Effect CommunityEC
Effect Community•3y ago•
45 replies
Projitect

Defensive Typing for Third-Party Code in TypeScript

Hi all! In my project, I'm going to be importing some third-party code that should evaluate to an Effect<SomeKnownShape, unknown, unknown>, and want to be defensive about types.

I'm thinking about writing a function that looks like this, but I'm not sure of the best way to do that:
import * as Effect from "@effect/io/Effect";

const safeEffect = (
  thirdPartyEffect: unknown
): Effect.Effect<unknown, unknown, unknown> => {
  if (thirdPartyEffect === null || thirdPartyEffect === undefined) {
    return Effect.fail(undefined /* Some error message */);
  }

  if (typeof thirdPartyEffect !== "function") {
    return Effect.fail(undefined /* Some error message */);
  }

  // Is there any way to validate R?
  const returnValue = thirdPartyEffect();
  // Fail if returnValue is not an Either<unknown, unknown>

  // Note that I don't know even at runtime what the E and A types are, so there's no way to validate those

  // Now that returnValue is validated, return that
};


Is this just a silly effort?

Is there something in @effect/schema that could help with this (it seems those are more geared towards validating primitives and objects)?

I'm lost trying to figure out a way to validate such code
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