];
      if (toolCallPart) {
        if (toolCallPart.id) {
          // First chunk in a tool call.
          toolCalls.push({
            id: toolCallPart.id,
            type: toolCallPart.type,
            function: {
              name: toolCallPart.function?.name,
              arguments: toolCallPart.function?.arguments ?? '',
            },
          });
        } else if (toolCalls.length > 0) {
          // A tool call chunk with more of the `function.arguments`.
          toolCalls[toolCalls.length - 1].function.arguments +=
            toolCallPart.function?.arguments ?? '';
        }
      }
      if (!id && chunk.id) {
        id = chunk.id;
        span.setAttribute(ATTR_GEN_AI_RESPONSE_ID, id);
      }
      if (!model && chunk.model) {
        model = chunk.model;
        span.setAttribute(ATTR_GEN_AI_RESPONSE_MODEL, model);
      }
      if (!role) {
        role = chunk.choices[0]?.delta?.role;
      }
      if (!finishReason) {
        finishReason = chunk.choices[0]?.finish_reason;
        if (finishReason) {
          span.setAttribute(ATTR_GEN_AI_RESPONSE_FINISH_REASONS, [
            finishReason,
          ]);
        }
      }
      if (chunk.usage) {
        // A final usage chunk if `stream_options.include_usage: true`.
        span.setAttribute(
          ATTR_GEN_AI_USAGE_INPUT_TOKENS,
          chunk.usage.prompt_tokens
        );
        span.setAttribute(
          ATTR_GEN_AI_USAGE_OUTPUT_TOKENS,
          chunk.usage.completion_tokens
        );
        this._genaiClientTokenUsage.record(chunk.usage.prompt_tokens, {
          ...commonAttrs,
          [ATTR_GEN_AI_RESPONSE_MODEL]: model,
          [ATTR_GEN_AI_TOKEN_TYPE]: 'input',
        });
        this._genaiClientTokenUsage.record(chunk.usage.completion_tokens, {
          ...commonAttrs,
          [ATTR_GEN_AI_RESPONSE_MODEL]: model,
          [ATTR_GEN_AI_TOKEN_TYPE]: 'output',
        });
      }
    }