Add schema validation

jest.config.js

@@ -0,0 +1,7 @@
+/** @type {import('ts-jest').JestConfigWithTsJest} **/
+module.exports = {
+  testEnvironment: 'node',
+  transform: {
+    '^.+.tsx?$': ['ts-jest', {}],
+  },
+}

package.json

@@ -1,13 +1,13 @@
 {
   "name": "@lambda-feedback-segp-sandbox/ef-test-server",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "main": "dist/index.js",
   "scripts": {
     "build": "yarn tsc",
     "format": "prettier --write \"**/*.{js,json,ts,tsx}\"",
     "start": "yarn node dist/index.js",
     "test:types": "yarn tsc --noEmit",
-    "test": "yarn test:types"
+    "test": "yarn test:types && yarn jest"
   },
   "bin": "dist/start.js",
   "files": [
@@ -17,14 +17,18 @@
     "axios": "^1.7.9",
     "cors": "^2.8.5",
     "dotenv": "^16.4.7",
-    "express": "^4.21.2"
+    "express": "^4.21.2",
+    "zod": "^3.24.1"
   },
   "devDependencies": {
+    "@jest/globals": "^29.7.0",
     "@types/cors": "^2.8.17",
     "@types/express": "^5.0.0",
     "@types/node": "^22.10.9",
     "eslint": "^9.18.0",
+    "jest": "^29.7.0",
     "prettier": "^3.4.2",
+    "ts-jest": "^29.2.5",
     "typescript": "^5.7.3"
   }
 }

src/handler.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, test } from '@jest/globals'
+
+import { parseRequestBody } from './handler'
+
+describe('parseRequestBody', () => {
+  test('correctly extracts expected fields', () => {
+    expect(
+      parseRequestBody({
+        url: 'url',
+        answer: 'answer',
+        response: 'response',
+        params: { param: 'param' },
+      }),
+    ).toStrictEqual({
+      url: 'url',
+      evaluationFunctionRequestData: {
+        answer: 'answer',
+        response: 'response',
+        params: { param: 'param' },
+      },
+    })
+  })
+
+  test('rejects requests with missing fields', () => {
+    expect(
+      parseRequestBody({
+        answer: 'answer',
+        response: 'response',
+        params: { param: 'param' },
+      }),
+    ).toBeNull()
+    expect(
+      parseRequestBody({
+        url: 'url',
+        response: 'response',
+        params: { param: 'param' },
+      }),
+    ).toBeNull()
+    expect(
+      parseRequestBody({
+        url: 'url',
+        answer: 'answer',
+        params: { param: 'param' },
+      }),
+    ).toBeNull()
+    expect(
+      parseRequestBody({
+        url: 'url',
+        answer: 'answer',
+        response: 'response',
+      }),
+    ).toBeNull()
+  })
+})

src/handler.ts

@@ -0,0 +1,23 @@
+import axios from 'axios'
+
+import * as schema from './schema'
+
+export function parseRequestBody(body: unknown): {
+  url: string
+  evaluationFunctionRequestData: schema.EvaluationFunctionRequestData
+} | null {
+  const parseResult = schema.TestServerRequestData.safeParse(body)
+  if (!parseResult.success) return null
+
+  const { url, ...evaluationFunctionRequestData } = parseResult.data
+  return { url, evaluationFunctionRequestData }
+}
+
+export async function handleRawRequest(body: unknown): Promise<object | null> {
+  const parseResult = parseRequestBody(body)
+  if (parseResult == null) return null
+
+  const { url, evaluationFunctionRequestData } = parseResult
+  const response = await axios.post(url, evaluationFunctionRequestData)
+  return response.data
+}

src/index.ts

@@ -1,8 +1,9 @@
-import axios from 'axios'
 import cors from 'cors'
 import express from 'express'
 import dotenv from 'dotenv'
 
+import { handleRawRequest } from './handler'
+
 dotenv.config()
 
 const app = express()
@@ -11,14 +12,22 @@ app.use(cors())
 app.use(express.json())
 
 app.post('/', async (req, res) => {
-  console.log(`Received POST request:`, req.body)
-  const { url, ...params } = req.body
-  const response = await axios.post(url, params)
-  res.send(response.data)
+  console.log(`[INFO] Received POST request:`, req.body)
+  const responseData = await handleRawRequest(req.body)
+  if (responseData == null) {
+    console.log('[WARN] Invalid request received and ignored.')
+    res.status(400).send()
+  } else {
+    console.log(
+      '[INFO] Received response from evaluation function:',
+      responseData,
+    )
+    res.send(responseData)
+  }
 })
 
 const port = process.env.PORT ?? 3070
 
 app.listen(port, () => {
-  console.log(`Listening on port ${port}`)
+  console.log(`[INFO] Listening on port ${port}`)
 })

src/schema.ts

@@ -0,0 +1,17 @@
+import { z } from 'zod'
+
+export const EvaluationFunctionRequestData = z
+  .object({
+    answer: z.string(),
+    response: z.string(),
+    params: z.record(z.string(), z.any()),
+  })
+  .strict()
+export type EvaluationFunctionRequestData = z.infer<
+  typeof EvaluationFunctionRequestData
+>
+
+export const TestServerRequestData = EvaluationFunctionRequestData.extend({
+  url: z.string(),
+}).strict()
+export type TestServerRequestData = z.infer<typeof TestServerRequestData>

tsconfig.json

@@ -20,5 +20,6 @@
     "strict": true,
     "target": "es2016"
   },
-  "exclude": ["dist", "node_modules"]
+  "exclude": ["dist", "node_modules"],
+  "include": ["src"]
 }