feat: gracefully handle HTML error responses from remote Mirror Node server (#3962)

quiet-node · web-flow · commit 8ef3c38b0e1f · 2025-07-22T10:55:04.000-04:00
Signed-off-by: Logan Nguyen &lt;logan.nguyen@swirldslabs.com&gt;
diff --git a/packages/relay/src/lib/clients/mirrorNodeClient.ts b/packages/relay/src/lib/clients/mirrorNodeClient.ts
@@ -378,9 +378,16 @@ export class MirrorNodeClient {
             (data) => {
               // if the data is not valid, just return it to stick to the current behaviour
               if (data) {
-                return JSONBigInt.parse(data);
+                try {
+                  return JSONBigInt.parse(data);
+                } catch (error) {
+                  this.logger.warn(
+                    `${requestDetails.formattedRequestId} Failed to parse response data from Mirror Node: ${error}`,
+                  );
+                }
               }
 
+              // Return raw data so response can be processed properly by subsequent operations.
               return data;
             },
           ];
diff --git a/packages/relay/tests/lib/mirrorNodeClient.spec.ts b/packages/relay/tests/lib/mirrorNodeClient.spec.ts
@@ -204,6 +204,27 @@ describe('MirrorNodeClient', async function () {
         }
       });
     }
+
+    it('should gracefully handle HTML error responses', async () => {
+      // Simulate Mirror Node returning HTML error page
+      mock
+        .onGet('accounts')
+        .reply(
+          502,
+          `<!DOCTYPE html><html><head><title>502 Server Error</title></head><body>Error: Server Error</body></html>`,
+        );
+      await expect(mirrorNodeInstance.get('accounts', 'accounts', requestDetails))
+        .to.eventually.be.rejectedWith('Request failed with status code 502')
+        .and.have.property('statusCode', 502);
+    });
+
+    it('should gracefully handle empty error responses', async () => {
+      // Simulate Mirror Node returning HTML error page
+      mock.onGet('accounts').reply(503, ``);
+      await expect(mirrorNodeInstance.get('accounts', 'accounts', requestDetails))
+        .to.eventually.be.rejectedWith('Request failed with status code 503')
+        .and.have.property('statusCode', 503);
+    });
   });
 
   it('Can extract the account number out of an account pagination next link url', async () => {
