feat(FN-4921): merge fusion/fn-4921

packages/dashboard/app/utils/__tests__/dashboardTraceBuffer.test.ts

@@ -0,0 +1,47 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { beforeEach, describe, expect, it } from "vitest";
+import { clearTraces, getTraces, pushTrace } from "../dashboardTraceBuffer";
+
+describe("dashboardTraceBuffer", () => {
+  beforeEach(() => {
+    clearTraces();
+  });
+
+  it("appends trace entries", () => {
+    pushTrace("versionCheck", "mismatch", { local: "a", remote: "b" });
+
+    const traces = getTraces();
+    expect(traces).toHaveLength(1);
+    expect(traces[0]).toMatchObject({
+      source: "versionCheck",
+      event: "mismatch",
+      detail: { local: "a", remote: "b" },
+    });
+    expect(typeof traces[0].ts).toBe("string");
+  });
+
+  it("caps entries at 200 and drops oldest", () => {
+    for (let i = 0; i < 205; i += 1) {
+      pushTrace("sse-bus", "event", { idx: i });
+    }
+
+    const traces = getTraces();
+    expect(traces).toHaveLength(200);
+    expect(traces[0]?.detail).toEqual({ idx: 5 });
+    expect(traces[199]?.detail).toEqual({ idx: 204 });
+  });
+
+  it("exposes traces via window.__fusionDebug.dashboardTraces.get", () => {
+    pushTrace("useTasks", "dropped-stale-event", { count: 1 });
+
+    const debugApi = window.__fusionDebug?.dashboardTraces;
+    expect(debugApi).toBeDefined();
+    expect(debugApi?.get()).toHaveLength(1);
+    expect(debugApi?.get()[0]).toMatchObject({
+      source: "useTasks",
+      event: "dropped-stale-event",
+    });
+  });
+});

packages/dashboard/app/utils/dashboardTraceBuffer.ts

@@ -0,0 +1,49 @@
+export type TraceEntry = {
+  ts: string;
+  source: string;
+  event: string;
+  detail: Record<string, unknown>;
+};
+
+const TRACE_CAP = 200;
+const traces: TraceEntry[] = [];
+
+export function pushTrace(source: string, event: string, detail: Record<string, unknown>): void {
+  traces.push({
+    ts: new Date().toISOString(),
+    source,
+    event,
+    detail,
+  });
+
+  if (traces.length > TRACE_CAP) {
+    traces.splice(0, traces.length - TRACE_CAP);
+  }
+}
+
+export function getTraces(): TraceEntry[] {
+  return [...traces];
+}
+
+export function clearTraces(): void {
+  traces.length = 0;
+}
+
+declare global {
+  interface Window {
+    __fusionDebug?: {
+      dashboardTraces?: {
+        get: typeof getTraces;
+        clear: typeof clearTraces;
+      };
+    };
+  }
+}
+
+if (typeof window !== "undefined") {
+  window.__fusionDebug ??= {};
+  window.__fusionDebug.dashboardTraces = {
+    get: getTraces,
+    clear: clearTraces,
+  };
+}