升级到Babel 7:无法读取null的属性"绑定"

Question

我刚刚通过运行以下命令升级到Babel 7(从6开始):

npm remove babel-cli
npm install --save-dev @babel/cli @babel/core @babel/preset-env

这是我的.babelrc档案:

{ "presets": ["env"] }

然后我跑了:

babel js/src --out-dir js/dist

它导致:

TypeError: Cannot read property 'bindings' of null
    at Scope.moveBindingTo (/xyz/node_modules/@babel/traverse/lib/scope/index.js:867:13)
    at BlockScoping.updateScopeInfo (/xyz/node_modules/babel-plugin-transform-es2015-block-scoping/lib/index.js:364:17)
    at BlockScoping.run (/xyz/node_modules/babel-plugin-transform-es2015-block-scoping/lib/index.js:330:12)
    at PluginPass.BlockStatementSwitchStatementProgram (/xyz/node_modules/babel-plugin-transform-es2015-block-scoping/lib/index.js:70:24)
    at newFn (/xyz/node_modules/@babel/traverse/lib/visitors.js:193:21)
    at NodePath._call (/xyz/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/xyz/node_modules/@babel/traverse/lib/path/context.js:40:17)
    at NodePath.visit (/xyz/node_modules/@babel/traverse/lib/path/context.js:88:12)
    at TraversalContext.visitQueue (/xyz/node_modules/@babel/traverse/lib/context.js:118:16)
    at TraversalContext.visitSingle (/xyz/node_modules/@babel/traverse/lib/context.js:90:19)

我做错了什么？

Answer 1

在您的.babelrc文件中,更改

{ "presets": ["env"] } 

至

{ "presets": ["@babel/preset-env"] }

(如果还没有,请安装该软件包).

在您.babelrc仍在引用该程序包babel-preset-env(适用于6.x)时,您需要引用@babel/preset-env(而不是7.x).

https://github.com/babel/babel/issues/6186#issuecomment-366556833