Hey! I’m Nathan 👋

While working on a GraphQL API project using Ktor and GraphQL Kotlin, I encountered a type redefinition error. The issue stemmed from an incorrect use of union types, which GraphQL does not support as input types. Debugging this was tricky, especially since the error message wasn’t particularly clear. This post breaks down the issue and how to resolve it. You have redefined the type ‘Pet’ from being a ‘GraphQLUnionType’ to a ‘GraphQLUnionType Exception in thread "main" graphql.AssertException: All types within a GraphQL schema must have unique names. No two provided types may have the same name. No provided type may have a name which conflicts with any built in types (including Scalar and Introspection types). You have redefined the type 'Pet' from being a 'GraphQLUnionType' to a 'GraphQLUnionType' at graphql.schema.impl.GraphQLTypeCollectingVisitor.assertUniqueTypeObjects(GraphQLTypeCollectingVisitor.java:156) at graphql.schema.impl.GraphQLTypeCollectingVisitor.assertTypeUniqueness(GraphQLTypeCollectingVisitor.java:148) at graphql.schema.impl.GraphQLTypeCollectingVisitor.visitGraphQLUnionType(GraphQLTypeCollectingVisitor.java:88) at graphql.schema.impl.MultiReadOnlyGraphQLTypeVisitor.lambda$visitGraphQLUnionType$15(MultiReadOnlyGraphQLTypeVisitor.java:142) at java.base/java.util.Arrays$ArrayList.forEach(Arrays.java:4204) at graphql.schema.impl.MultiReadOnlyGraphQLTypeVisitor.visitGraphQLUnionType(MultiReadOnlyGraphQLTypeVisitor.java:142) at graphql.schema.GraphQLUnionType.accept(GraphQLUnionType.java:185) at graphql.schema.SchemaTraverser$TraverserDelegateVisitor.enter(SchemaTraverser.java:109) at graphql.util.Traverser.traverse(Traverser.java:144) at graphql.schema.SchemaTraverser.doTraverse(SchemaTraverser.java:96) at graphql.schema.SchemaTraverser.depthFirst(SchemaTraverser.java:86) at graphql.schema.SchemaTraverser.depthFirst(SchemaTraverser.java:79) at graphql.schema.impl.SchemaUtil.visitPartiallySchema(SchemaUtil.java:68) at graphql.schema.GraphQLSchema$Builder.buildImpl(GraphQLSchema.java:927) at graphql.schema.GraphQLSchema$Builder.build(GraphQLSchema.java:904) at com.expediagroup.graphql.generator.SchemaGenerator.generateSchema(SchemaGenerator.kt:88) at com.expediagroup.graphql.generator.SchemaGenerator.generateSchema$default(SchemaGenerator.kt:58) at com.expediagroup.graphql.server.ktor.GraphQL$schema$1.invokeSuspend(GraphQL.kt:118) at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100) at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:586) at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:829) at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:717) at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:704) ...

I recently installed the cypress component testing library in a custom webpack project. In doing so I ran into a few issues. Here are my notes on what I did to solve these issues. Most of these notes can be found on the cypress component testing introduction documentation but with a few tweaks. Install Node Packages yarn add --dev cypress @cypress/react @cypress/webpack-dev-server webpack-dev-server html-webpack-plugin@^4.0 In my case I was using webpack version 4 but if you are using webpack version 5 then you can install html-webpack-plugin@^5.0. ...