Angular CLI - Typescript抛出:无法读取未定义的属性'length‘

Question

我在angular 4项目中使用ng服务器运行，得到错误。

Cannot read property 'length' of undefined

但是我的项目中没有任何属性长度..

完整的错误

    Your global Angular CLI version (1.2.1) is greater than your local
version (1.1.3). The local Angular CLI version is used.

To disable this warning use "ng set --global warnings.versionMismatch=false".
Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
    at createSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:15457:109)
    at parseSourceFileWorker (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:15389:26)
    at Object.parseSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:15338:26)
    at Object.createSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:15192:29)
    at VirtualFileStats.getSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\@ngtools\webpack\src\compiler_host.js:66:35)
    at WebpackCompilerHost.getSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\@ngtools\webpack\src\compiler_host.js:213:38)
    at findSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67909:29)
    at processImportedModules (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:68056:25)
    at findSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67937:17)
    at processImportedModules (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:68056:25)
    at findSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67937:17)
    at processSourceFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67840:27)
    at processRootFile (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67728:13)
    at E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67018:60
    at Object.forEach (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:1449:30)
    at Object.createProgram (E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master\node_modules\typescript\lib\typescript.js:67018:16)
PS E:\פרוייקטים\פרוייקטים קיץ\Angular 4\Youtube Channel Angular Firebase\full project of the instructor github\angular-firestarter-master>

package.json

{
  "name": "firestarter",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^4.2.4",
    "@angular/common": "^4.2.4",
    "@angular/compiler": "^4.2.4",
    "@angular/core": "^4.2.4",
    "@angular/forms": "^4.2.4",
    "@angular/http": "^4.2.4",
    "@angular/platform-browser": "^4.2.4",
    "@angular/platform-browser-dynamic": "^4.2.4",
    "@angular/platform-server": "^4.2.4",
    "@angular/router": "^4.2.4",
    "@types/lodash": "^4.14.67",
    "angularfire2": "^4.0.0-rc.1",
    "core-js": "^2.4.1",
    "firebase": "^4.1.3",
    "lodash": "^4.17.4",
    "rxjs": "^5.4.1",
    "zone.js": "^0.8.12"
  },
  "devDependencies": {
    "@angular/cli": "^1.1.3",
    "@angular/compiler-cli": "^4.2.4",
    "@types/jasmine": "2.5.53",
    "@types/node": "~8.0.4",
    "codelyzer": "~3.1.1",
    "jasmine-core": "~2.6.4",
    "jasmine-spec-reporter": "~4.1.1",
    "karma": "~1.7.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.3.0",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.1.0",
    "tslint": "~5.4.3",
    "typescript": "=2.3.4"
  }
}

Answer 1

您可能缺少typescript尝试处理的一个或多个文件。要找出丢失的文件，只需添加

console.log(fileName)；

在node/typescript/lib/typecript.js文件中的createSourceFile函数的开始处。

Answer 2

我的错误是由创建一个小组件时的c&p错误引起的。我忘了更改组件的模板和样式的路径。

Answer 3

最有可能的情况是，您已经以需要重新启动CLI的方式对模块进行了更改。

在从模块中删除组件后，运行ng serve时也出现了同样的错误。通过重新启动该进程并重新运行ng serve，错误消失了。