extract handleFieldError function

Author: IvanGoncharov

src/execution/execute.js

@@ -814,34 +814,27 @@ function completeValueCatchingError(
       // to take a second callback for the error case.
       return completed.then(undefined, rawError => {
         const error = locatedFieldError(rawError, fieldNodes, path);
-
-        // If the field type is non-nullable, then it is resolved without any
-        // protection from errors, however it still properly locates the error.
-        if (isNonNullType(returnType)) {
-          throw error;
-        }
-
-        // Otherwise, error protection is applied, logging the error and
-        // resolving a null value for this field if one is encountered.
-        exeContext.errors.push(error);
-        return null;
+        return handleFieldError(error, returnType, exeContext);
       });
     }
     return completed;
   } catch (rawError) {
     const error = locatedFieldError(rawError, fieldNodes, path);
+    return handleFieldError(error, returnType, exeContext);
+  }
+}
 
-    // If the field type is non-nullable, then it is resolved without any
-    // protection from errors, however it still properly locates the error.
-    if (isNonNullType(returnType)) {
-      throw error;
-    }
-
-    // Otherwise, error protection is applied, logging the error and resolving
-    // a null value for this field if one is encountered.
-    exeContext.errors.push(error);
-    return null;
+function handleFieldError(error, returnType, exeContext) {
+  // If the field type is non-nullable, then it is resolved without any
+  // protection from errors, however it still properly locates the error.
+  if (isNonNullType(returnType)) {
+    throw error;
   }
+
+  // Otherwise, error protection is applied, logging the error and resolving
+  // a null value for this field if one is encountered.
+  exeContext.errors.push(error);
+  return null;
 }
 
 function locatedFieldError(errorValue, fieldNodes, path) {