refactor(core): message tracker abstraction and formatter plugin registry

tests/message-tracker.test.ts

@@ -0,0 +1,59 @@
+import { describe, it, expect } from "bun:test";
+import { kvMessageTracker } from "../server/lib/lib/message-tracker";
+
+function createMockKV(): KVNamespace {
+  const store = new Map<string, string>();
+  const ttl = new Map<string, number>();
+  return {
+    get: async (key: string) => (store.has(key) ? store.get(key)! : null),
+    put: async (key: string, value: string, opts?: { expirationTtl?: number }) => {
+      store.set(key, value);
+      if (opts?.expirationTtl) ttl.set(key, opts.expirationTtl);
+    },
+    delete: async (key: string) => {
+      store.delete(key);
+    },
+    list: async () => ({ keys: [], list_complete: true, cacheStatus: null }),
+  } as unknown as KVNamespace;
+}
+
+describe("kvMessageTracker", () => {
+  it("stores and retrieves a message id by event and target", async () => {
+    const kv = createMockKV();
+    const tracker = kvMessageTracker(kv);
+    await tracker.set("route-1:workflow-9", "channel-1", "msg-42");
+    expect(await tracker.get("route-1:workflow-9", "channel-1")).toBe("msg-42");
+  });
+
+  it("returns null for an unknown event/target", async () => {
+    const kv = createMockKV();
+    const tracker = kvMessageTracker(kv);
+    expect(await tracker.get("missing", "channel-1")).toBeNull();
+  });
+
+  it("uses the msg:{eventId}:{targetId} key with a 7-day TTL", async () => {
+    const kv = createMockKV();
+    const keys = new Map<string, string>();
+    const ttls = new Map<string, number>();
+    (kv.put as unknown) = async (
+      key: string,
+      value: string,
+      opts?: { expirationTtl?: number },
+    ): Promise<void> => {
+      keys.set(key, value);
+      ttls.set(key, opts?.expirationTtl ?? 0);
+    };
+    const tracker = kvMessageTracker(kv);
+    await tracker.set("event-1", "target-1", "msg-7");
+    expect(keys.has("msg:event-1:target-1")).toBe(true);
+    expect(ttls.get("msg:event-1:target-1")).toBe(604800);
+  });
+
+  it("deletes tracked entries", async () => {
+    const kv = createMockKV();
+    const tracker = kvMessageTracker(kv);
+    await tracker.set("event-1", "target-1", "msg-7");
+    await tracker.delete("event-1", "target-1");
+    expect(await tracker.get("event-1", "target-1")).toBeNull();
+  });
+});