Add test suite for CORS and CSP validation in Express app

test-backend/test/run-tests.ts

@@ -0,0 +1,63 @@
+import http from "http"
+import fetch from "node-fetch"
+import app from "../app"
+
+async function listenOnRandomPort() {
+  return new Promise<{ server: http.Server; port: number }>(
+    (resolve, reject) => {
+      const server = http.createServer(app)
+      server.listen(0, () => {
+        // @ts-ignore
+        const addr = server.address()
+        if (!addr || typeof addr === "string")
+          return reject(new Error("Failed to get server address"))
+        resolve({ server, port: addr.port })
+      })
+    }
+  )
+}
+
+async function run() {
+  const FRONTEND = process.env.FRONTEND_URL || "http://localhost:5173"
+  const { server, port } = await listenOnRandomPort()
+  const base = `http://localhost:${port}`
+
+  try {
+    // 1) Allowed origin
+    const allowed = await fetch(base + "/api/meters", {
+      headers: { Origin: FRONTEND },
+    })
+    console.log("Allowed origin status:", allowed.status)
+    const csp = allowed.headers.get("content-security-policy")
+    const nonce = allowed.headers.get("x-csp-nonce")
+    console.log("CSP header present:", !!csp)
+    console.log("X-CSP-Nonce present:", !!nonce)
+
+    if (allowed.status !== 200) throw new Error("Allowed origin request failed")
+    if (!csp) throw new Error("CSP header missing")
+    if (!nonce) throw new Error("X-CSP-Nonce missing")
+
+    // 2) Disallowed origin
+    const disallowed = await fetch(base + "/api/meters", {
+      headers: { Origin: "https://evil.com" },
+    })
+    console.log("Disallowed origin status:", disallowed.status)
+    if (disallowed.status !== 403)
+      throw new Error("Disallowed origin not rejected")
+
+    // 3) Missing origin -> should be rejected now
+    const missing = await fetch(base + "/api/meters")
+    console.log("Missing origin status:", missing.status)
+    if (missing.status !== 403)
+      throw new Error("Request without Origin header should be rejected")
+
+    console.log("\nAll tests passed")
+  } catch (err) {
+    console.error("Test failure:", err)
+    process.exitCode = 1
+  } finally {
+    server.close()
+  }
+}
+
+run()