@reckona/mreact-test-utils

@reckona/mreact-test-utils provides compact integration-test helpers for the mreact app router and component-level reactive DOM tests. It wraps temporary app directories, request helpers, reactive update flushing, and HTML assertions.

Basic Usage

import { createAppFixture, responseText } from "@reckona/mreact-test-utils";

const fixture = await createAppFixture({
  files: {
    "page.tsx": "export default function Page() { return <main>Hello</main>; }",
  },
});

const response = await fixture.render("/");
const html = await responseText(response);

For component-level tests, mount reactive DOM output directly and use act() to flush pending reactive work:

import { bindText } from "@reckona/mreact-reactive-dom";
import { act, createCellMock, render } from "@reckona/mreact-test-utils";

const count = createCellMock(0);
const view = render(() => {
  const text = document.createTextNode("");
  bindText(text, () => count.get());
  return text;
});

await act(() => {
  count.set(1);
});

view.container.textContent;
// "1"

For unit tests that call app-router route handlers directly, use invokeRouteHandler() to translate mreact control-flow throws into the same Response objects the router boundary would produce:

import { redirect } from "@reckona/mreact-router";
import { invokeRouteHandler } from "@reckona/mreact-test-utils";

function POST(request: Request): Response {
  if (!request.headers.get("cookie")) redirect("/login");
  return Response.json({ ok: true });
}

const response = await invokeRouteHandler(POST, new Request("https://app.test/api", { method: "POST" }));
response.status;
// 303

Core APIs

• createAppFixture() creates a temporary app and .mreact/ build output.
• fixture.render() sends requests through the router using Request / Response.
• fixture.write() adds or updates route files in the fixture app.
• render() mounts reactive DOM output into a container and returns { container, rerender, unmount }.
• act() runs sync or async mutations and waits for reactive effects to settle.
• flushReactive() drains pending reactive effects without wrapping a mutation.
• createCellMock() and createComputedMock() create real reactive primitives for focused unit tests.
• invokeRouteHandler() calls a route handler and converts redirect(), notFound(), and thrown Response control flow into a Response.
• responseText() reads a response body as a string.

Use Cases

Use this package for scenario tests that cross router, query, auth, forms, and server-action boundaries. Because this repository is a public library, test scenario names should be specific and written in English.