chore: import upstream snapshot with attribution

tests/unit/ui/CompressionHub-patch-only.test.tsx

@@ -0,0 +1,153 @@
+// @vitest-environment jsdom
+/**
+ * Guards fix for issue #6039:
+ * CompressionHub was sending the full merged settings object to PUT
+ * /api/settings/compression instead of only the patch. The API schema uses
+ * .strict() Zod validation, so any field present in CompressionConfig but
+ * absent from compressionSettingsUpdateSchema (e.g. contextBudget, or
+ * stackedPipeline steps using engines not yet in the discriminated union)
+ * would cause a 400 validation failure — making switching to any non-default
+ * combo fail silently.
+ *
+ * Fix: send `patch` (the caller-supplied partial update) instead of `next`
+ * (the full optimistically-merged state).
+ */
+
+import React from "react";
+import { act } from "react";
+import { createRoot } from "react-dom/client";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+// ── Mocks ─────────────────────────────────────────────────────────────────────
+
+// Stub next/navigation (not used by CompressionHub but required by module graph)
+vi.mock("next/navigation", () => ({
+  useRouter: () => ({ push: vi.fn() }),
+  usePathname: () => "/",
+}));
+
+// Track all fetch calls
+const fetchCalls: { url: string; init: RequestInit }[] = [];
+const mockFetch = vi.fn().mockImplementation((url: string, init: RequestInit) => {
+  fetchCalls.push({ url, init });
+  return Promise.resolve({
+    ok: true,
+    json: async () => ({ combos: [] }),
+  });
+});
+vi.stubGlobal("fetch", mockFetch);
+
+// Import after mocks are in place
+import CompressionHub from "../../../src/app/(dashboard)/dashboard/context/combos/CompressionHub";
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+function getLastPutBody(): Record<string, unknown> | null {
+  const putCall = [...fetchCalls].reverse().find(
+    (c) => c.init?.method === "PUT"
+  );
+  if (!putCall) return null;
+  return JSON.parse(putCall.init.body as string);
+}
+
+// ── Tests ─────────────────────────────────────────────────────────────────────
+
+describe("CompressionHub — PUT sends patch only, not full settings", () => {
+  let container: HTMLDivElement;
+  let root: ReturnType<typeof createRoot>;
+
+  beforeEach(() => {
+    fetchCalls.length = 0;
+    mockFetch.mockClear();
+
+    // GET /api/settings/compression returns a config with extra fields that
+    // are NOT in compressionSettingsUpdateSchema (simulates contextBudget etc.)
+    mockFetch.mockImplementationOnce((_url: string) =>
+      Promise.resolve({
+        ok: true,
+        json: async () => ({
+          enabled: true,
+          defaultMode: "lite",
+          activeComboId: null,
+          contextEditing: { enabled: false },
+          // Field present in CompressionConfig but NOT in the update schema:
+          contextBudget: { mode: "floor", floorTokens: 4096 },
+          // Engine step type not in stackedPipelineStepSchema discriminated union:
+          stackedPipeline: [
+            { engine: "headroom", intensity: "standard" },
+            { engine: "caveman", intensity: "lite" },
+          ],
+        }),
+      })
+    );
+
+    // GET /api/settings/compression/combos
+    mockFetch.mockImplementationOnce((_url: string) =>
+      Promise.resolve({
+        ok: true,
+        json: async () => ({ combos: [{ id: "c1", name: "My Combo", pipeline: [] }] }),
+      })
+    );
+
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+  });
+
+  afterEach(() => {
+    act(() => { root.unmount(); });
+    document.body.removeChild(container);
+  });
+
+  it("sends only the changed field when activeComboId is updated", async () => {
+    await act(async () => {
+      root.render(<CompressionHub />);
+    });
+
+    // Find the combo selector and change it to "c1"
+    const select = container.querySelector("select");
+    expect(select).not.toBeNull();
+
+    await act(async () => {
+      if (select) {
+        Object.defineProperty(select, "value", { writable: true, value: "c1" });
+        select.dispatchEvent(new Event("change", { bubbles: true }));
+      }
+    });
+
+    const body = getLastPutBody();
+    expect(body).not.toBeNull();
+
+    // Must contain the changed field
+    expect(body).toHaveProperty("activeComboId", "c1");
+
+    // Must NOT contain fields from the full settings that would fail strict
+    // schema validation (contextBudget, stackedPipeline with unknown engines)
+    expect(body).not.toHaveProperty("contextBudget");
+    expect(body).not.toHaveProperty("stackedPipeline");
+    expect(body).not.toHaveProperty("enabled");
+    expect(body).not.toHaveProperty("defaultMode");
+  });
+
+  it("sends only the toggle field when contextEditing is toggled", async () => {
+    await act(async () => {
+      root.render(<CompressionHub />);
+    });
+
+    // Find the context editing toggle button
+    const toggleButtons = container.querySelectorAll("button[role='switch']");
+    expect(toggleButtons.length).toBeGreaterThan(0);
+
+    await act(async () => {
+      (toggleButtons[0] as HTMLButtonElement).click();
+    });
+
+    const body = getLastPutBody();
+    expect(body).not.toBeNull();
+
+    // Should only include contextEditing, not the full settings
+    expect(body).toHaveProperty("contextEditing");
+    expect(body).not.toHaveProperty("contextBudget");
+    expect(body).not.toHaveProperty("stackedPipeline");
+  });
+});