enhance: better error codes

Author: ardatan

.changeset/plenty-pianos-sleep.md

@@ -0,0 +1,10 @@
+---
+'@graphql-tools/executor-http': patch
+'@graphql-hive/gateway-runtime': patch
+---
+
+Use more specific error codes;
+
+`GATEWAY_TIMEOUT` -> Server could not get a response from upstream in time
+`SUBREQUEST_HTTP_ERROR` -> An error occurred while making the HTTP request to the upstream
+`RESPONSE_VALIDATION_FAILED` -> The response from upstream did not conform to the expected GraphQL response format

packages/executors/http/src/index.ts

@@ -323,6 +323,7 @@ export function buildHTTPExecutor(
     }
 
     function handleError(e: any) {
+      upstreamErrorExtensions.code = 'SUBREQUEST_HTTP_ERROR';
       if (e.name === 'AggregateError') {
         return {
           errors: e.errors.map((e: any) =>
@@ -426,6 +427,8 @@ export function buildHTTPExecutor(
                           parsedResult.errors.length === 0)
                       ) {
                         const message = `Unexpected empty "data" and "errors" fields in result: ${result}`;
+                        upstreamErrorExtensions.code =
+                          'RESPONSE_VALIDATION_FAILED';
                         return {
                           errors: [
                             createGraphQLError(message, {
@@ -451,6 +454,8 @@ export function buildHTTPExecutor(
                       }
                       return parsedResult;
                     } catch (e: any) {
+                      upstreamErrorExtensions.code =
+                        'RESPONSE_VALIDATION_FAILED';
                       return {
                         errors: [
                           createGraphQLError(
@@ -465,6 +470,7 @@ export function buildHTTPExecutor(
                     }
                   } else {
                     const message = 'No response returned';
+                    upstreamErrorExtensions.code = 'RESPONSE_VALIDATION_FAILED';
                     return {
                       errors: [
                         createGraphQLError(message, {

packages/runtime/src/plugins/useUpstreamTimeout.ts

@@ -105,7 +105,7 @@ export function useUpstreamTimeout<TContext extends Record<string, any>>(
                 throw createGraphQLError(e.message, {
                   extensions: {
                     ...upstreamErrorExtensions,
-                    code: 'TIMEOUT_ERROR',
+                    code: 'GATEWAY_TIMEOUT',
                     http: {
                       status: 504,
                     },