cyclone/src/hooks/useRemitDetail.test.ts

// @vitest-environment happy-dom
// Mirror the IS_REACT_ACT_ENVIRONMENT setup from useClaimDetail.test.ts so
// React doesn't log act() warnings about the createRoot render/unmount.
(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;

import React, { act } from "react";
import { createRoot, type Root } from "react-dom/client";
import { describe, expect, it, vi, beforeEach } from "vitest";
import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
import { useRemitDetail } from "./useRemitDetail";
import { api, ApiError } from "@/lib/api";
import type { Remittance } from "@/types";

// Module-level mock: vitest hoists `vi.mock` above imports. We mock both
// `api.getRemittance` (the only method the hook calls) AND `ApiError`
// (the class used in the retry predicate) so that `instanceof ApiError`
// in the hook and `new ApiError(404, ...)` in the test resolve to the
// same class at runtime.
vi.mock("@/lib/api", () => {
  class ApiError extends Error {
    constructor(public status: number, message: string) {
      super(message);
    }
  }
  return {
    api: {
      getRemittance: vi.fn(),
    },
    ApiError,
  };
});

/**
 * Minimal renderHook shim — same pattern as `useClaimDetail.test.ts`.
 * The project doesn't ship `@testing-library/react`, so we wire a Probe
 * component into a real `createRoot` and read its return value through
 * a shared `result` object.
 */
function renderHook<TResult>(
  useCallback: () => TResult
): {
  result: { current: TResult | undefined };
  unmount: () => void;
} {
  const result: { current: TResult | undefined } = { current: undefined };
  const container = document.createElement("div");
  document.body.appendChild(container);
  const qc = new QueryClient({ defaultOptions: { queries: { retry: false } } });

  function Probe() {
    result.current = useCallback();
    return null;
  }

  const root: Root = createRoot(container);
  act(() => {
    root.render(
      React.createElement(QueryClientProvider, { client: qc }, React.createElement(Probe))
    );
  });

  return {
    result,
    unmount: () => {
      act(() => root.unmount());
      container.remove();
    },
  };
}

/** Poll the result until `predicate` is true or we time out. */
async function waitForState(
  predicate: () => boolean,
  timeoutMs = 1000
): Promise<void> {
  const start = Date.now();
  while (!predicate()) {
    if (Date.now() - start > timeoutMs) {
      throw new Error(`waitForState: predicate did not hold within ${timeoutMs}ms`);
    }
    await act(async () => {
      await Promise.resolve();
    });
  }
}

// Minimal valid Remittance — every required key present on the base
// `Remittance` interface. Mirrors the shape used by the page-level
// tests in `Remittances.test.tsx` so the type-checks line up with the
// rest of the codebase.
const SAMPLE_DETAIL: Remittance = {
  id: "REM-1",
  claimId: "CLM-1",
  payerName: "Medicaid",
  paidAmount: 100.0,
  adjustmentAmount: 20.0,
  receivedDate: "2026-01-15T00:00:00Z",
  checkNumber: "EFT-12345",
  status: "received",
};

describe("useRemitDetail", () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it("returns the empty drawer state and does not fetch when id is null", () => {
    // The drawer is closed → no network call, no loading, no error.
    // The hook must short-circuit BEFORE the queryFn is ever invoked.
    const { result, unmount } = renderHook(() => useRemitDetail(null));

    expect(result.current).toBeDefined();
    expect(result.current?.data).toBeNull();
    expect(result.current?.isLoading).toBe(false);
    expect(result.current?.isError).toBe(false);
    expect(result.current?.error).toBeNull();
    expect(typeof result.current?.refetch).toBe("function");
    expect(api.getRemittance).not.toHaveBeenCalled();

    unmount();
  });

  it("fetches the remit and returns the parsed body for a valid id", async () => {
    (api.getRemittance as unknown as ReturnType<typeof vi.fn>).mockResolvedValue(
      SAMPLE_DETAIL
    );

    const { result, unmount } = renderHook(() => useRemitDetail("REM-1"));

    await waitForState(
      () =>
        result.current?.data !== null &&
        result.current?.data !== undefined &&
        result.current?.isLoading === false
    );

    expect(result.current?.data).toEqual(SAMPLE_DETAIL);
    expect(result.current?.isError).toBe(false);
    expect(result.current?.error).toBeNull();
    expect(api.getRemittance).toHaveBeenCalledTimes(1);
    expect(api.getRemittance).toHaveBeenCalledWith("REM-1");

    unmount();
  });

  it("surfaces a 404 ApiError as isError=true with the original error object", async () => {
    // The hook's retry predicate must give up immediately on 404 — the
    // drawer needs to render the "remit doesn't exist" state rather than
    // masking it with three back-to-back retries.
    (api.getRemittance as unknown as ReturnType<typeof vi.fn>).mockRejectedValue(
      new ApiError(404, "Remittance ghost not found")
    );

    const { result, unmount } = renderHook(() => useRemitDetail("ghost"));

    await waitForState(() => result.current?.isError === true);

    expect(result.current?.data).toBeNull();
    expect(result.current?.isLoading).toBe(false);
    expect(result.current?.isError).toBe(true);
    expect(result.current?.error).toBeInstanceOf(ApiError);
    expect((result.current?.error as ApiError).status).toBe(404);
    // 404s must not retry — exactly one fetch attempt.
    expect(api.getRemittance).toHaveBeenCalledTimes(1);

    unmount();
  });
});