Convert backend to Typescript

* 59 move to typescript - backend

note: tests have not been migrated yet

* WIP: First TS backend pass

* nodemon backend

* Typing for function call

* Readded defence configuration values

* Using model enum

* Fixed defences

* Removed unused variables

* Get rid of some anys

* Blocked message reason

* Moved LLM evaluation check

* Better chat types

* Including test files in tsconfig

* Renamed test js files to ts

* WIP: Fixing tests

* Defence unit test

* Email defence unit test

* All unit tests passing

* Removed session from method

* Removed session from openai methods

* OpenAI ts integration tests

* Removed document integration test as it needs redoing

* Removed unused export

* Backend phase enum

* Removed empty settings file

* Removed unused dep

* Consistent function naming

* Fixed test

* Removed unecessary frontend key

* Using phase enum in the frontend

* Using easy QA prompt by default

---------

Co-authored-by: Scott Rowan <srowan@scottlogic.com>

.gitignore

@@ -40,7 +40,7 @@ bower_components
 .lock-wscript
 
 # Compiled binary addons (https://nodejs.org/api/addons.html)
-build/Release
+build/
 
 # Dependency directories
 node_modules/

backend/jest.config.js

@@ -0,0 +1,5 @@
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+};

backend/package.json

@@ -11,11 +11,18 @@
     "react": "^18.2.0"
   },
   "devDependencies": {
-    "jest": "^29.6.1"
+    "@types/cors": "^2.8.13",
+    "@types/express": "^4.17.17",
+    "@types/express-session": "^1.17.7",
+    "@types/jest": "^29.5.3",
+    "@types/node": "^20.4.5",
+    "nodemon": "^3.0.1",
+    "ts-jest": "^29.1.1",
+    "ts-node": "^10.9.1",
+    "typescript": "^4.1.6"
   },
   "scripts": {
-    "dev": "node ./src/app.js",
+    "dev": "nodemon -r dotenv/config src/app.ts",
     "test": "jest"
   }
 }
-

backend/src/app.ts

@@ -0,0 +1,100 @@
+import cors from "cors";
+import dotenv from "dotenv";
+import express from "express";
+import session from "express-session";
+
+import { getInitialDefences, getQALLMprePrompt } from "./defence";
+import { setOpenAiApiKey } from "./openai";
+import { router } from "./router";
+import { ChatCompletionRequestMessage } from "openai";
+import { EmailInfo } from "./models/email";
+import { DefenceInfo } from "./models/defence";
+import { CHAT_MODELS } from "./models/chat";
+import { retrievalQAPrePrompt } from "./promptTemplates";
+
+dotenv.config();
+
+declare module "express-session" {
+  interface Session {
+    chatHistory: ChatCompletionRequestMessage[];
+    sentEmails: EmailInfo[];
+    defences: DefenceInfo[];
+    apiKey: string;
+    gptModel: CHAT_MODELS;
+    numPhasesCompleted: number;
+  }
+}
+
+// by default runs on port 3001
+const port = process.env.PORT || String(3001);
+// use default model
+const defaultModel = CHAT_MODELS.GPT_4;
+
+// Creating express server
+const app = express();
+// for parsing application/json
+app.use(express.json());
+
+// use session
+const express_session: session.SessionOptions = {
+  secret: process.env.SESSION_SECRET || "secret",
+  name: "prompt-injection.sid",
+  resave: false,
+  saveUninitialized: true,
+  cookie: {
+    secure: false,
+  },
+};
+
+// serve secure cookies in production
+if (app.get("env") === "production") {
+  if (!express_session.cookie) {
+    express_session.cookie = { secure: true };
+  } else {
+    express_session.cookie.secure = true;
+  }
+}
+app.use(session(express_session));
+
+app.use(
+  cors({
+    credentials: true,
+    origin: true,
+  })
+);
+
+app.use((req, _res, next) => {
+  // initialise session variables
+  if (!req.session.chatHistory) {
+    req.session.chatHistory = [];
+  }
+  if (!req.session.sentEmails) {
+    req.session.sentEmails = [];
+  }
+  if (!req.session.defences) {
+    req.session.defences = getInitialDefences();
+  }
+  if (!req.session.apiKey) {
+    req.session.apiKey = process.env.OPENAI_API_KEY || "";
+  }
+  if (!req.session.gptModel) {
+    req.session.gptModel = defaultModel;
+  }
+  if (!req.session.numPhasesCompleted) {
+    req.session.numPhasesCompleted = 0;
+  }
+  next();
+});
+
+app.use("/", router);
+app.listen(port, () => {
+  console.log("Server is running on port: " + port);
+
+  // for dev purposes only - set the API key from the environment variable
+  const envOpenAiKey = process.env.OPENAI_API_KEY;
+  const prePrompt = retrievalQAPrePrompt;
+  if (envOpenAiKey && prePrompt) {
+    console.debug("Initializing models with API key from environment variable");
+    setOpenAiApiKey(envOpenAiKey, defaultModel, prePrompt);
+  }
+});