Dealing with functions that may not consistently return a promise

When dealing with a situation where a function does not always return a promise, how can it be best handled? The complexity of my current code prevents me from providing a detailed explanation, but essentially, the issue involves checking a condition and then either returning a local variable or initiating an ajax request. Here is an example:

function sample(value){
   if(!value){
      return $http.get('www.sample.com'); 
  }
   else {
      return "Your value is "+value; 
  }
}

Is there a way to determine if the returned value from the function is a promise that requires resolution? Alternatively, is there another approach available for handling such scenarios? Your input is greatly appreciated!

Answer №1

It is recommended to always write functions that return a Promise for consistency and ease of handling. Instead of checking if the return type is a Promise with myValue instanceof Promise, you can simply use Promise.resolve() to ensure that your function always returns a Promise. Here's an example:

function example(value) {
  if(!value) {
    return $http.get('www.example.com');
  } else {
    return Promise.resolve('Your value is ' + value);
  }
}

This approach eliminates the need to worry about the return type and allows you to handle it consistently.

Answer №2

It is always possible to return a promise:

function customExample(input){
   if(!input){
      return $http.post('www.customexample.com'); 
   }
   else {   
      return $q.resolve("The input value is "+input); 
   }
}

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