`device-width` and `device-height` are never measured, though `Dimensions.get("screen")` reports them

从 src/native/conditions/media-query.ts 中的 getMediaFeatureValue 和 src/native/reactivity.ts 中的尺寸处理开始；issue 指出，Dimensions 变更事件包含屏幕尺寸。运行提供的复现测试 src/__tests__/native/device-width.test.tsx，确认失败的 media query。使用 Dimensions.get("screen") 后，设备宽度和高度查询匹配且复现测试通过，即为完成。

Before submitting a new issue

• I tested using the latest version of the library, as the bug might be already fixed.
• I tested using a supported version of react native.
• I checked for possible duplicate issues, with possible answers.

Bug summary

device-width and device-height describe the width and height of the output device's rendering surface. Media Queries 4 deprecates them and still says "User agents must support them as specified" (Appendix A); Chromium 156, Firefox 157 and WebKit 27.2 do, so (min-device-width: 1px) matches everywhere. getMediaFeatureValue (src/native/conditions/media-query.ts) answers width and height from the window, Dimensions.get("window") in src/native/reactivity.ts, and has no arm for these two, so no condition on them ever matches.

All four match in the three engines, and none on main (2421ea7) or on #426 (40bfda2). The Dimensions change event already carries the screen beside the window, so measuring them is an observable over Dimensions.get("screen"); device-aspect-ratio follows once both are measured and #425 compiles ratios.

Library version

main at 2421ea7 (0.0.0-nightly.2421ea7)

Environment info

System:
  OS: Windows 11 10.0.26300
  CPU: "(32) x64 AMD Ryzen 9 9950X3D 16-Core Processor          "
  Memory: 155.26 GB / 255.67 GB
Binaries:
  Node:
    version: 26.12.1
    path: C:\Program Files\nodejs\node.EXE
  Yarn:
    version: 4.9.2
    path: C:\Users\<user>\AppData\Roaming\npm\yarn.CMD
  npm:
    version: 12.2.1
    path: C:\Program Files\nodejs\npm.CMD
  Watchman: Not Found
SDKs:
  Android SDK:
    API Levels:
      - "33"
      - "35"
      - "35"
      - "35"
      - "36"
      - "37"
    Build Tools:
      - 35.0.0
      - 36.0.0
      - 36.1.0
      - 37.0.0
    System Images:
      - android-26 | Google APIs Intel x86_64 Atom
      - android-28 | Google APIs Intel x86_64 Atom
      - android-29 | Google APIs Intel x86_64 Atom
      - android-30 | Google APIs Intel x86_64 Atom
      - android-31 | Google APIs Intel x86_64 Atom
      - android-32 | Google APIs Intel x86_64 Atom
      - android-33 | Google APIs Intel x86_64 Atom
      - android-34 | Google APIs Intel x86_64 Atom
      - android-35 | Google APIs Intel x86_64 Atom
      - android-36.1 | Google Play Intel x86_64 Atom
      - android-36.1 | Pre-Release 16 KB Page Size Google Play Intel x86_64 Atom
      - android-37.0 | Google APIs Intel x86_64 Atom
    Android NDK: Not Found
  Windows SDK: Not Found
IDEs:
  Android Studio: AI-262.9437.185.2621.16467767
  Visual Studio: Not Found
Languages:
  Java:
    version: 17.0.20.1
    path: C:\Program Files\Microsoft\jdk-17.0.20.101-hotspot\bin\javac.EXE
  Ruby: Not Found
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native:
    installed: 0.86.3
    wanted: 0.86.3
  react-native-windows: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: Not found
  newArchEnabled: Not found
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Steps to reproduce

1. Clone the reproducer branch, which is main at 2421ea7 with one file added, src/__tests__/native/device-width.test.tsx, and install:

   git clone --branch repro/515-device-width-unmeasured https://github.com/YevheniiKotyrlo/react-native-css
   cd react-native-css
   yarn install
   

2. Run yarn jest src/__tests__/native/device-width.test.tsx.

src/__tests__/native/device-width.test.tsx:

// device-width and device-height are the screen's (MQ4 Appendix A), which Dimensions.get("screen") reports
import { render, screen } from "@testing-library/react-native";
import { View } from "react-native-css/components/View";
import { registerCSS } from "react-native-css/jest";

test.each([
  ["(device-width)", true],
  ["(min-device-width: 1px)", true],
  ["not (max-device-width: 1px)", true],
  ["(min-device-height: 1px)", true],
])("@media %s matches: %s", (condition, expected) => {
  registerCSS(`
    .child { width: 10px; }
    @media ${condition} { .child { width: 37px; } }
  `);
  render(<View testID="child" className="child" />);
  expect(screen.getByTestId("child").props.style.width === 37).toBe(expected);
});

Expected: (min-device-width: 1px) and (min-device-height: 1px) match, from Dimensions.get("screen").

Actual: no condition on device-width or device-height ever matches.

FAIL src/__tests__/native/device-width.test.tsx
  × @media (device-width) matches: true (19 ms)
  × @media (min-device-width: 1px) matches: true (4 ms)
  × @media not (max-device-width: 1px) matches: true (2 ms)
  × @media (min-device-height: 1px) matches: true (1 ms)
  ● @media (device-width) matches: true
    expect(received).toBe(expected) // Object.is equality
    Expected: true
    Received: false
      15 |   `);
      16 |   render(<View testID="child" className="child" />);
    > 17 |   expect(screen.getByTestId("child").props.style.width === 37).toBe(expected);
         |                                                                ^
      18 | });
      19 |
      at toBe (src/__tests__/native/device-width.test.tsx:17:64)
  ● @media (min-device-width: 1px) matches: true
    expect(received).toBe(expected) // Object.is equality
    Expected: true
    Received: false
      15 |   `);
      16 |   render(<View testID="child" className="child" />);
    > 17 |   expect(screen.getByTestId("child").props.style.width === 37).toBe(expected);
         |                                                                ^
      18 | });
      19 |
      at toBe (src/__tests__/native/device-width.test.tsx:17:64)
  ● @media not (max-device-width: 1px) matches: true
    expect(received).toBe(expected) // Object.is equality
    Expected: true
    Received: false
      15 |   `);
      16 |   render(<View testID="child" className="child" />);
    > 17 |   expect(screen.getByTestId("child").props.style.width === 37).toBe(expected);
         |                                                                ^
      18 | });
      19 |
      at toBe (src/__tests__/native/device-width.test.tsx:17:64)
  ● @media (min-device-height: 1px) matches: true
    expect(received).toBe(expected) // Object.is equality
    Expected: true
    Received: false
      15 |   `);
      16 |   render(<View testID="child" className="child" />);
    > 17 |   expect(screen.getByTestId("child").props.style.width === 37).toBe(expected);
         |                                                                ^
      18 | });
      19 |
      at toBe (src/__tests__/native/device-width.test.tsx:17:64)
Test Suites: 1 failed, 1 total
Tests:       4 failed, 4 total
Snapshots:   0 total
Time:        1.053 s, estimated 2 s
Ran all test suites matching /src\\__tests__\\native\\device-width.test.tsx/i.

Reproducible example repository

https://github.com/YevheniiKotyrlo/react-native-css/tree/repro/515-device-width-unmeasured