portifolio-evandrodevbr/lib/device.paths.test.ts

import { readFileSync } from "node:fs";
import { join } from "node:path";
import ts from "typescript";
import {
  isCoarsePointer,
  isLowPowerDevice,
  isMobileViewport,
  isSaveData,
  prefersReducedMotion,
} from "./device";

/**
 * Testes de caminhos-base de lib/device.ts (complemento de device.test.ts): matches() sem matchMedia,
 * cada condição de isLowPowerDevice isolada (inclusive os limites), isSaveData e o ambiente sem window/navigator
 * (servidor). O servidor é simulado transpilando o fonte e executando-o com `window` e `navigator` indefinidos,
 * porque o jsdom não deixa esconder esses globais.
 */

type DeviceModule = typeof import("./device");

const originalMatchMedia = window.matchMedia;

function mockMedia(active: string[]) {
  window.matchMedia = jest.fn().mockImplementation((query: string) => ({
    matches: active.includes(query),
    media: query,
    addEventListener() {},
    removeEventListener() {},
  }));
}

function mockNavigator(values: Record<string, unknown>) {
  for (const [key, value] of Object.entries(values))
    Object.defineProperty(navigator, key, { configurable: true, value });
}

function loadOnServer(globals: { window?: unknown; navigator?: unknown }) {
  const source = readFileSync(join(process.cwd(), "lib/device.ts"), "utf8");
  const { outputText } = ts.transpileModule(source, {
    compilerOptions: { module: ts.ModuleKind.CommonJS },
  });
  const loaded = { exports: {} as DeviceModule };
  new Function("module", "exports", "window", "navigator", outputText)(
    loaded,
    loaded.exports,
    globals.window,
    globals.navigator,
  );
  return loaded.exports;
}

beforeEach(() => {
  mockMedia([]);
  mockNavigator({
    hardwareConcurrency: 8,
    deviceMemory: undefined,
    connection: undefined,
  });
});

afterEach(() => {
  window.matchMedia = originalMatchMedia;
});

describe("matches() (through the media helpers)", () => {
  it("path: matchMedia is not available -> every media hint is false", () => {
    // @ts-expect-error simula um navegador sem matchMedia
    window.matchMedia = undefined;

    expect(isCoarsePointer()).toBe(false);
    expect(prefersReducedMotion()).toBe(false);
    expect(isMobileViewport()).toBe(false);
    expect(isLowPowerDevice()).toBe(false);
  });

  it("path: matchMedia answers false for the query -> false", () => {
    expect(isCoarsePointer()).toBe(false);
  });

  it("path: matchMedia answers true only for the asked query -> only that hint is true", () => {
    mockMedia(["(prefers-reduced-motion: reduce)"]);

    expect(prefersReducedMotion()).toBe(true);
    expect(isCoarsePointer()).toBe(false);
    expect(isMobileViewport()).toBe(false);
  });
});

describe("isSaveData()", () => {
  it.each([
    ["connection is missing", undefined],
    ["connection has no saveData", {}],
    ["saveData is false", { saveData: false }],
    ["saveData is a truthy non-boolean", { saveData: "true" }],
  ])("path: %s -> false", (_label, connection) => {
    mockNavigator({ connection });

    expect(isSaveData()).toBe(false);
  });

  it("path: saveData is exactly true -> true", () => {
    mockNavigator({ connection: { saveData: true } });

    expect(isSaveData()).toBe(true);
  });
});

describe("isLowPowerDevice(): limites de cada condição, uma de cada vez", () => {
  it.each([
    ["5 cores", { hardwareConcurrency: 5 }],
    ["8 GB of memory", { hardwareConcurrency: 8, deviceMemory: 8 }],
    ["5 GB of memory", { hardwareConcurrency: 8, deviceMemory: 5 }],
    ["cores reported as text", { hardwareConcurrency: "2" }],
    ["memory reported as text", { deviceMemory: "2" }],
    ["cores reported as null", { hardwareConcurrency: null }],
  ])(
    "path: %s -> full power (just above the limit or not a number)",
    (_label, hints) => {
      mockNavigator(hints);

      expect(isLowPowerDevice()).toBe(false);
    },
  );

  it.each([
    ["exactly 4 cores", { hardwareConcurrency: 4 }],
    ["exactly 4 GB", { deviceMemory: 4 }],
    ["0.5 GB", { deviceMemory: 0.5 }],
    ["1 core", { hardwareConcurrency: 1 }],
  ])("path: %s -> low power", (_label, hints) => {
    mockNavigator(hints);

    expect(isLowPowerDevice()).toBe(true);
  });

  it("path: only the first condition is true (touch) -> low power without reading the rest", () => {
    mockMedia(["(pointer: coarse)"]);
    mockNavigator({ hardwareConcurrency: 16, deviceMemory: 16 });

    expect(isLowPowerDevice()).toBe(true);
  });

  it("path: several conditions true at once -> still just true", () => {
    mockMedia(["(pointer: coarse)", "(prefers-reduced-motion: reduce)"]);
    mockNavigator({
      hardwareConcurrency: 2,
      deviceMemory: 2,
      connection: { saveData: true },
    });

    expect(isLowPowerDevice()).toBe(true);
  });
});

describe("without window and navigator (server)", () => {
  it("path: no window -> media hints are false", () => {
    const device = loadOnServer({ window: undefined, navigator: undefined });

    expect(device.isCoarsePointer()).toBe(false);
    expect(device.prefersReducedMotion()).toBe(false);
    expect(device.isMobileViewport()).toBe(false);
  });

  it("path: no navigator -> save data is off and the device counts as low power", () => {
    const device = loadOnServer({ window: undefined, navigator: undefined });

    expect(device.isSaveData()).toBe(false);
    expect(device.isLowPowerDevice()).toBe(true);
  });

  it("path: a navigator without window (runtime that exposes only navigator) -> hints still read", () => {
    const device = loadOnServer({
      window: undefined,
      navigator: { hardwareConcurrency: 16, connection: { saveData: true } },
    });

    expect(device.isSaveData()).toBe(true);
    expect(device.isLowPowerDevice()).toBe(true);
    const capable = loadOnServer({
      window: undefined,
      navigator: { hardwareConcurrency: 16 },
    });
    expect(capable.isLowPowerDevice()).toBe(false);
  });
});