refactor: throw a custom S5Error

src/axios.ts

@@ -1,4 +1,5 @@
-import Axios, { AxiosRequestConfig } from "axios";
+import Axios, {AxiosError, AxiosRequestConfig} from "axios";
+import {S5Error} from "#client.js";
 
 export const customInstance = <T>(
     config: AxiosRequestConfig,
@@ -20,7 +21,12 @@ export const customInstance = <T>(
         ...config,
         ...options,
         cancelToken: source.token,
-  }).then(({ data }) => data);
+    }).then(({data}) => data).catch((error) => {
+        if (Axios.isCancel(error)) {
+            return;
+        }
+        throw new S5Error((error as AxiosError).message, (error as AxiosError).response?.status as number);
+    })
 
     // @ts-ignore
     promise.cancel = () => {

src/client.ts

@@ -70,6 +70,16 @@ import { Multihash } from "@lumeweb/libs5/lib/multihash.js";
 import { blake3 } from "@noble/hashes/blake3";
 import { base64urlDecode, base64urlEncode } from "#utils/encoding.js";
 
+export class S5Error extends Error {
+    public statusCode: number;
+
+    constructor(message: string, statusCode: number) {
+        super(message);
+        this.name = "S5Error";
+        this.statusCode = statusCode;
+    }
+}
+
 /**
  * The S5 Client which can be used to access S5-net.
  */