How to check typeof / isntanceof for SafeHtml in typescript?-CodePudding

I have a variable of type string or SafeHtml and I have a method which checks, if the param is of type string or SafeHtml. Based upon the type of the param I want to do different stuff. I tried instanceof and typeof but both seem not to be working for SafeHtml. How can i check, if a variable is of type SafeHtml?

public isSafeHtml(value: string | SafeHtml) {
    if (typeof value === 'string' || value instanceof String) {
        // ..stuff for case string
    }
    if (typeof value === 'SafeHtml' // not working
        || value instanceof SafeHtml) // not working
    {
        // ..stuff for case SafeHtml
    }
}

typeof seems to be working only for basic types, such as 'string' | 'number' | ...

instanceof SafeHtml isn't working because 'SafeHtml' only refers to a type, but is being used as a value here?

CodePudding user response：

SafeHtml is an interface for a type, since your union is a simple string | SafeHtml you just need to check for the string:

public isSafeHtml(value: string | SafeHtml) {
  if (typeof value === 'string') {
    // ..stuff for case string
    return;
  }

 // ..stuff for case SafeHtml
}