feat: implement idempotency middleware with pure ASGI

verify_idempotency.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+set -e
+
+echo "Logging in..."
+TOKEN=$(curl -s -X POST -H "Content-Type: application/json" -d '{"email":"test@example.com", "password":"password123"}' http://localhost:8000/auth/login | jq -r .access_token)
+echo "Token obtained."
+
+echo "Getting Chest ID..."
+CHEST_ID=$(curl -s http://localhost:8000/catalog/chests | jq -r '.[0].id')
+echo "Chest ID: $CHEST_ID"
+
+KEY="idempotency-test-$(date +%s)"
+
+echo "--- Request 1 (Key: $KEY) ---"
+RESP1=$(curl -s -X POST -H "Authorization: Bearer $TOKEN" -H "Idempotency-Key: $KEY" http://localhost:8000/chests/$CHEST_ID/open)
+echo "Response 1: $RESP1"
+
+BALANCE1=$(curl -s -H "Authorization: Bearer $TOKEN" http://localhost:8000/me/wallet | jq -r .balance)
+echo "Balance after 1st request: $BALANCE1"
+
+echo "--- Request 2 (Key: $KEY - Retry) ---"
+RESP2=$(curl -s -X POST -H "Authorization: Bearer $TOKEN" -H "Idempotency-Key: $KEY" http://localhost:8000/chests/$CHEST_ID/open)
+echo "Response 2: $RESP2"
+
+BALANCE2=$(curl -s -H "Authorization: Bearer $TOKEN" http://localhost:8000/me/wallet | jq -r .balance)
+echo "Balance after 2nd request: $BALANCE2"
+
+if [ "$RESP1" == "$RESP2" ]; then
+    echo "SUCCESS: Responses are identical."
+else
+    echo "FAILURE: Responses differ."
+    exit 1
+fi
+
+if [ "$BALANCE1" == "$BALANCE2" ]; then
+    echo "SUCCESS: Balance did not change on retry."
+else
+    echo "FAILURE: Balance changed on retry!"
+    exit 1
+fi
+
+KEY_NEW="idempotency-test-new-$(date +%s)"
+echo "--- Request 3 (New Key: $KEY_NEW) ---"
+RESP3=$(curl -s -X POST -H "Authorization: Bearer $TOKEN" -H "Idempotency-Key: $KEY_NEW" http://localhost:8000/chests/$CHEST_ID/open)
+echo "Response 3: $RESP3"
+
+BALANCE3=$(curl -s -H "Authorization: Bearer $TOKEN" http://localhost:8000/me/wallet | jq -r .balance)
+echo "Balance after 3rd request: $BALANCE3"
+
+if [ "$BALANCE3" -lt "$BALANCE2" ]; then
+    echo "SUCCESS: Balance decreased on new request."
+else
+    echo "FAILURE: Balance did not decrease on new request."
+    exit 1
+fi
+
+echo "ALL TESTS PASSED"