Initial commit

dist/shared/middleware/idempotency.js

@@ -0,0 +1,37 @@
+import { ApiError } from "../errors";
+import { readIdempotency, writeIdempotency } from "../idempotency/idempotencyStore";
+import { env } from "../../config/env";
+export function idempotency(options) {
+    return function idempotencyMiddleware(req, _res, next) {
+        const idempotencyKey = req.header("idempotency-key");
+        if (!idempotencyKey) {
+            if (options.required === false) {
+                return next();
+            }
+            return next(new ApiError("DUPLICATE_REQUEST", "Missing Idempotency-Key", 400));
+        }
+        const cached = readIdempotency(options.scope, idempotencyKey);
+        if (cached) {
+            const cachedPayload = cached.response ?? cached;
+            const cachedStatus = cached.statusCode || 200;
+            return _res.status(cachedStatus).json(cachedPayload);
+        }
+        req.body = { ...(req.body || {}), __idempotencyKey: idempotencyKey };
+        const originalJson = _res.json.bind(_res);
+        const originalStatus = _res.status.bind(_res);
+        let statusCode = 200;
+        _res.status = function statusWithStore(code) {
+            statusCode = code;
+            return originalStatus(code);
+        };
+        _res.json = function jsonWithStore(payload) {
+            writeIdempotency(options.scope, idempotencyKey, {
+                response: payload,
+                statusCode,
+                at: Date.now()
+            }, options.ttlMs || env.IDEMPOTENCY_TTL_MS);
+            return originalJson(payload);
+        };
+        next();
+    };
+}