Introduce retry updater

src/lib/device/retry_updater.test.ts

@@ -0,0 +1,57 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Tendry Lab
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, test, expect } from "vitest";
+
+import { Updater } from "@device-ui/lib/device/updater";
+import { RetryUpdater } from "@device-ui/lib/device/retry_updater";
+
+class TestUpdater implements Updater {
+  constructor(
+    private error: Error | null,
+    private errorRetryCount: number = -1,
+  ) {}
+
+  async update(data: Uint8Array): Promise<Error | null> {
+    const error: Error | null = this.error;
+
+    if (this.errorRetryCount > 0) {
+      this.errorRetryCount--;
+    }
+    if (!this.errorRetryCount) {
+      this.error = null;
+    }
+
+    return error;
+  }
+}
+
+describe("Retry Updater", () => {
+  test("Faile to update with retries", async () => {
+    const updateError: Error = new Error("unable to update");
+    const retryCount: number = 3;
+
+    const testUpdater: TestUpdater = new TestUpdater(updateError, retryCount);
+    const retryUpdater: Updater = new RetryUpdater(testUpdater, retryCount);
+
+    expect(await retryUpdater.update(new Uint8Array([1, 2, 3, 4, 5]))).toEqual(
+      updateError,
+    );
+  });
+  test("Successfully update after retries", async () => {
+    const updateError: Error = new Error("unable to update");
+    const retryCount: number = 3;
+
+    const testUpdater: TestUpdater = new TestUpdater(
+      updateError,
+      retryCount - 1,
+    );
+    const retryUpdater: Updater = new RetryUpdater(testUpdater, retryCount);
+
+    expect(
+      await retryUpdater.update(new Uint8Array([1, 2, 3, 4, 5])),
+    ).toBeNull();
+  });
+});

src/lib/device/retry_updater.ts

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Tendry Lab
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { Updater } from "@device-ui/lib/device/updater";
+
+export class RetryUpdater implements Updater {
+  // Initialize.
+  //
+  // @params
+  //  - @p updater to handle the actual update process.
+  //  - @p retryCount - number of times to retry update process in case of error.
+  constructor(
+    private updater: Updater,
+    private retryCount: number,
+  ) {}
+
+  // Update with retries.
+  async update(data: Uint8Array) {
+    let error: Error | null = null;
+
+    for (let n: number = 0; n < this.retryCount; n++) {
+      error = await this.updater.update(data);
+      if (!error) {
+        break;
+      }
+    }
+
+    return error;
+  }
+}