error TS5107: Option 'target=ES5' is deprecated and will stop functioning in TypeScript 7.0. Specify compilerOption '"ignoreDeprecations": "6.0"' to silence this error.


!!! error TS5107: Option 'target=ES5' is deprecated and will stop functioning in TypeScript 7.0. Specify compilerOption '"ignoreDeprecations": "6.0"' to silence this error.
==== classStaticPropertyTypeGuard.ts (0 errors) ====
    // Repro from #8923
    
    class A {
        private static _a: string | undefined;
    
        public get a(): string {
            if (A._a) {
                return A._a; // is possibly null or undefined.
            }
            return A._a = 'helloworld';
        }
    }