refactor fetch-pollyfill (#13)

This pull request includes updates to imports and types from `chatgpt`
and `options.js`, removes import of `node-fetch`, and sets global
variables for `fetch`, `Headers`, `Request`, and `Response`. No new
features were added, but these changes improve the organization and
maintainability of the code.

src/bot.ts

@@ -1,7 +1,7 @@
-import "./fetch-polyfill.js";
-import { Options } from "./options.js";
 import * as core from "@actions/core";
-import { ChatGPTAPI, ChatMessage, SendMessageOptions } from "chatgpt";
+import * as chatgpt from "chatgpt";
+import "./fetch-polyfill.js";
+import * as optionsJs from "./options.js";
 
 // define type to save parentMessageId and conversationId
 export type Ids = {
@@ -10,14 +10,14 @@ export type Ids = {
 };
 
 export class Bot {
- private turbo: ChatGPTAPI | null = null; // not free
+ private turbo: chatgpt.ChatGPTAPI | null = null; // not free
 
- private options: Options;
+ private options: optionsJs.Options;
 
- constructor(options: Options) {
+ constructor(options: optionsJs.Options) {
  this.options = options;
  if (process.env.OPENAI_API_KEY) {
- this.turbo = new ChatGPTAPI({
+ this.turbo = new chatgpt.ChatGPTAPI({
  systemMessage: options.system_message,
  apiKey: process.env.OPENAI_API_KEY,
  debug: options.debug,
@@ -54,9 +54,9 @@ export class Bot {
  core.info(`sending to chatgpt: ${message}`);
  }
 
- let response: ChatMessage | null = null;
+ let response: chatgpt.ChatMessage | null = null;
  if (this.turbo) {
- let opts: SendMessageOptions = {};
+ let opts: chatgpt.SendMessageOptions = {};
  if (ids.parentMessageId) {
  opts.parentMessageId = ids.parentMessageId;
  }

src/fetch-polyfill.ts

@@ -0,0 +1,8 @@
+import fetch, * as nodeFetch from "node-fetch";
+
+if (!globalThis.fetch) {
+ globalThis.fetch = fetch;
+ globalThis.Headers = nodeFetch.Headers;
+ globalThis.Request = nodeFetch.Request;
+ globalThis.Response = nodeFetch.Response;
+}