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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"SchemaTransformer.transformSchema produces schema with dangling reference to deleted type","articleBody":"**Describe the bug**\nWe've implemented a visitor that prunes our schema based on the presence of a directive.\nThis has worked well until quite recently, but has suddenly started failing with `graphql.AssertException: Assert type Rom not found in schema`.\n\nI've analyzed the problem and reduced the schema and our visitor down to the minimal needed to reproduce the issue. Note that our actual implementation also handles other schema elements, but I don't think this is relevant for the issue at hand.\n\n**To Reproduce**\n\nGiven the following schema, our visitor crashes with `AssertException`:\n\n```graphql\ndirective @remove on FIELD_DEFINITION\n\ntype Query {\n  rental: Rental @remove\n  customer: Customer\n}\n\ntype Store {\n  inventory: Inventory @remove\n}\n\ntype Inventory {\n  store: Store @remove\n}\n\ntype Customer {\n  rental: Rental\n  payment: Payment @remove\n}\n\ntype Payment {\n  inventory: Inventory @remove\n}\n\ntype Rental {\n  id: ID\n  customer: Customer @remove\n}\n\n```\n\nOur visitor is defined as follows:\n\n```java\n    class SchemaPruningVisitor extends GraphQLTypeVisitorStub {\n        @Override\n        public TraversalControl visitGraphQLFieldDefinition(GraphQLFieldDefinition node, TraverserContext\u003cGraphQLSchemaElement\u003e context) {\n            if (node.hasAppliedDirective(\"remove\")) {\n                return deleteNode(context);\n            }\n\n            return CONTINUE;\n        }\n\n        @Override\n        public TraversalControl visitGraphQLObjectType(GraphQLObjectType node, TraverserContext\u003cGraphQLSchemaElement\u003e context) {\n            if (node.getFields().stream().allMatch(field -\u003e field.hasAppliedDirective(\"remove\"))) {\n                return deleteNode(context);\n            }\n\n            return CONTINUE;\n        }\n    }\n```\n\n## Interesting observation ##\n\nNote that if we flip the order of the `Query.rental` and `Query.customer` fields then our visitor no longer crashes and produces the schema we expect:\n\n```graphql\ntype Query {\n  customer: Customer\n}\n\ntype Customer {\n  rental: Rental\n}\n\ntype Rental {\n  id: ID\n}\n```","author":{"url":"https://github.com/alf","@type":"Person","name":"alf"},"datePublished":"2025-10-10T11:18:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/4133/graphql-java/issues/4133"}