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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Variable validation broken when variables are used inside an input object value","articleBody":"**Setup**\r\n\r\nI'll use the following simple schema to illustrate the issue:\r\n\r\n```graphql\r\ntype Query {\r\n  items(pagination: Pagination = {limit: 10, offset: 0}): [String]\r\n}\r\n\r\ninput Pagination {\r\n  limit: Int\r\n  offset: Int\r\n}\r\n```\r\n\r\nWhile variables are commonly used as the whole argument value:\r\n\r\n```graphql\r\nquery Items($pagination: Pagination) {\r\n  items(pagination: $pagination) { #variable is the entire input object (Pagination)\r\n    ...\r\n  }\r\n}\r\n```\r\n\r\nthey can also be used  as the values of fields inside an input object:\r\n\r\n```graphql\r\nquery Items($limit: Int) {\r\n  items(pagination: {limit: $limit, offset: 0}) { #variable is only a part of the input\r\n    ...\r\n  }\r\n}\r\n```\r\n\r\nI've scoured the spec for a confirmation on whether this is indeed legal usage of variables and, while this situation is never directly addressed either way, the section on [Input Coercion](https://spec.graphql.org/draft/#example-704b8) lists the following examples which seem to indicate this is legitimate usage:\r\n\r\n```graphql Definition\r\ninput ExampleInputObject {\r\n  a: String\r\n  b: Int!\r\n}\r\n```\r\n\r\n| Literal Value            | Variables               | Coerced Value                        |\r\n| ------------------------ | ----------------------- | ------------------------------------ |\r\n| `{ a: $var, b: 123 }`    | `{ var: null }`         | `{ a: null, b: 123 }`                |\r\n| `{ b: $var }`            | `{ var: 123 }`          | `{ b: 123 }`                         |\r\n\r\n**The bug**\r\n\r\nWhen a variable is used inside an input object **_which has a default value_** (like in my `Pagination` example), graphql-java's variable type validation freaks out, because it compares the type of the variable (`Int`) against the default value of the entire argument (`Pagination`) [here](https://github.com/graphql-java/graphql-java/blob/7f229de387e5e515e99ff270a1d1b9316b6e0338/src/main/java/graphql/validation/rules/VariableTypesMatch.java#L63):\r\n\r\n```java\r\n//Notice the getValidationContext().getArgument()\r\nOptional\u003cInputValueWithState\u003e schemaDefault = Optional.ofNullable(getValidationContext().getArgument()).map(v -\u003e v.getArgumentDefaultValue());\r\n...  \r\n//expectedType is Int\r\nschemaDefaultValue = ValuesResolver.valueToLiteral(schemaDefault.get(), expectedType, getValidationContext().getGraphQLContext(), getValidationContext().getI18n().getLocale());\r\n```\r\n\r\n**To Reproduce**\r\n\r\nHere's a self-contained example:\r\n\r\n```java\r\nGraphQLSchema schema = GraphQLSchema.newSchema()\r\n                .query(GraphQLObjectType.newObject()\r\n                        .name(\"Query\")\r\n                        .field(items -\u003e items\r\n                                .name(\"items\")\r\n                                .type(GraphQLList.list(Scalars.GraphQLString))\r\n                                .argument(pagination -\u003e pagination\r\n                                        .name(\"pagination\")\r\n                                        //skipped adding the default limit/offset values as it doesn't change anything\r\n                                        .defaultValueProgrammatic(new HashMap\u003c\u003e())\r\n                                        .type(GraphQLInputObjectType.newInputObject()\r\n                                                .name(\"Pagination\")\r\n                                                .field(limit -\u003e limit\r\n                                                        .name(\"limit\")\r\n                                                        .type(Scalars.GraphQLInt))\r\n                                                .field(offset -\u003e offset\r\n                                                        .name(\"offset\")\r\n                                                        .type(Scalars.GraphQLInt))\r\n                                                .build())))\r\n                        .build())\r\n                .codeRegistry(GraphQLCodeRegistry.newCodeRegistry()\r\n                        .dataFetcher(FieldCoordinates.coordinates(\"Query\", \"items\"), (DataFetcher\u003c?\u003e) env -\u003e Collections.singletonList(\"test\"))\r\n                        .build())\r\n                .build();\r\n\r\n        GraphQL gql = GraphQLRuntime.newGraphQL(schema).build();\r\n\r\n        Map\u003cString, Object\u003e vars = new HashMap\u003c\u003e();\r\n        vars.put(\"limit\", 5);\r\n        vars.put(\"offset\", 0);\r\n\r\n        ExecutionInput in = ExecutionInput.newExecutionInput()\r\n                .query(\"query Items( $limit: Int, $offset: Int) {\\n\" +\r\n                        \"  items(\\n\" +\r\n                        \"    pagination: {limit: $limit, offset: $offset} \\n\" +\r\n                        \"  )\\n\" +\r\n                        \"}\")\r\n                .variables(vars)\r\n                .build();\r\n        ExecutionResult result = gql.execute(in);\r\n```\r\n\r\nLeads to:\r\n\r\n\u003e graphql.AssertException: Expected a value that can be converted to type 'Int' but it was a 'HashMap'\r\n","author":{"url":"https://github.com/kaqqao","@type":"Person","name":"kaqqao"},"datePublished":"2023-07-30T16:11:44.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/3276/graphql-java/issues/3276"}