The Tailwind test harness's `render` throws on an element whose child is text

从src/__tests__/vendor/tailwind/_tailwind.tsx开始，跟踪getClassNames如何遍历component.props.children；复现用例位于src/__tests__/vendor/tailwind/harness-text-child.test.tsx，使用yarn jest src/__tests__/vendor/tailwind/harness-text-child.test.tsx运行。确保在编译元素自身的 className 时，文本子节点的情况能够得到处理，并检查debug: "verbose"是否也会进入详细规则日志。

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

render in src/__tests__/vendor/tailwind/_tailwind.tsx collects the class names to compile with getClassNames, which reads component.props.children of every child it walks, so a text child, which has no props, throws before anything compiles.

The text child fails, Rejected to value: [TypeError: Cannot read properties of undefined (reading 'children')]; the false child passes.

In the same helper, registerCSS(output, { debug: Boolean(debug) }) turns debug: "verbose" into true, so the verbose rule log NativewindRenderOptions offers never runs.

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__/vendor/tailwind/harness-text-child.test.tsx, and install:

   git clone --branch repro/545-tailwind-test-harness https://github.com/YevheniiKotyrlo/react-native-css
   cd react-native-css
   yarn install
   

2. Run yarn jest src/__tests__/vendor/tailwind/harness-text-child.test.tsx.

src/__tests__/vendor/tailwind/harness-text-child.test.tsx:

import { Text } from "react-native-css/components/Text";
import { View } from "react-native-css/components/View";

import { render } from "./_tailwind";

test("render takes an element whose child is text", async () => {
  await expect(render(<Text className="text-red-500">hello</Text>)).resolves.toBeDefined();
});

test("render takes an element with a false child", async () => {
  await expect(render(<View className="p-1">{false}</View>)).resolves.toBeDefined();
});

Expected: render skips a text child and compiles the element's own className.

Actual: it throws before anything compiles, reading children of the text child.

FAIL src/__tests__/vendor/tailwind/harness-text-child.test.tsx
  × render takes an element whose child is text (3 ms)
  √ render takes an element with a false child (55 ms)
  ● render takes an element whose child is text
    expect(received).resolves.toBeDefined()
    Received promise rejected instead of resolved
    Rejected to value: [TypeError: Cannot read properties of undefined (reading 'children')]
       5 |
       6 | test("render takes an element whose child is text", async () => {
    >  7 |   await expect(render(<Text className="text-red-500">hello</Text>)).resolves.toBeDefined();
         |         ^
       8 | });
       9 |
      10 | test("render takes an element with a false child", async () => {
      at expect (node_modules/expect/build/index.js:113:15)
      at Object.expect (src/__tests__/vendor/tailwind/harness-text-child.test.tsx:7:9)
      at asyncGeneratorStep (node_modules/@babel/runtime/helpers/asyncToGenerator.js:3:17)
      at _next (node_modules/@babel/runtime/helpers/asyncToGenerator.js:17:9)
      at node_modules/@babel/runtime/helpers/asyncToGenerator.js:22:7
      at Object.<anonymous> (node_modules/@babel/runtime/helpers/asyncToGenerator.js:14:12)
Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 passed, 2 total
Snapshots:   0 total
Time:        1.342 s, estimated 2 s
Ran all test suites matching /src\\__tests__\\vendor\\tailwind\\harness-text-child.test.tsx/i.

Reproducible example repository

https://github.com/YevheniiKotyrlo/react-native-css/tree/repro/545-tailwind-test-harness