typescript-type-utils

import type { Equal, ExpectTrue, TupleToUnion } from 'typescript-type-utils'; // Example 1: Basic equality check at compile time type StringIsString = ExpectTrue<Equal<string, string>>; // This type assertion will pass // type StringIsNumber = ExpectTrue<Equal<string, number>>; // Uncommenting this line would cause a compile-time error // Example 2: Using Equal for structural type comparison interface User { id: number; name: string; } type UserAlias = { id: number; name: string; }; type UserTypesAreEqual = ExpectTrue<Equal<User, UserAlias>>; // Asserts structural equality // Example 3: Transforming tuple types to union types type MyTuple = [1, 'hello', true]; type UnionFromTuple = TupleToUnion<MyTuple>; // UnionFromTuple will be 1 | "hello" | true // The types ensure correctness at compile-time. No runtime code is executed. console.log("All type assertions passed at compile time if there are no errors in your IDE/console.");