René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Difference in catch and reporting behavior of Coercing value errors vs literal errors","articleBody":"**Describe the bug**\r\n\r\nI've recently noticed a difference in behavior (using release 18.0) between how exceptions are handled implementing a custom scalar which parses input fields values and literals.\r\n\r\nAs I understand them `parseLiteral` is used in the case where an input comes directly from a query. This works well [as described in the docs](https://www.graphql-java.com/documentation/scalars/) when the custom `Coercing` throws a `CoercingParseLiteralException` exception. The error is handled by the execution engine and serialized with normal graphql errors according to the spec in the responses `errors` array.\r\n\r\nHowever, when the same input comes from a query variable, `parseValue` is used and, as the [as described in the docs](https://www.graphql-java.com/documentation/scalars/) mention, I throw `CoercingParseValueException` exception. In the case the execution engine does not catch and handle the exception and instead it results in a 500 error from my server rather than a 200 response with a graphql errors spec response.\r\n\r\nbelow is an example stack trace if it helps\r\n\r\n```\r\n2022-04-23 17:27:49,743 - - - [jetty task-169] ERROR org.jooby.Err  - execution of: POST/ resulted in exception\r\nRoute:\r\n      | Method | Path | Source                                     | Name       | Pattern | Consumes | Produces |\r\n      |--------|------|--------------------------------------------|------------|---------|----------|----------|\r\n      | POST   | /    | com.meetup.graphql.server.GraphqlServer:66 | /anonymous | /       | [*/*]    | [*/*]    |\r\n\r\nStacktrace:\r\norg.jooby.Err: Server Error(500)\r\n        \u003csnip\u003e\r\nCaused by: graphql.schema.CoercingParseValueException: Variable 'startDateTime' has an invalid value: Try something like '2022-04-24T17:27' instead\r\n        at graphql.schema.CoercingParseValueException$Builder.build(CoercingParseValueException.java:46)\r\n        at graphql.execution.ValuesResolver.externalValueToInternalValueForVariables(ValuesResolver.java:420)\r\n        at graphql.execution.ValuesResolver.coerceVariableValues(ValuesResolver.java:94)\r\n        at graphql.analysis.QueryTraverser.coerceVariables(QueryTraverser.java:64)\r\n        at graphql.analysis.QueryTraverser.\u003cinit\u003e(QueryTraverser.java:60)\r\n        at graphql.analysis.QueryTraverser.\u003cinit\u003e(QueryTraverser.java:40)\r\n        at graphql.analysis.QueryTraverser$Builder.build(QueryTraverser.java:297)\r\n        at graphql.analysis.MaxQueryComplexityInstrumentation.newQueryTraverser(MaxQueryComplexityInstrumentation.java:134)\r\n        at graphql.analysis.MaxQueryComplexityInstrumentation.lambda$beginValidation$4(MaxQueryComplexityInstrumentation.java:85)\r\n        at graphql.execution.instrumentation.SimpleInstrumentationContext.onCompleted(SimpleInstrumentationContext.java:51)\r\n        at graphql.execution.instrumentation.ChainedInstrumentation$ChainedInstrumentationContext.lambda$onCompleted$1(ChainedInstrumentation.java:238)\r\n        at graphql.com.google.common.collect.ImmutableList.forEach(ImmutableList.java:422)\r\n        at graphql.execution.instrumentation.ChainedInstrumentation$ChainedInstrumentationContext.onCompleted(ChainedInstrumentation.java:238)\r\n        at graphql.GraphQL.validate(GraphQL.java:628)\r\n        at graphql.GraphQL.parseAndValidate(GraphQL.java:589)\r\n        at graphql.GraphQL.lambda$parseValidateAndExecute$10(GraphQL.java:553)\r\n        at com.meetup.graphql.server.GraphqlServer.lambda$new$0(GraphqlServer.java:59)\r\n        at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1134)\r\n        at java.base/java.util.Collections$SynchronizedMap.computeIfAbsent(Collections.java:2682)\r\n        at com.meetup.graphql.server.GraphqlServer.lambda$new$1(GraphqlServer.java:59)\r\n        at graphql.execution.preparsed.PreparsedDocumentProvider.getDocumentAsync(PreparsedDocumentProvider.java:45)\r\n        at graphql.GraphQL.parseValidateAndExecute(GraphQL.java:555)\r\n        at graphql.GraphQL.executeAsync(GraphQL.java:524)\r\n        at graphql.GraphQL.execute(GraphQL.java:450)\r\n        at com.meetup.graphql.server.GraphqlQueryExecutor.toExecutionResult(GraphqlQueryExecutor.java:93)\r\n        at com.meetup.graphql.server.GraphqlHandler.handle(GraphqlHandler.java:82)\r\n        at com.meetup.graphql.server.GraphqlServer.lambda$new$2(GraphqlServer.java:79)\r\n        at org.jooby.Route$Handler.handle(Route.java:1761)\r\n        at org.jooby.internal.RouteImpl.handle(RouteImpl.java:280)\r\n        at org.jooby.internal.RouteChain.next(RouteChain.java:262)\r\n        at org.jooby.Route$Chain.next(Route.java:2164)\r\n        at org.jooby.internal.HttpHandlerImpl.handle(HttpHandlerImpl.java:496)\r\n        ... 