Initial implementation

src/domain/errors.ts

@@ -0,0 +1,23 @@
+export class GatewayError extends Error {
+  public constructor(
+    public readonly statusCode: number,
+    public readonly code: string,
+    message: string,
+    public readonly details: Record<string, unknown> = {},
+  ) {
+    super(message);
+    this.name = 'GatewayError';
+  }
+}
+
+export const badRequest = (code: string, message: string, details: Record<string, unknown> = {}) =>
+  new GatewayError(400, code, message, details);
+
+export const forbidden = (code: string, message: string) => new GatewayError(403, code, message);
+export const notFound = (code: string, message: string) => new GatewayError(404, code, message);
+export const conflict = (code: string, message: string) => new GatewayError(409, code, message);
+export const unprocessable = (code: string, message: string) => new GatewayError(422, code, message);
+
+export function asError(value: unknown): Error {
+  return value instanceof Error ? value : new Error(String(value));
+}