import { describe, expect, it } from "vitest";
import {
  applyNotificationPreferencePatch,
  deriveNotificationPreferencePatch,
  rollbackNotificationPreferencePatch,
} from "./patch";

describe("notification preference patches", () => {
  it("sends only the changed key when another muted preference is present", () => {
    expect(
      deriveNotificationPreferencePatch(
        { status_changes: "muted" },
        { status_changes: "muted", comments: "muted" },
      ),
    ).toEqual({ comments: "muted" });
  });

  it("uses an explicit all value when enabling a previously muted group", () => {
    expect(
      deriveNotificationPreferencePatch(
        { status_changes: "muted", comments: "muted" },
        { comments: "muted" },
      ),
    ).toEqual({ status_changes: "all" });
  });

  it("merges optimistic patches without dropping unrelated preferences", () => {
    expect(
      applyNotificationPreferencePatch(
        { status_changes: "muted" },
        { comments: "muted" },
      ),
    ).toEqual({ status_changes: "muted", comments: "muted" });
  });

  it("does not roll back a key that a later mutation already changed", () => {
    expect(
      rollbackNotificationPreferencePatch(
        { comments: "muted" },
        { comments: "muted" },
        {},
      ),
    ).toEqual({});

    expect(
      rollbackNotificationPreferencePatch(
        {},
        { comments: "muted" },
        {},
      ),
    ).toEqual({});
  });
});