19 more\r\nCaused by: java.time.format.DateTimeParseException: Text '2022-05-01T05:30+400' could not be parsed, unparsed text found at index 16\r\n        at java.base/java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:2049)\r\n        at java.base/java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1948)\r\n        at java.base/java.time.LocalDateTime.parse(LocalDateTime.java:492)\r\n```\r\n\r\n\r\n**To Reproduce**\r\n\r\nHere is what my `Coercing` scalar impl looks like. note parse value errors are reported with `CoercingParseValueException` and parse literal errors are reported with `CoercingParseLiteralException`\r\n\r\nwhen an invalid input is passed in a literal the execution engine does what I expect. when an invalid input is passed in through a variable, the exception bubbles all the way up to my server, resulting in a 500 error.\r\n\r\n```java\r\n  static java.time.LocalDateTime parseLocalDateTimeValue(Object input) {\r\n    String value =\r\n        input instanceof StringValue ? ((StringValue) input).getValue() : Objects.toString(input);\r\n    try {\r\n      if (input instanceof StringValue) {\r\n        return java.time.LocalDateTime.parse(value);\r\n      } else if (input instanceof String) {\r\n        return java.time.LocalDateTime.parse(value);\r\n      } else throw new IllegalArgumentException(\"Unexpected input type: \" + input.getClass());\r\n    } catch (Exception e) {\r\n      throw new CoercingParseValueException(\r\n          \"Try something like '\"\r\n              + java.time.LocalDateTime.now().truncatedTo(ChronoUnit.MINUTES).plusDays(1)\r\n              + \"' instead\",\r\n          e);\r\n    }\r\n  }\r\n\r\n  static java.time.LocalDateTime parseLocalDateTimeLiteral(Object input) {\r\n    String value =\r\n        input instanceof StringValue ? ((StringValue) input).getValue() : Objects.toString(input);\r\n    try {\r\n      if (input instanceof StringValue) {\r\n        return java.time.LocalDateTime.parse(value);\r\n      } else if (input instanceof String) {\r\n        return java.time.LocalDateTime.parse(value);\r\n      } else throw new IllegalArgumentException(\"Unexpected input type: \" + input.getClass());\r\n    } catch (Exception e) {\r\n      throw new CoercingParseLiteralException(\r\n          \"Try something like '\"\r\n              + java.time.LocalDateTime.now().truncatedTo(ChronoUnit.MINUTES).plusDays(1)\r\n              + \"' instead.\",\r\n          e);\r\n    }\r\n  }\r\n\r\n  public static final GraphQLScalarType LocalDateTime =\r\n      GraphQLScalarType.newScalar()\r\n          .name(\"LocalDateTime\")\r\n          .description(\"A custom scalar that handles timestamps that exclude timezone information\")\r\n          .coercing(\r\n              new Coercing\u003cjava.time.LocalDateTime, String\u003e() {\r\n                @Override\r\n                public String serialize(Object dataFetcherResult) {\r\n                  return null; // omitted as its not relevant to this issue\r\n                }\r\n\r\n                @Override\r\n                public java.time.LocalDateTime parseValue(Object input) {\r\n                  return parseLocalDateTimeValue(input);\r\n                }\r\n\r\n                @Override\r\n                public java.time.LocalDateTime parseLiteral(Object input) {\r\n                  return parseLocalDateTimeLiteral(input);\r\n                }\r\n              })\r\n          .build();\r\n```\r\n\r\n\r\n\r\n","author":{"url":"https://github.com/softprops","@type":"Person","name":"softprops"},"datePublished":"2022-04-23T21:34:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/2811/graphql-java/issues/2811"}