fix: formatGraphQLErrors for persisted queries (#119)

* Fix formatGraphQLErrors for persisted queries

* Change implementation

* Minimize diff

Co-authored-by: Jordan Gensler <[email protected]>

Author: kesne

src/createRequestError.js

@@ -39,21 +39,22 @@ export function formatGraphQLErrors(request: RelayRequest, errors: GraphQLRespon
       const indent = ' '.repeat(prefix.length);
 
       // custom errors thrown in graphql-server may not have locations
-      const locationMessage = locations
-        ? '\n' +
-          locations
-            .map(({ column, line }) => {
-              const queryLine = queryLines[line - 1];
-              const offset = Math.min(column - 1, CONTEXT_BEFORE);
-              return [
-                queryLine.substr(column - 1 - offset, CONTEXT_LENGTH),
-                `${' '.repeat(Math.max(offset, 0))}^^^`,
-              ]
-                .map((messageLine) => indent + messageLine)
-                .join('\n');
-            })
-            .join('\n')
-        : '';
+      const locationMessage =
+        locations && queryLines.length
+          ? '\n' +
+            locations
+              .map(({ column, line }) => {
+                const queryLine = queryLines[line - 1];
+                const offset = Math.min(column - 1, CONTEXT_BEFORE);
+                return [
+                  queryLine.substr(column - 1 - offset, CONTEXT_LENGTH),
+                  `${' '.repeat(Math.max(offset, 0))}^^^`,
+                ]
+                  .map((messageLine) => indent + messageLine)
+                  .join('\n');
+              })
+              .join('\n')
+          : '';
       return prefix + message + locationMessage;
     })
     .join('\n');