feat(offline): add IndexedDB mutation queue (enqueue, dequeue, mark synced/conflict)

src/lib/offline/queue.test.ts

@@ -0,0 +1,64 @@
+// @vitest-environment jsdom
+// src/lib/offline/queue.test.ts
+import { describe, it, expect, beforeEach } from "vitest";
+import "fake-indexeddb/auto";
+import { enqueueAction, dequeueAction, getQueuedActions, markSynced, markConflict } from "./queue";
+
+beforeEach(async () => {
+  // Clear the queue between tests
+  const { getOfflineDB } = await import("./db");
+  const db = await getOfflineDB();
+  await db.clear("queue");
+});
+
+describe("offline queue", () => {
+  it("enqueueAction stores an action with a generated clientActionId", async () => {
+    const action = await enqueueAction("markOrderReady", { orderId: "abc" });
+    expect(action.id).toMatch(/^[0-9a-f-]{36}$/i);
+    expect(action.actionName).toBe("markOrderReady");
+    expect(action.status).toBe("pending");
+    expect(action.attempts).toBe(0);
+  });
+
+  it("enqueueAction is idempotent on the same clientActionId", async () => {
+    const a = await enqueueAction("markOrderReady", { orderId: "abc" }, { id: "fixed-id" });
+    const b = await enqueueAction("markOrderReady", { orderId: "abc" }, { id: "fixed-id" });
+    expect(a.id).toBe(b.id);
+    expect(a.id).toBe("fixed-id");
+    const all = await getQueuedActions();
+    expect(all).toHaveLength(1);
+  });
+
+  it("getQueuedActions returns pending actions in createdAt order", async () => {
+    const a = await enqueueAction("a", {}, { id: "a" });
+    // Small delay to ensure ordering
+    await new Promise((r) => setTimeout(r, 5));
+    const b = await enqueueAction("b", {}, { id: "b" });
+    const all = await getQueuedActions();
+    expect(all.map((x) => x.id)).toEqual([a.id, b.id]);
+  });
+
+  it("dequeueAction removes the action and returns its data", async () => {
+    const a = await enqueueAction("markOrderReady", { orderId: "abc" });
+    const removed = await dequeueAction(a.id);
+    expect(removed?.id).toBe(a.id);
+    const all = await getQueuedActions();
+    expect(all).toHaveLength(0);
+  });
+
+  it("markSynced removes the action", async () => {
+    const a = await enqueueAction("markOrderReady", { orderId: "abc" });
+    await markSynced(a.id);
+    const all = await getQueuedActions();
+    expect(all).toHaveLength(0);
+  });
+
+  it("markConflict moves the action to conflict status", async () => {
+    const a = await enqueueAction("markOrderReady", { orderId: "abc" });
+    await markConflict(a.id, "stale updated_at");
+    const all = await getQueuedActions();
+    expect(all).toHaveLength(1);
+    expect(all[0].status).toBe("conflict");
+    expect(all[0].error).toBe("stale updated_at");
+  });
+});