TypeScript-尝试调用超级setter / getter时出错（仅通过prod任务重现）

Question

When I try call super getter or super setter when overriding properties? I get an error: TS2340: Only public and protected methods of the base class are accessible via the 'super' keyword.

This error I get only when execute 'ng build --configuration=production --stats-json'

This error appeared after the I update Angular from v7.2.11 to v8.0.3 (TypeScrypt from v3.1.6 to v3.4.5).

With Angular v7.2.11 and TypeScrypt v3.1.6 there is no such error. I don't use targeting to es5. I tried to target es2015, es2016, es2017, but I get the same error in each case.

Code example

export abstract class ChildComponent extends ParentComponent {
    get selected(): boolean {
        return super.selected;
    }
    set selected(selected: boolean) {
        super.selected = selected;
    }
}
export abstract class ParentComponent {
    public get selected(): boolean {
        return this._selected;
    }
    public set selected(value: boolean) {
        this._selected = value;
    }
}

My tsconfig:

{
        "compileOnSave": false,
        "compilerOptions": {
                "downlevelIteration": true,
                "outDir": "./dist",
                "baseUrl": ".",
                "sourceMap": true,
                "declaration": false,
                "moduleResolution": "node",
                "module": "esnext",
                "emitDecoratorMetadata": true,
                "experimentalDecorators": true,
                "noEmitHelpers": true,
                "importHelpers": true,
                "esModuleInterop": true,
                "target": "es2015",
                "typeRoots": [
                       "node_modules/@types"
                ],
                "lib": [
                       "es2017",
                       "dom"
                ],
                "paths": {
                   ...
                }
        },
        "exclude": [
        ...
       ]
}

I expected my code to start working after I switched to “target”: “es2015”, but it didn't. Maybe there is any errors in my config?

I also do not use the arrow functions, so as far as I understand, my problem is not related to the context.

Answer 1

In Angular CLI version 8 and higher, differential loading is enabled by default for the ng build command . As a result, this produces two builds, and differential loading is enabled. If you ignore browsers without ES2015 support, a single build is produced.

You can do this by setting .browserlistrc to ignore or include browsers that you needed. Otherwise you can add the "browserslist" field to your package.json .