useCache.test.mjs

// @ts-check

import { deepStrictEqual, ok, strictEqual } from "node:assert";
import { describe, it } from "node:test";

import React from "react";
import ReactTestRenderer from "react-test-renderer";

import Cache from "./Cache.mjs";
import CacheContext from "./CacheContext.mjs";
import assertBundleSize from "./test/assertBundleSize.mjs";
import createReactTestRenderer from "./test/createReactTestRenderer.mjs";
import ReactHookTest from "./test/ReactHookTest.mjs";
import useCache from "./useCache.mjs";

describe("React hook `useCache`.", { concurrency: true }, () => {
  it("Bundle size.", async () => {
    await assertBundleSize(new URL("./useCache.mjs", import.meta.url), 350);
  });

  it("Cache context missing.", () => {
    /** @type {Array<import("./test/ReactHookTest.mjs").ReactHookResult>} */
    const results = [];

    createReactTestRenderer(
      React.createElement(ReactHookTest, {
        useHook: useCache,
        results,
      }),
    );

    strictEqual(results.length, 1);
    ok("threw" in results[0]);
    deepStrictEqual(results[0].threw, new TypeError("Cache context missing."));
  });

  it("Cache context value not a `Cache` instance.", () => {
    /** @type {Array<import("./test/ReactHookTest.mjs").ReactHookResult>} */
    const results = [];

    createReactTestRenderer(
      React.createElement(
        CacheContext.Provider,
        {
          // @ts-expect-error Testing invalid.
          value: true,
        },
        React.createElement(ReactHookTest, {
          useHook: useCache,
          results,
        }),
      ),
    );

    strictEqual(results.length, 1);
    ok("threw" in results[0]);
    deepStrictEqual(
      results[0].threw,
      new TypeError("Cache context value must be a `Cache` instance."),
    );
  });

  it("Getting the cache.", () => {
    const cacheA = new Cache();

    /** @type {Array<import("./test/ReactHookTest.mjs").ReactHookResult>} */
    const results = [];

    const testRenderer = createReactTestRenderer(
      React.createElement(
        CacheContext.Provider,
        { value: cacheA },
        React.createElement(ReactHookTest, {
          useHook: useCache,
          results,
        }),
      ),
    );

    strictEqual(results.length, 1);
    ok("returned" in results[0]);
    strictEqual(results[0].returned, cacheA);

    const cacheB = new Cache();

    ReactTestRenderer.act(() => {
      testRenderer.update(
        React.createElement(
          CacheContext.Provider,
          { value: cacheB },
          React.createElement(ReactHookTest, {
            useHook: useCache,
            results,
          }),
        ),
      );
    });

    strictEqual(results.length, 2);
    ok("returned" in results[1]);
    strictEqual(results[1].returned, cacheB);
  });
});