GraphQL fix for empty queries.

src/Squidex.Domain.Apps.Read/Contents/GraphQL/CachingGraphQLService.cs

@@ -78,6 +78,11 @@ namespace Squidex.Domain.Apps.Read.Contents.GraphQL
             Guard.NotNull(app, nameof(app));
             Guard.NotNull(query, nameof(query));
 
+            if (string.IsNullOrWhiteSpace(query.Query))
+            {
+                return (new object(), new object[0]);
+            }
+
             var modelContext = await GetModelAsync(app);
             var queryContext = new QueryContext(app, assetRepository, contentQuery, urlGenerator, user);
 

src/Squidex.Domain.Apps.Read/Contents/GraphQL/Types/ContentGraphType.cs

@@ -7,6 +7,7 @@
 // ==========================================================================
 
 using System;
+using System.Linq;
 using GraphQL.Resolvers;
 using GraphQL.Types;
 using Squidex.Domain.Apps.Read.Schemas;
@@ -87,13 +88,16 @@ namespace Squidex.Domain.Apps.Read.Contents.GraphQL.Types
                 Description = $"The url to the the {schemaName} content."
             });
 
-            AddField(new FieldType
+            if (schema.SchemaDef.Fields.Any(x => !x.IsHidden))
             {
-                Name = "data",
-                Resolver = Resolver(x => x.Data),
-                ResolvedType = new NonNullGraphType(new ContentDataGraphType(schema.SchemaDef, context)),
-                Description = $"The data of the {schemaName} content."
-            });
+                AddField(new FieldType
+                {
+                    Name = "data",
+                    Resolver = Resolver(x => x.Data),
+                    ResolvedType = new NonNullGraphType(new ContentDataGraphType(schema.SchemaDef, context)),
+                    Description = $"The data of the {schemaName} content."
+                });
+            }
 
             Description = $"The structure of a {schemaName} content type.";
         }

tests/Squidex.Domain.Apps.Read.Tests/Contents/GraphQLTests.cs

@@ -86,6 +86,24 @@ namespace Squidex.Domain.Apps.Read.Contents
             sut = new CachingGraphQLService(cache, assetRepository, contentQuery, new FakeUrlGenerator(), schemaRepository);
         }
 
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData(" ")]
+        public async Task Should_return_empty_object_for_empty_query(string query)
+        {
+            var result = await sut.QueryAsync(app, user, new GraphQLQuery { Query = query });
+
+            var expected = new
+            {
+                data = new
+                {
+                }
+            };
+
+            AssertJson(expected, new { data = result.Data });
+        }
+
         [Fact]
         public async Task Should_return_multiple_assets_when_querying_assets()
         {