feat: add ImportApiErrorResponse (resolves #7)

Author: belyaev-dev

src/typings/utility.ts

@@ -10,12 +10,19 @@ export type RequireAtLeastOne<T> = {
   [K in keyof T]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<keyof T, K>>>
 }[keyof T]
 
-export type ImportApiResponse<T> = {
-  success: boolean
+export type ImportApiResponse<T> = ImportApiSuccessResponse<T> | ImportApiErrorResponse
+
+export type ImportApiSuccessResponse<T> = {
+  success: true
   action: string
   result: T
 }
 
+export type ImportApiErrorResponse = {
+  success: false
+  error: string
+}
+
 export type ExportApiResponse<T> = {
   success: boolean
   info: T