React Native在iOS模拟器上运行加载文件时出现 Failed to load bundle(:8081/index.bundle?platform=ios&dev=true&minify=false) with error:(/Users/dp/Documents/React Native/SHRControl/App.js: Cannot read property 'bindings' of null (null))错误，必现！

{  "name": "SHRControl",  "version": "0.0.1",  "private": true,  "scripts": {    "start": "node node_modules/react-native/local-cli/cli.js start",    "test": "jest"  },  "dependencies": {    "eslint": "^4.19.1",    "lodash": "^4.17.10",    "react": "^16.4.1",    "react-native": "^0.56.0",    "react-native-accordion": "^1.0.1",    "react-native-animatable": "^1.3.0",    "react-native-collapsible": "^0.11.3",    "react-native-elements": "^0.19.1",    "react-native-vector-icons": "^4.6.0",    "react-navigation": "^1.5.12",    "react-redux": "^5.0.7",    "redux": "^3.7.2",    "redux-logger": "^3.0.6",    "redux-persist": "^5.10.0",    "redux-saga": "^0.16.0",    "redux-thunk": "^2.3.0"  },  "devDependencies": {    "babel-jest": "22.4.3",    "babel-preset-react-native": "4.0.0",    "jest": "22.4.3",    "react-test-renderer": "16.3.1"  },  "jest": {    "preset": "react-native"  }}

通过网上查找，找到了出现同样问题的相关连接：

npm install --save babel-preset-react-native@5

重新安装了babel-preset-react-native的5.0.2版本，重新运行，结果还是下面这样：

error: bundling failed: TypeError: Cannot read property 'bindings' of null    at Scope.moveBindingTo (/Users/dp/Documents/React Native/SHRControl/node_modules/@babel/traverse/lib/scope/index.js:978:12)    at BlockScoping.updateScopeInfo (/Users/dp/Documents/React Native/SHRControl/node_modules/babel-plugin-transform-es2015-block-scoping/lib/index.js:364:17)    at BlockScoping.run (/Users/dp/Documents/React Native/SHRControl/node_modules/babel-plugin-transform-es2015-block-scoping/lib/index.js:330:12)    at PluginPass.BlockStatementSwitchStatementProgram (/Users/dp/Documents/React Native/SHRControl/node_modules/babel-plugin-transform-es2015-block-scoping/lib/index.js:70:24)    at newFn (/Users/dp/Documents/React Native/SHRControl/node_modules/@babel/traverse/lib/visitors.js:237:21)    at NodePath._call (/Users/dp/Documents/React Native/SHRControl/node_modules/@babel/traverse/lib/path/context.js:65:20)    at NodePath.call (/Users/dp/Documents/React Native/SHRControl/node_modules/@babel/traverse/lib/path/context.js:40:17)    at NodePath.visit (/Users/dp/Documents/React Native/SHRControl/node_modules/@babel/traverse/lib/path/context.js:100:12)    at TraversalContext.visitQueue (/Users/dp/Documents/React Native/SHRControl/node_modules/@babel/traverse/lib/context.js:142:16) BUNDLE  [ios, dev] ../../index.js ░░░░░░░░░░░░░░░░ 0.0% (0/1), failed.

没办法，只好在试下面，删除整个模块，重新安装：

rm -rf node_modules && npm install

然后：

1. 重新运行，还是不行；  2. Xcode上点击`Product => Clean`清除后再运行还是不行；  3. 第2步再加上删掉模拟器上的APP，再运行还是不行。

最后想到自己再在终端用react-native init RNtest新建一个项目，运行成功后查看它的package.json文件，检查依赖模块devDependencies发现不一样，然后果断把出问题的项目依赖"devDependencies"换成：

{    "babel-jest": "23.4.0",    "babel-preset-react-native": "5.0.2",    "jest": "23.4.1",    "react-test-renderer": "16.4.1"  }

然后再通过上面的三步骤进行尝试，还是红屏，差点崩溃?。

最后放大超：点击Xcode的Product再按键盘上的【option】键，然后出现Clean Build Folder并点击，再弹框点击Clean，清理结束后，并且删掉模拟器上旧的APP，运行，通过了。

总结

a. babel-preset-react-native更新到最新，例如：

{    "babel-jest": "23.4.0",    "babel-preset-react-native": "5.0.2",    "jest": "23.4.1",    "react-test-renderer": "16.4.1"  }

b. 删除React Native所有模块重新安装

rm -rf node_modules && npm install

c. 点击Xcode的Product再按键盘上的【option】键，然后出现Clean Build Folder并点击，再弹框点击Clean，清理结束后，并且删掉模拟器上旧的APP。