【发布时间】：2017-01-18 08:39:28
【问题描述】：
我正在尝试使用 TypeScript 构建 Redux 中间件。这个函数
import { Middleware } from "redux"
function createMiddleware() {
return ({ dispatch, getState }) => next => action => {
if (Math.random() > 0.5) {
return next(action)
}
return next(action)
}
}
export const middleware: Middleware = createMiddleware()
产生一个 TypeScript 错误：
Typescript error: Cannot read property 'exports' of undefined
虽然当我删除 if 块时编译器没有抱怨。
我的tsconfig.json
{
"compilerOptions": {
"module": "commonjs",
"target": "ES5",
"noImplicitAny": false,
"skipLibCheck": true,
"noUnusedLocals": true,
"noUnusedParameters": true,
"jsx": "react",
"lib": ["dom", "es2015", "es2016"],
"baseUrl": "../src",
"exclude": [
"node_modules"
]
}
}
编辑来自浏览器控制台的堆栈跟踪
Uncaught Error: Module build failed: TypeError: Cannot read property 'exports' of undefined
at resolveName (..\node_modules\typescript\lib\typescript.js:24948:70)
at getResolvedSymbol (..\node_modules\typescript\lib\typescript.js:32549:67)
at checkIdentifier (..\node_modules\typescript\lib\typescript.js:33700:26)
at checkExpressionWorker (..\node_modules\typescript\lib\typescript.js:38185:28)
at checkExpression (..\node_modules\typescript\lib\typescript.js:38165:42)
at checkNonNullExpression (..\node_modules\typescript\lib\typescript.js:35540:24)
at checkPropertyAccessExpressionOrQualifiedName (..\node_modules\typescript\lib\typescript.js:35587:24)
at checkPropertyAccessExpression (..\node_modules\typescript\lib\typescript.js:35554:20)
at checkExpressionWorker (..\node_modules\typescript\lib\typescript.js:38208:28)
at checkExpression (..\node_modules\typescript\lib\typescript.js:38165:42)
at checkNonNullExpression (..\node_modules\typescript\lib\typescript.js:35540:24)
at resolveCallExpression (..\node_modules\typescript\lib\typescript.js:36556:28)
at resolveSignature (..\node_modules\typescript\lib\typescript.js:36786:28)
at getResolvedSignature (..\node_modules\typescript\lib\typescript.js:36809:26)
at checkCallExpression (..\node_modules\typescript\lib\typescript.js:36836:29)
at checkExpressionWorker (..\node_modules\typescript\lib\typescript.js:38213:28)
at resolveName (..\node_modules\typescript\lib\typescript.js:24948:70)
at getResolvedSymbol (..\node_modules\typescript\lib\typescript.js:32549:67)
at checkIdentifier (..\node_modules\typescript\lib\typescript.js:33700:26)
at checkExpressionWorker (..\node_modules\typescript\lib\typescript.js:38185:28)
at checkExpression (..\node_modules\typescript\lib\typescript.js:38165:42)
at checkNonNullExpression (..\node_modules\typescript\lib\typescript.js:35540:24)
at checkPropertyAccessExpressionOrQualifiedName (..\node_modules\typescript\lib\typescript.js:35587:24)
at checkPropertyAccessExpression (..\node_modules\typescript\lib\typescript.js:35554:20)
at checkExpressionWorker (..\node_modules\typescript\lib\typescript.js:38208:28)
at checkExpression (..\node_modules\typescript\lib\typescript.js:38165:42)
at checkNonNullExpression (..\node_modules\typescript\lib\typescript.js:35540:24)
at resolveCallExpression (..\node_modules\typescript\lib\typescript.js:36556:28)
at resolveSignature (..\node_modules\typescript\lib\typescript.js:36786:28)
at getResolvedSignature (..\node_modules\typescript\lib\typescript.js:36809:26)
at checkCallExpression (..\node_modules\typescript\lib\typescript.js:36836:29)
at checkExpressionWorker (..\node_modules\typescript\lib\typescript.js:38213:28)
at Object../src/store/middleware.ts (http://localhost:8080/static/js/main.js:69038:7)
at __webpack_require__ (http://localhost:8080/static/js/main.js:660:30)
【问题讨论】：
-
你是在 nodejs 中运行代码还是在浏览器中运行代码？ Afaik
commonjs是 nodejs 模块系统。 -
在浏览器中。我将 Webpack 2.2.0-rc 与 awesome-typescript-loader 3.0.0-beta 一起使用（与 2.1.4 和 ts-loader 相同的错误）。由于 react-router 错误，我无法使用设置
"module": "ES6"。 -
你知道 webpack 和/或 awesome-ts-loader 是否真的支持在浏览器中加载 commonjs 模块吗？因为'exports'是一个必须由模块加载器提供的对象，根据你得到的错误，你得到的对象显然是错误的。
-
是的，webpack 支持 commonjs：webpack.js.org/concepts/modules 错误似乎来自 TypeScript 编译器
-
添加了来自浏览器控制台的堆栈跟踪。你是对的，从外观上看，它可能与 Webpack 2 有关。
标签： typescript compiler-errors webpack react-redux typescript2.0