protected async _runTools()

in src/lib/AbstractChatCompletionRunner.ts [354:481]
111 lines of code
25 McCabe index (conditional complexity)

  protected async _runTools<FunctionsArgs extends BaseFunctionsArgs>(
    client: OpenAI,
    params:
      | ChatCompletionToolRunnerParams<FunctionsArgs>
      | ChatCompletionStreamingToolRunnerParams<FunctionsArgs>,
    options?: RunnerOptions,
  ) {
    const role = 'tool' as const;
    const { tool_choice = 'auto', stream, ...restParams } = params;
    const singleFunctionToCall = typeof tool_choice !== 'string' && tool_choice?.function?.name;
    const { maxChatCompletions = DEFAULT_MAX_CHAT_COMPLETIONS } = options || {};

    // TODO(someday): clean this logic up
    const inputTools = params.tools.map((tool): RunnableToolFunction<any> => {
      if (isAutoParsableTool(tool)) {
        if (!tool.$callback) {
          throw new OpenAIError('Tool given to `.runTools()` that does not have an associated function');
        }

        return {
          type: 'function',
          function: {
            function: tool.$callback,
            name: tool.function.name,
            description: tool.function.description || '',
            parameters: tool.function.parameters as any,
            parse: tool.$parseRaw,
            strict: true,
          },
        };
      }

      return tool as any as RunnableToolFunction<any>;
    });

    const functionsByName: Record<string, RunnableFunction<any>> = {};
    for (const f of inputTools) {
      if (f.type === 'function') {
        functionsByName[f.function.name || f.function.function.name] = f.function;
      }
    }

    const tools: ChatCompletionTool[] =
      'tools' in params ?
        inputTools.map((t) =>
          t.type === 'function' ?
            {
              type: 'function',
              function: {
                name: t.function.name || t.function.function.name,
                parameters: t.function.parameters as Record<string, unknown>,
                description: t.function.description,
                strict: t.function.strict,
              },
            }
          : (t as unknown as ChatCompletionTool),
        )
      : (undefined as any);

    for (const message of params.messages) {
      this._addMessage(message, false);
    }

    for (let i = 0; i < maxChatCompletions; ++i) {
      const chatCompletion: ChatCompletion = await this._createChatCompletion(
        client,
        {
          ...restParams,
          tool_choice,
          tools,
          messages: [...this.messages],
        },
        options,
      );
      const message = chatCompletion.choices[0]?.message;
      if (!message) {
        throw new OpenAIError(`missing message in ChatCompletion response`);
      }
      if (!message.tool_calls?.length) {
        return;
      }

      for (const tool_call of message.tool_calls) {
        if (tool_call.type !== 'function') continue;
        const tool_call_id = tool_call.id;
        const { name, arguments: args } = tool_call.function;
        const fn = functionsByName[name];

        if (!fn) {
          const content = `Invalid tool_call: ${JSON.stringify(name)}. Available options are: ${Object.keys(
            functionsByName,
          )
            .map((name) => JSON.stringify(name))
            .join(', ')}. Please try again`;

          this._addMessage({ role, tool_call_id, content });
          continue;
        } else if (singleFunctionToCall && singleFunctionToCall !== name) {
          const content = `Invalid tool_call: ${JSON.stringify(name)}. ${JSON.stringify(
            singleFunctionToCall,
          )} requested. Please try again`;

          this._addMessage({ role, tool_call_id, content });
          continue;
        }

        let parsed;
        try {
          parsed = isRunnableFunctionWithParse(fn) ? await fn.parse(args) : args;
        } catch (error) {
          const content = error instanceof Error ? error.message : String(error);
          this._addMessage({ role, tool_call_id, content });
          continue;
        }

        // @ts-expect-error it can't rule out `never` type.
        const rawContent = await fn.function(parsed, this);
        const content = this.#stringifyFunctionCallResult(rawContent);
        this._addMessage({ role, tool_call_id, content });

        if (singleFunctionToCall) {
          return;
        }
      }
    }

    return;
  }