I'm currently working on a function that has the capability to call multiple APIs while providing strong typing for each parameter: api - which represents the name of the API, route - the specific route within the 'api', and params - a JSON object containing the required parameters for the chosen API and route.
To better illustrate what I have in mind, I've created an example using the TS Playground here.
The code snippet is as follows:
type APINames = "google" | "yahoo";
type Routes<A extends APINames> = {
google: "endpoint1" | "endpoint2";
yahoo: "endpoint3";
}[A];
type RouteParams<A extends APINames, R extends Routes<A>> = {
google: {
endpoint1: {
name: string;
};
endpoint2: {
otherName: string;
};
};
yahoo: {
endpoint3: {
otherOtherName: string;
};
};
}[A][R];
const execute = <A extends APINames, R extends Routes<A>>(api: A, route: R, params: RouteParams<A, R>) => {
// ... code
}
execute('google', 'endpoint1', {
name: 'George Washington'
});
There seems to be a type error arising from my RouteParams type. The issue lies in the fact that, although [A] serves as a valid first index, [R] does not qualify as a legitimate second index due to the fact that R now holds the type
'endpoint1' | 'endpoint2' | 'endpoint3'RouteParams object. Despite this setback, the provided code does offer useful typing assistance when utilizing the execute function. It's imperative for me to resolve the TypeScript error pertaining to RouteParams. I suspect that there might be a utility type out there capable of addressing this issue, and I am also open to exploring solutions involving completely different structures.
Ultimately, the main objective is to create a function that accepts three arguments: the first being an API name selected from a union type, the second representing a route derived from a union type associated with the specified API, and the third consisting of a JSON parameters object linked to the combination of the API name and route.