Property 'active' has no initializer and is not definitely assigned in the constructor.ts(2564)
//inside tsconfig.json file
"angularCompilerOptions": {
// ...
"strictPropertyInitialization": false
// ...
}
Just go to tsconfig.json and set
"strictPropertyInitialization": false
to get rid of the compilation error.
Otherwise you need to initialize all your variables which is a little bit annoying