Private identifiers are only available when targeting ECMAScript 2015 and higher (Angular 9)

Question

I'm upgrading from Angular 8.2 to 9.1 and I'm trying to change private fields to be #fieldName: any as allowed by TS 3.8 instead of private fieldName: any. And I get the compiler error saying

Private identifiers are only available when targeting ECMAScript 2015 and higher.

tsconfig.json:

{
    "compilerOptions": {
        "module": "esnext"
        "target": "es2015",
    }
}

package.json:

"devDependencies": {
   "typescript": "3.8.3"
}

Answer 1

Found this on Reddit, and it was the thing that worked for me:

https://www.reddit.com/r/typescript/comments/1chkjfp/beginner_with_typescript_error_private/

Here are the relevant parts:

"What command are you using to build your project?"

"I am using the command tsc pdfCreation.ts . Though it still seems to compile the file but also gives me errors."

"When you pass a filename on the CLI you're not compiling a project (just a single file) so your tsconfig.json is not used. This is a common mistake (though it's explained in tsc --help).

Instead you should run tsc without filename arguments and use include or files in tsconfig.json to tell TypeScript what to compile."

Worked like a charm!