feat(clouddevice): add opt-in retry for transient socket drops

src/__tests__/cloudDevice/cloudDeviceApi.spec.ts

@@ -141,6 +141,42 @@ describe("CloudDeviceApi baseUrl", (): void => {
 });
 
 describe("CloudDeviceApi", (): void => {
+    test("retries an opted-in socket drop with the identical Nexo payload", async (): Promise<void> => {
+        const requestBodies: string[] = [];
+        const endpoint = `/merchants/${merchantAccount}/devices/${deviceId}/sync`;
+        scope
+            .post(endpoint, (body) => {
+                requestBodies.push(JSON.stringify(body));
+                return true;
+            })
+            .replyWithError({ message: "socket hang up" })
+            .post(endpoint, (body) => {
+                requestBodies.push(JSON.stringify(body));
+                return true;
+            })
+            .reply(200, paymentSyncSuccess);
+
+        const request = createCloudDeviceApiPaymentRequest();
+        await cloudDeviceAPI.CloudDeviceApi.sync(merchantAccount, deviceId, request, { retries: 1 });
+
+        expect(requestBodies).toHaveLength(2);
+        expect(requestBodies[1]).toBe(requestBodies[0]);
+        expect(JSON.parse(requestBodies[1]).SaleToPOIRequest.MessageHeader.ServiceID)
+            .toBe(request.SaleToPOIRequest.MessageHeader.ServiceID);
+    });
+
+    test("does not retry an HTTP error", async (): Promise<void> => {
+        const endpoint = `/merchants/${merchantAccount}/devices/${deviceId}/sync`;
+        const requestScope = scope
+            .post(endpoint)
+            .reply(500, { status: 500, message: "server error" });
+
+        const request = createCloudDeviceApiPaymentRequest();
+        await expect(cloudDeviceAPI.CloudDeviceApi.sync(merchantAccount, deviceId, request, { retries: 1 }))
+            .rejects.toThrow();
+        expect(requestScope.isDone()).toBe(true);
+    });
+
     test("should send a sync payment request", async (): Promise<void> => {
         scope
             .post(`/merchants/${merchantAccount}/devices/${deviceId}/sync`)

src/__tests__/cloudDevice/encryptedCloudDeviceApi.spec.ts

@@ -95,6 +95,31 @@ afterEach(() => {
 });
 
 describe("EncryptedCloudDeviceApi", () => {
+    test("retries an opted-in socket drop with the identical encrypted Nexo payload", async () => {
+        const requestBodies: string[] = [];
+        const endpoint = `/merchants/${merchantAccount}/devices/${deviceId}/sync`;
+        nock(BASE_URL)
+            .post(endpoint, (body) => {
+                requestBodies.push(JSON.stringify(body));
+                return true;
+            })
+            .replyWithError({ message: "socket hang up" })
+            .post(endpoint, (body) => {
+                requestBodies.push(JSON.stringify(body));
+                return true;
+            })
+            .reply(200, paymentSyncEncryptedSuccess);
+
+        const api = new EncryptedCloudDeviceApi(client, DEFAULT_CREDENTIALS);
+        const request = createCloudDeviceApiPaymentRequest();
+        await api.sync(merchantAccount, deviceId, request, { retries: 1 });
+
+        expect(requestBodies).toHaveLength(2);
+        expect(requestBodies[1]).toBe(requestBodies[0]);
+        expect(JSON.parse(requestBodies[1]).SaleToPOIRequest.MessageHeader.ServiceID)
+            .toBe(request.SaleToPOIRequest.MessageHeader.ServiceID);
+    });
+
     test("sendEncryptedSync - encrypts request and decrypts response", async () => {
         let capturedBody = "";
         nock(BASE_URL)

src/httpClient/httpURLConnectionClient.ts

@@ -285,7 +285,7 @@ class HttpURLConnectionClient implements ClientInterface {
             connectionRequest.on("timeout", (): void => {
                 connectionRequest.abort();
             });
-            connectionRequest.on("error", (e) => reject(new ApiException(e.message)));
+            connectionRequest.on("error", (e: NodeJS.ErrnoException) => reject(new ApiException(e.message, 500, e.code)));
             connectionRequest.write(json);
             connectionRequest.end();
         });

