rename to core

core/shared/result/Result.ts

@@ -0,0 +1,78 @@
+export class Result<T, E = Error> {
+  private constructor(
+    private readonly _value?: T,
+    private readonly _error?: E,
+    private readonly _isSuccess: boolean = true
+  ) {}
+
+  static ok<T, E = Error>(value: T): Result<T, E> {
+    return new Result<T, E>(value, undefined, true);
+  }
+
+  static err<T, E = Error>(error: E): Result<T, E> {
+    return new Result<T, E>(undefined, error, false);
+  }
+
+  isOk(): boolean {
+    return this._isSuccess;
+  }
+
+  isErr(): boolean {
+    return !this._isSuccess;
+  }
+
+  unwrap(): T {
+    if (!this._isSuccess) {
+      throw new Error('Called unwrap on an error result');
+    }
+    return this._value!;
+  }
+
+  unwrapOr(defaultValue: T): T {
+    return this._isSuccess ? this._value! : defaultValue;
+  }
+
+  unwrapErr(): E {
+    if (this._isSuccess) {
+      throw new Error('Called unwrapErr on a success result');
+    }
+    return this._error!;
+  }
+
+  map<U>(fn: (value: T) => U): Result<U, E> {
+    if (this._isSuccess) {
+      return Result.ok(fn(this._value!));
+    }
+    return Result.err(this._error!);
+  }
+
+  mapErr<F>(fn: (error: E) => F): Result<T, F> {
+    if (!this._isSuccess) {
+      return Result.err(fn(this._error!));
+    }
+    return Result.ok(this._value!);
+  }
+
+  andThen<U>(fn: (value: T) => Result<U, E>): Result<U, E> {
+    if (this._isSuccess) {
+      return fn(this._value!);
+    }
+    return Result.err(this._error!);
+  }
+
+  /**
+   * Direct access to the value (for testing convenience).
+   * Prefer using unwrap() in production code.
+   */
+  get value(): T | undefined {
+    return this._value;
+  }
+
+  /**
+   * Direct access to the error (for testing convenience).
+   * Prefer using unwrapErr() in production code.
+   */
+  get error(): E | undefined {
+    return this._error;
+  }
+}