add mana core

packages/shared-errors/src/index.ts

@@ -0,0 +1,108 @@
+/**
+ * @manacore/shared-errors
+ *
+ * Go-like error handling system for NestJS backends.
+ *
+ * Features:
+ * - Result<T, E> type for explicit error handling
+ * - Standardized error codes and HTTP status mappings
+ * - Error wrapping with context (like Go's fmt.Errorf)
+ * - Type guards for type-safe error checking (like Go's errors.Is/As)
+ * - NestJS exception filter for consistent API responses
+ *
+ * @example
+ * ```typescript
+ * // In a service
+ * import {
+ *   Result, ok, err, AsyncResult,
+ *   ValidationError, NotFoundError, ServiceError
+ * } from '@manacore/shared-errors';
+ *
+ * async function getUser(id: string): AsyncResult<User> {
+ *   if (!isValidId(id)) {
+ *     return err(ValidationError.invalidInput('id', 'must be a valid UUID'));
+ *   }
+ *
+ *   const user = await db.findUser(id);
+ *   if (!user) {
+ *     return err(new NotFoundError('User', id));
+ *   }
+ *
+ *   return ok(user);
+ * }
+ *
+ * // In a controller
+ * import { isOk } from '@manacore/shared-errors';
+ *
+ * const result = await userService.getUser(id);
+ * if (!isOk(result)) {
+ *   throw result.error; // Caught by AppExceptionFilter
+ * }
+ * return result.value;
+ * ```
+ */
+
+// Types
+export {
+  ErrorCode,
+  ERROR_CODE_TO_HTTP_STATUS,
+  ERROR_CODE_RETRYABLE,
+} from './types/error-codes';
+
+export {
+  type Result,
+  type AsyncResult,
+  ok,
+  err,
+  isOk,
+  isErr,
+  unwrap,
+  unwrapOr,
+  unwrapOrElse,
+  map,
+  mapErr,
+  andThen,
+  match,
+  tryCatch,
+  tryCatchAsync,
+  combine,
+  fromNullable,
+  toNullable,
+} from './types/result';
+
+// Errors
+export {
+  AppError,
+  type ErrorContext,
+  type AppErrorOptions,
+} from './errors/app-error';
+
+export { ValidationError } from './errors/validation-error';
+export { AuthError } from './errors/auth-error';
+export { NotFoundError } from './errors/not-found-error';
+export { CreditError } from './errors/credit-error';
+export { ServiceError } from './errors/service-error';
+export { RateLimitError } from './errors/rate-limit-error';
+export { NetworkError } from './errors/network-error';
+export { DatabaseError } from './errors/database-error';
+
+// Guards
+export {
+  isAppError,
+  isValidationError,
+  isAuthError,
+  isNotFoundError,
+  isCreditError,
+  isServiceError,
+  isRateLimitError,
+  isNetworkError,
+  isDatabaseError,
+  hasErrorCode,
+  findError,
+  isRetryable,
+  getHttpStatus,
+  getErrorCode,
+} from './guards/type-guards';
+
+// Utils
+export { wrap, toAppError, cause, rootCause } from './utils/wrap';