Deduplicate projection methods and superinterfaces, fix Representation type gen

graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/CodeGen.kt

@@ -191,6 +191,8 @@ class CodeGen(
      * the schema information for the parser.
      */
     private fun loadSchemaReaders(vararg readerBuilders: MultiSourceReader.Builder) {
+        validateNoOverlappingPaths(config.schemaFiles)
+
         readerBuilders.forEach { rb ->
             val schemaFiles =
                 config.schemaFiles
@@ -209,6 +211,28 @@ class CodeGen(
         }
     }
 
+    /**
+     * Validates that there are no overlapping paths in the schema files to prevent duplicate loading.
+     * Throws an [IllegalArgumentException] if any path is an ancestor of another.
+     */
+    private fun validateNoOverlappingPaths(schemaFiles: Set<File>) {
+        val canonicalPaths = schemaFiles.map { it.canonicalFile }
+
+        for (i in canonicalPaths.indices) {
+            for (j in i + 1 until canonicalPaths.size) {
+                val path1 = canonicalPaths[i]
+                val path2 = canonicalPaths[j]
+
+                if (path1.startsWith(path2) || path2.startsWith(path1)) {
+                    val (parent, child) = if (path1.startsWith(path2)) path2 to path1 else path1 to path2
+                    logger.warn(
+                        "Schema path '$child' is a descendant of '$parent'. Remove one of these paths from your configuration to avoid loading duplicate schema files.",
+                    )
+                }
+            }
+        }
+    }
+
     private fun generateJava(): CodeGenResult {
         val definitions = document.definitions
         // data types

graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/generators/java/ClientApiGenerator.kt

@@ -681,9 +681,11 @@ class ClientApiGenerator(
     ): CodeGenResult =
         if (type is InterfaceTypeDefinition) {
             val concreteTypes =
-                document.getDefinitionsOfType(ObjectTypeDefinition::class.java).filter {
-                    it.implements.filterIsInstance<NamedNode<*>>().any { iface -> iface.name == type.name }
-                }
+                document
+                    .getDefinitionsOfType(ObjectTypeDefinition::class.java)
+                    .filter {
+                        it.implements.filterIsInstance<NamedNode<*>>().any { iface -> iface.name == type.name }
+                    }.distinctBy { it.name }
             concreteTypes
                 .map {
                     addFragmentProjectionMethod(javaType, root, it, processedEdges, queryDepth)

graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/generators/java/DataTypeGenerator.kt

@@ -92,6 +92,7 @@ class DataTypeGenerator(
                         .map { it as TypeName }
                         .any { it.name == name }
                 }.map { it.name }
+                .distinct()
                 .toList()
 
         var implements =

graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/generators/java/EntitiesRepresentationTypeGenerator.kt

@@ -77,11 +77,7 @@ class EntitiesRepresentationTypeGenerator(
                         )
                     ) {
                         val fieldTypeRepresentationName = toRepresentationName(type)
-                        val fieldRepresentationType =
-                            typeUtils
-                                .findReturnType(it.type)
-                                .toString()
-                                .replace(type.name, fieldTypeRepresentationName)
+                        val fieldRepresentationType = typeUtils.qualifyName(fieldTypeRepresentationName)
 
                         if (generatedRepresentations.containsKey(fieldTypeRepresentationName)) {
                             logger.trace("Representation for {} was already generated.", fieldTypeRepresentationName)

graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/generators/kotlin/KotlinDataTypeGenerator.kt

@@ -266,12 +266,14 @@ abstract class AbstractKotlinDataTypeGenerator(
         }
 
         val unionTypes =
-            document.getDefinitionsOfType(UnionTypeDefinition::class.java).filter { union ->
-                union.memberTypes
-                    .asSequence()
-                    .map { it as TypeName }
-                    .any { it.name == name }
-            }
+            document
+                .getDefinitionsOfType(UnionTypeDefinition::class.java)
+                .filter { union ->
+                    union.memberTypes
+                        .asSequence()
+                        .map { it as TypeName }
+                        .any { it.name == name }
+                }.distinctBy { it.name }
 
         val interfaceTypes = interfaces + unionTypes
         interfaceTypes.forEach {

graphql-dgs-codegen-core/src/main/kotlin/com/netflix/graphql/dgs/codegen/generators/kotlin/KotlinEntitiesRepresentationTypeGenerator.kt

@@ -80,11 +80,7 @@ class KotlinEntitiesRepresentationTypeGenerator(
                     ) {
                         val fieldType = typeUtils.findReturnType(it.type)
                         val fieldTypeRepresentationName = toRepresentationName(type)
-                        val fieldRepresentationType =
-                            fieldType
-                                .toString()
-                                .replace(type.name, fieldTypeRepresentationName)
-                                .removeSuffix("?")
+                        val fieldRepresentationType = typeUtils.qualifyName(fieldTypeRepresentationName)
 
                         if (generatedRepresentations.containsKey(fieldTypeRepresentationName)) {
                             logger.trace("Representation for {} was already generated.", fieldTypeRepresentationName)

graphql-dgs-codegen-core/src/test/kotlin/com/netflix/graphql/dgs/codegen/EntitiesClientApiGenTest.kt

@@ -583,6 +583,46 @@ class EntitiesClientApiGenTest {
         }
     }
 
+    @Test
+    fun `Entity representation types should use client package not type-mapped package`() {
+        val schema =
+            """
+            type Channel @key(fields: "id type") {
+                id: ID! @external
+                type: ChatType @external
+                name: String
+            }
+
+            enum ChatType {
+                PUBLIC
+                PRIVATE
+                DM
+            }
+            """.trimIndent()
+
+        val codeGenResult =
+            CodeGen(
+                CodeGenConfig(
+                    schemas = setOf(schema),
+                    packageName = BASE_PACKAGE_NAME,
+                    generateClientApi = true,
+                    generateDataTypes = false,
+                    typeMapping = mapOf("ChatType" to "com.external.types.ChatType"),
+                ),
+            ).generate()
+
+        val representations = codeGenResult.javaDataTypes.filter { "Representation" in it.typeSpec.name }
+        assertThat(representations).hasSize(2)
+
+        val channelRepresentation = representations.find { it.typeSpec.name == "ChannelRepresentation" }
+        assertThat(channelRepresentation).isNotNull
+
+        val typeField = channelRepresentation!!.typeSpec.fieldSpecs.find { it.name == "type" }
+        assertThat(typeField).isNotNull
+        assertThat(typeField!!.type.toString())
+            .isEqualTo("$BASE_PACKAGE_NAME.client.ChatTypeRepresentation")
+    }
+
     companion object {
         fun codeGen(schema: String): CodeGenResult =
             CodeGen(