Visual Studio中的Angular 6组件声明编译器错误

Question

I have just upgraded a project from Angular 4 to Angular 6. But I am now getting a compiler error in my Component declarations in Visual Studio. So the following basic declaration is underlined in red:

@Component({ 
    template: ''
}) 

And on rollover shows the error:

Argument of type '{ template: string }' is not assignable to parameter of type 'Component' Property 'true' is missing in type '{ template: string }'

It doesn't matter how complicated this declaration is, whether is has a selector, template url or styles or whatever, it doesn't matter, the error is still there, just longer.

Now this has zero effect on the app compiling and running, it just shows up as an error in the editor. So it must be a typescript config issue when moving from Angular 4 to Angular 6. When loading the Angular 4 project in Visual Studio, the error does not appear.

I am using Visual Studio 2015, the latest version of the Angular CLI (6.2.3), Typescript 2.8.3 and TsLint 5.11.0.

My tsconfig for the project is as follows:

{
  "compileOnSave": false,
  "compilerOptions": {
    "outDir": "./dist/out-tsc",
    "baseUrl": "src",
    "sourceMap": true,
    "declaration": false,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "preserveWhitespaces": "off",
    "strictPropertyInitialization": false,
    "target": "es5",
    "typeRoots": [
      "node_modules/@types"
    ],
    "lib": [
      "es2016",
      "dom"
    ]
  }
}

Any help would be much appreciated.

Cheers John

Answer 1

Angular 6 has @angular/language-service configured in package.json

This does checks in your IDE that were not done in Angular 4.

Because it is very new I think it can get it wrong sometimes, so that might be your problem.

Docs are here:

https://angular.io/guide/language-service

I don't use Visual Studio so never seen this but had similar kinds of issue in WebStorm.

Generally, however the language service is good at picking up problems so best keep it enabled. Maybe somehow try and either fix or ignore the error you are getting for now.