I have a situation where I need to call an async method on the result of an async method.
class Parent {
constructor(private child: Child) { }
private
Is there a way to design my API better so that users won't need the double await? Even if it means changing the structure of my example drastically.
You must not make getResult
asynchronous, it needs to return a Result
instance right away so that further methods can be called on it. Your example is a bit weird since getChild
doesn't really need to be asynchronous at all. But lets assume it is, and does some important.
You then could write
class Parent {
private async getChild(): Promise {
… // whatever
}
getResult(): Result {
return new Result(this.getChild())
}
}
class Result {
constructor(p: Child) {
this.promise = p;
}
async getText(): Promise {
return (await this.promise).getText();
}
}
Now you can call parent.getResult().getText()
directly. Basically, Result
acts as a proxy wrapper around the Child
class that does both the awaits. Maybe in your actual architecture you can even avoid the this.promise
and do the child and text accesses in one step.
However, usually this is not worth it. Just let your caller await
each step.