test: add test fetch_json_error.test.ts, add: 503 handler

packages/providers/src/fetch_json.ts

@@ -9,7 +9,7 @@ const retryConfig = {
     numOfAttempts: RETRY_NUMBER,
     timeMultiple: BACKOFF_MULTIPLIER,
     retry: (e: ProviderError) => {
-        if ([500, 408].includes(e.cause)) {
+        if ([503, 500, 408].includes(e.cause)) {
             return true;
         }
 
@@ -26,7 +26,7 @@ export interface ConnectionInfo {
     headers?: { [key: string]: string | number };
 }
 
-class ProviderError extends Error {
+export class ProviderError extends Error {
     cause: number;
     constructor(message: string, options: any) {
         super(message, options);
@@ -56,16 +56,19 @@ export async function fetchJsonRpc(url: string, json: JsonRpcRequest, headers: o
         });
 
         const { ok, status } = res;
-        if (!ok) {
-            throw new ProviderError(await res.text(), { cause: status });
-        }
 
         if (status === 500) {
             throw new ProviderError(`Internal server error`, { cause: status });
         } else if (status === 408) {
             throw new ProviderError('Timeout error', { cause: status });
         } else if (status === 400) {
             throw new ProviderError('Request validation error', { cause: status });
+        } else if (status === 503) {
+            throw new ProviderError(`${url} unavailable`, { cause: status });
+        }
+
+        if (!ok) {
+            throw new ProviderError(await res.text(), { cause: status });
         }
 
         return res;

packages/providers/test/fetch_json_error.test.ts

@@ -0,0 +1,74 @@
+import { describe, expect, test, jest, afterEach } from '@jest/globals';
+import { fetchJsonRpc } from '../src/fetch_json';
+import unfetch from 'isomorphic-unfetch';
+import { ProviderError } from '../src/fetch_json'; 
+
+jest.mock('isomorphic-unfetch');
+
+describe('fetchJsonError', () => {
+    const RPC_URL = 'https://rpc.testnet.near.org';
+    const statusRequest = {
+        jsonrpc: '2.0',
+        id: 'dontcare',
+        method: 'status',
+        params: [],
+    };
+
+    afterEach(() => {
+        jest.clearAllMocks();
+    });
+
+    test('handles 500 Internal Server Error', async () => {
+        (unfetch as jest.Mock).mockReturnValue({
+            ok: false,
+            status: 500,
+            text: '',
+            json: {},
+        });
+
+        // @ts-expect-error test input
+        await expect(fetchJsonRpc(RPC_URL, statusRequest, undefined))
+            .rejects
+            .toThrowError(new ProviderError('Internal server error', { cause: 500 }));
+    });
+    test('handles 408 Timeout Error', async () => {
+        (unfetch as jest.Mock).mockReturnValue({
+            ok: false,
+            status: 408,
+            text: '',
+            json: {},
+        });
+        // @ts-expect-error test input
+        await expect(fetchJsonRpc(RPC_URL, statusRequest, undefined))
+            .rejects
+            .toThrowError(new ProviderError('Timeout error', { cause: 408 }));
+    });
+    // });
+
+    test('handles 400 Request Validation Error', async () => {
+        (unfetch as jest.Mock).mockReturnValue({
+            ok: false,
+            status: 400,
+            text: '',
+            json: {},
+        });
+         // @ts-expect-error test input
+         await expect(fetchJsonRpc(RPC_URL, statusRequest, undefined))
+            .rejects
+            .toThrowError(new ProviderError('Request validation error', { cause: 400 }));
+    });
+
+    test('handles 503 Service Unavailable', async () => {
+        (unfetch as jest.Mock).mockReturnValue({
+            ok: false,
+            status: 503,
+            text: '',
+            json: {},
+        });
+
+          // @ts-expect-error test input
+          await expect(fetchJsonRpc(RPC_URL, statusRequest, undefined))
+            .rejects
+            .toThrowError(new ProviderError(`${RPC_URL} unavailable`, { cause: 503 }));
+    });
+});