🐨 Adds result types - Result, Error & Ok

app/src/lib/utilities/result.ts

@@ -1,22 +0,0 @@
-export class Result<T, E> {
-    private constructor(
-        private readonly isSuccess: boolean, 
-        public readonly value?: T, 
-        public readonly error?: E) {}
-  
-    public static ok<T>(value: T): Result<T, null> {
-      return new Result<T, null>(true, value);
-    }
-  
-    public static fail<E>(error: E): Result<null, E> {
-      return new Result<null, E>(false, null, error);
-    }
-  
-    public isOk(): this is Result<T, null> {
-      return this.isSuccess;
-    }
-  
-    public isErr(): this is Result<null, E> {
-      return !this.isSuccess;
-    }
-}

app/src/lib/utilities/result/err.ts

@@ -0,0 +1,36 @@
+export class Err<T> {
+  #inner: T
+
+  constructor(inner: T) {
+    this.#inner = inner
+  }
+
+  get inner(): T {
+    return this.#inner
+  }
+
+  /**
+   * Type guard for `Ok`
+   * @returns `true` if `Ok`; `false` if `Err`
+   */
+  isOk(): false {
+    return false
+  }
+
+  /**
+   * Type guard for `Err`
+   * @returns `true` if `Err`; `false` if `Ok`
+   */
+  isErr(): this is Err<T> {
+    return true
+  }
+
+  /**
+   * Create an `Err`
+   * @param inner
+   * @returns `Err(inner)`
+   */
+  static new<E>(inner: E): Err<E> {
+    return new Err<E>(inner)
+  }
+}

app/src/lib/utilities/result/index.ts

@@ -0,0 +1,3 @@
+export * from './err'
+export * from './ok'
+export * from './result'

app/src/lib/utilities/result/ok.ts

@@ -0,0 +1,36 @@
+export class Ok<T> {
+  #inner: T
+
+  constructor(inner: T) {
+    this.#inner = inner
+  }
+
+  get inner(): T {
+    return this.#inner
+  }
+
+  /**
+   * Type guard for `Ok`
+   * @returns `true` if `Ok`; `false` if `Err`
+   */
+  isOk(): this is Ok<T> {
+    return true
+  }
+
+  /**
+   * Type guard for `Err`
+   * @returns `true` if `Err`; `false` if `Ok`
+   */
+  isErr(): false {
+    return false
+  }
+
+  /**
+   * Create an `Ok`
+   * @param inner
+   * @returns `Ok(inner)`
+   */
+  static new<T>(inner: T): Ok<T> {
+    return new Ok<T>(inner)
+  }
+}

app/src/lib/utilities/result/result.ts

@@ -0,0 +1,20 @@
+import { Err } from './err'
+import { Ok } from './ok'
+
+export type Result<T = unknown, E = unknown> = Ok<T> | Err<E>
+
+export namespace Result {
+  /**
+   * @returns `Ok<T>`
+   */
+  export function ok<T = unknown>(value: T) {
+    return Ok.new(value)
+  }
+
+  /**
+   * @returns `Err<E>`
+   */
+  export function err<E = unknown>(error: E) {
+    return Err.new(error)
+  }
+}