fix(graphql): handle invalid schemas gracefully in query editor (#7269)

Prevent app crashes when loading GraphQL schemas with validation errors
(e.g., object types with no fields). The fix:

- Validates schemas using validateSchema() and shows warnings for issues
- Still loads the schema so autocomplete continues to work
- Wraps the CodeMirror GraphQL linter with error handling to catch
  any validation errors during linting

Fixes #4529

Co-authored-by: Chirag Chandrashekhar <cchirag85@gmail.com>

packages/bruno-app/src/components/RequestPane/GraphQLSchemaActions/useGraphqlSchema.js

@@ -1,9 +1,28 @@
 import { useState } from 'react';
 import toast from 'react-hot-toast';
-import { buildClientSchema, buildSchema } from 'graphql';
+import { buildClientSchema, buildSchema, validateSchema } from 'graphql';
 import { fetchGqlSchema } from 'utils/network';
 import { simpleHash, safeParseJSON } from 'utils/common';
 
+const buildAndValidateSchema = (data) => {
+  let schema;
+  if (typeof data === 'object') {
+    schema = buildClientSchema(data);
+  } else {
+    schema = buildSchema(data);
+  }
+
+  // Validate the schema to catch issues like empty object types
+  // The GraphQL spec requires object types to have at least one field
+  const validationErrors = validateSchema(schema);
+  if (validationErrors.length > 0) {
+    const errorMessages = validationErrors.map((e) => e.message).join('; ');
+    console.warn('GraphQL schema has validation issues:', errorMessages);
+  }
+
+  return { schema, validationErrors };
+};
+
 const schemaHashPrefix = 'bruno.graphqlSchema';
 
 const useGraphqlSchema = (endpoint, environment, request, collection) => {
@@ -19,13 +38,11 @@ const useGraphqlSchema = (endpoint, environment, request, collection) => {
         return null;
       }
       let parsedData = safeParseJSON(saved);
-      if (typeof parsedData === 'object') {
-        return buildClientSchema(parsedData);
-      } else {
-        return buildSchema(parsedData);
-      }
-    } catch {
-      localStorage.setItem(localStorageKey, null);
+      const { schema } = buildAndValidateSchema(parsedData);
+      return schema;
+    } catch (err) {
+      localStorage.removeItem(localStorageKey);
+      console.warn('Failed to load cached GraphQL schema:', err.message);
       return null;
     }
   });
@@ -72,13 +89,19 @@ const useGraphqlSchema = (endpoint, environment, request, collection) => {
         data = await loadSchemaFromIntrospection();
       }
       if (data) {
-        if (typeof data === 'object') {
-          setSchema(buildClientSchema(data));
-        } else {
-          setSchema(buildSchema(data));
-        }
+        const { schema, validationErrors } = buildAndValidateSchema(data);
+        setSchema(schema);
         localStorage.setItem(localStorageKey, JSON.stringify(data));
-        toast.success('GraphQL Schema loaded successfully');
+
+        if (validationErrors.length > 0) {
+          const errorMessages = validationErrors.map((e) => e.message).join('; ');
+          toast(`Schema validation issues: ${errorMessages}`, {
+            icon: '⚠️',
+            duration: 5000
+          });
+        } else {
+          toast.success('GraphQL Schema loaded successfully');
+        }
       }
     } catch (err) {
       setError(err);

packages/bruno-app/src/components/RequestPane/QueryEditor/index.js

@@ -24,6 +24,25 @@ const CodeMirror = require('codemirror');
 const md = new MD();
 const AUTO_COMPLETE_AFTER_KEY = /^[a-zA-Z0-9_@(]$/;
 
+const createSafeGraphQLLinter = () => {
+  // Get the original GraphQL lint helper registered by codemirror-graphql
+  const originalLinter = CodeMirror.helpers?.lint?.graphql?.[0];
+
+  return (text, options) => {
+    try {
+      if (originalLinter) {
+        return originalLinter(text, options);
+      }
+      return [];
+    } catch (error) {
+      // Log the error but don't crash - return empty lint results
+      // This can happen if the schema has validation issues
+      console.warn('GraphQL lint error (schema may be invalid):', error.message);
+      return [];
+    }
+  };
+};
+
 export default class QueryEditor extends React.Component {
   constructor(props) {
     super(props);
@@ -57,6 +76,7 @@ export default class QueryEditor extends React.Component {
         minFoldSize: 4
       },
       lint: {
+        getAnnotations: createSafeGraphQLLinter(),
         schema: this.props.schema,
         validationRules: this.props.validationRules ?? null,
         // linting accepts string or FragmentDefinitionNode[]