Pull request overview

This pull request refactors the Result<T, E> type from a single class with static factory methods to a discriminated union of Success<T> and Failure<E> classes. This improves TypeScript's type inference, allowing the compiler to correctly narrow types in conditional branches when checking isSuccess() or isFailure().

Changes:

• Replaced the single Result class with two separate classes (Success and Failure) that form a discriminated union
• Updated all call sites from Result.success() and Result.failure() to use new Success() and new Failure() constructors
• Updated tests to reflect the new API

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

src/util.test.ts:567

• The test description still references "Result.success" but the implementation now uses "new Success()". Consider updating the test description to match the new API, for example: "Success creates a success result".

test("Result.success creates a success result", (t) => {

LGTM with one minor comment. Also, was there a particular advantage you found to the class-based approach over something like:

type Success<T> = { isSuccess: true, value: T };
type Failure<E> = { isSuccess: false, value: E };
type Result<T, E> = Success<T> | Failure<E>;