angular - 即使 tsc 版本足够高，带有 bang 运算符的 Typescript 文件也不会构建

Question

我有一个带有这个文件的 angular 4 项目

class DemoClass {
    description!: string;
}

如果我用

构建它

ng build

从我得到的项目根

ERROR in src/app/client/medisoft-client.ts(3,16): error TS1005: '=' expected. src/app/client/medisoft-client.ts(3,17): error TS1109: Expression expected.

删除 bang 运算符可以解决这个问题，所以这肯定是问题所在。错误似乎是类型脚本的版本不够高但是如果我运行

tsc --version

我明白了

Version 3.3.4000

足以支持 bang 运算符。如果我转到包含该文件的目录并只转换该文件，即移动，即

tsc --out test.js test.ts

然后它构建正常，我得到了 js 输出

所以看起来 angular 使用的是旧版本的 typescript ，但我不知道现在该去哪里解决这个问题

Package.json文件是

{   "name": "project-name",   "version": "0.0.0",   "license": "MIT",  "scripts": {
    "ng": "ng",
    "start": "ng build --base-href /Angular --deploy-url /Angular/",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"   },   "private": true,   "dependencies": {
    "@angular/animations": "^5.2.0",
    "@angular/common": "^5.2.0",
    "@angular/compiler": "^5.2.0",
    "@angular/core": "^5.2.0",
    "@angular/forms": "^5.2.0",
    "@angular/http": "^5.2.0",
    "@angular/platform-browser": "^5.2.0",
    "@angular/platform-browser-dynamic": "^5.2.0",
    "@angular/router": "^5.2.0",
    "core-js": "^2.4.1",
    "rxjs": "^5.5.6",
    "zone.js": "^0.8.19"   },   "devDependencies": {
    "@angular/cli": "1.6.5",
    "@angular/compiler-cli": "^5.2.0",
    "@angular/language-service": "^5.2.0",
    "@types/jasmine": "~2.8.3",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "^4.0.1",
    "jasmine-core": "~2.8.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~2.0.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~4.1.0",
    "tslint": "~5.9.1",
    "typescript": "^2.9.2"   } }

Answer 1

您的 Angular 项目 typescript 版本低于您的全局版本。所以你需要像下面这样在你的 Angular 项目中安装更新版本

npm install typescript@3.3.4000 --save-dev

希望这会有所帮助!