src/services/clouddevice/cloudDeviceApi.ts

@@ -17,11 +17,12 @@
  * See the LICENSE file for more info.
  */
 
-import getJsonResponse from "../../helpers/getJsonResponse";
 import Service from "../../service";
 import Client from "../../client";
+import getJsonResponse from "../../helpers/getJsonResponse";
 import { IRequest } from "../../typings/requestOptions";
 import Resource from "../resource";
+import requestWithRetries from "./requestWithRetries";
 import { CloudDeviceApiAsyncResponse } from "../../typings/clouddevice/models";
 import { CloudDeviceApiRequest } from "../../typings/clouddevice/models";
 import { CloudDeviceApiResponse } from "../../typings/clouddevice/models";
@@ -54,10 +55,10 @@ export class CloudDeviceApi extends Service {
             .replace("{" + "merchantAccount" + "}", encodeURIComponent(String(merchantAccount)))
             .replace("{" + "deviceId" + "}", encodeURIComponent(String(deviceId)));
         const resource = new Resource(this, endpoint);
-        const response = await getJsonResponse<CloudDeviceApiRequest, CloudDeviceApiResponse>(
+        const response = await requestWithRetries<CloudDeviceApiRequest, CloudDeviceApiResponse>(
             resource,
-            cloudDeviceApiRequest,
-            { ...requestOptions, method: "POST" }
+            JSON.stringify(cloudDeviceApiRequest),
+            { ...requestOptions, method: "POST" },
         );
         return response;
     }
@@ -75,10 +76,10 @@ export class CloudDeviceApi extends Service {
             .replace("{" + "merchantAccount" + "}", encodeURIComponent(String(merchantAccount)))
             .replace("{" + "deviceId" + "}", encodeURIComponent(String(deviceId)));
         const resource = new Resource(this, endpoint);
-        const response = await getJsonResponse<CloudDeviceApiRequest, string>(
+        const response = await requestWithRetries<CloudDeviceApiRequest, string>(
             resource,
-            cloudDeviceApiRequest,
-            { ...requestOptions, method: "POST" }
+            JSON.stringify(cloudDeviceApiRequest),
+            { ...requestOptions, method: "POST" },
         );
         const result = new CloudDeviceApiAsyncResponse();
         if (typeof response === "string" && response.toLowerCase().trim() === "ok") {

src/services/clouddevice/encryptedCloudDeviceApi.ts

@@ -17,7 +17,6 @@
  * See the LICENSE file for more info.
  */
 
-import getJsonResponse from "../../helpers/getJsonResponse";
 import Service from "../../service";
 import Client from "../../client";
 import { IRequest } from "../../typings/requestOptions";
@@ -30,6 +29,7 @@ import { CloudDeviceApiSecuredResponse } from "../../typings/clouddevice/cloudDe
 import { EncryptionCredentialDetails } from "../../security/clouddevice/encryptionCredentialDetails";
 import { NexoSecurityManager } from "../../security/clouddevice/nexoSecurityManager";
 import { NexoSecurityException } from "../../security/clouddevice/nexoSecurityException";
+import requestWithRetries from "./requestWithRetries";
 
 /**
  * Cloud Device API service with encrypted payloads.
@@ -84,9 +84,9 @@ export class EncryptedCloudDeviceApi extends Service {
             .replace("{deviceId}", encodeURIComponent(deviceId));
         const resource = new Resource(this, endpoint);
 
-        const response = await getJsonResponse<CloudDeviceApiSecuredRequest, CloudDeviceApiSecuredResponse>(
+        const response = await requestWithRetries<CloudDeviceApiSecuredRequest, CloudDeviceApiSecuredResponse>(
             resource,
-            securedRequest,
+            JSON.stringify(securedRequest),
             { ...requestOptions, method: "POST" },
         );
 
@@ -139,9 +139,9 @@ export class EncryptedCloudDeviceApi extends Service {
             .replace("{deviceId}", encodeURIComponent(deviceId));
         const resource = new Resource(this, endpoint);
 
-        const response = await getJsonResponse<CloudDeviceApiSecuredRequest, string>(
+        const response = await requestWithRetries<CloudDeviceApiSecuredRequest, string>(
             resource,
-            securedRequest,
+            JSON.stringify(securedRequest),
             { ...requestOptions, method: "POST" },
         );
 

src/services/clouddevice/requestWithRetries.ts

@@ -0,0 +1,35 @@
+import getJsonResponse from "../../helpers/getJsonResponse";
+import Resource from "../resource";
+import { IRequest } from "../../typings/requestOptions";
+import ApiException from "../exception/apiException";
+
+const MAX_CLOUD_DEVICE_RETRIES = 3;
+
+const isRetryableTransportError = (error: unknown): boolean => {
+    if (!(error instanceof ApiException)) {
+        return false;
+    }
+
+    return error.code === "ECONNRESET" || error.message.includes("socket hang up");
+};
+
+export default async function requestWithRetries<T, R>(
+    resource: Resource,
+    requestBody: string,
+    requestOptions: IRequest.Options = {},
+): Promise<R> {
+    const { retries = 0, ...httpOptions } = requestOptions;
+    const retryLimit = Number.isFinite(retries)
+        ? Math.min(MAX_CLOUD_DEVICE_RETRIES, Math.max(0, Math.floor(retries)))
+        : 0;
+
+    for (let attempt = 0; ; attempt++) {
+        try {
+            return await getJsonResponse<T, R>(resource, requestBody, httpOptions);
+        } catch (error) {
+            if (attempt >= retryLimit || !isRetryableTransportError(error)) {
+                throw error;
+            }
+        }
+    }
+}

src/services/exception/apiException.ts

@@ -22,13 +22,15 @@ import { ApiError } from "../../typings/apiError";
 class ApiException implements Error {
     public error!: ApiError;
     public statusCode: number;
+    public readonly code?: string;
     public readonly message: string;
     public readonly name: string;
 
-    public constructor(message: string, statusCode = 500) {
+    public constructor(message: string, statusCode = 500, code?: string) {
         this.name = "ApiException";
         this.message = message;
         this.statusCode = statusCode;
+        this.code = code;
     }
 }
 

src/typings/requestOptions.ts

@@ -28,6 +28,6 @@ export namespace IRequest {
     export type Options = https.RequestOptions & {
         idempotencyKey?: string;
         params?: QueryString;
+        retries?: number;
     };
 }
-