misc: add DynamoDbAttributeConverter annotation

hll/dynamodb-mapper/dynamodb-mapper-annotations/api/dynamodb-mapper-annotations.api

@@ -2,6 +2,10 @@ public abstract interface annotation class aws/sdk/kotlin/hll/dynamodbmapper/Dyn
 	public abstract fun name ()Ljava/lang/String;
 }
 
+public abstract interface annotation class aws/sdk/kotlin/hll/dynamodbmapper/DynamoDbAttributeConverter : java/lang/annotation/Annotation {
+	public abstract fun converter ()Ljava/lang/Class;
+}
+
 public abstract interface annotation class aws/sdk/kotlin/hll/dynamodbmapper/DynamoDbIgnore : java/lang/annotation/Annotation {
 }
 

hll/dynamodb-mapper/dynamodb-mapper-annotations/build.gradle.kts

@@ -6,3 +6,14 @@
 description = "DynamoDbMapper annotations"
 extra["displayName"] = "AWS :: SDK :: Kotlin :: HLL :: DynamoDbMapper :: Annotations"
 extra["moduleName"] = "aws.sdk.kotlin.hll.dynamodbmapper.annotations"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                // For ValueConverter
+                implementation(project(":hll:dynamodb-mapper:dynamodb-mapper"))
+            }
+        }
+    }
+}

hll/dynamodb-mapper/dynamodb-mapper-annotations/common/src/aws/sdk/kotlin/hll/dynamodbmapper/Annotations.kt

@@ -4,20 +4,28 @@
  */
 package aws.sdk.kotlin.hll.dynamodbmapper
 
+import aws.sdk.kotlin.hll.dynamodbmapper.values.ValueConverter
+import kotlin.reflect.KClass
+
 /**
  * Specifies the attribute name for a property in a [DynamoDbItem]-annotated class/interface. If this annotation is not
  * included then the attribute name matches the property name.
  */
 @Target(AnnotationTarget.PROPERTY)
 public annotation class DynamoDbAttribute(val name: String)
 
+/**
+ * Specifies the type of [ValueConverter] to be used when processing this attribute.
+ */
+public annotation class DynamoDbAttributeConverter(val converter: KClass<out ValueConverter<*>>)
+
 /**
  * Specifies that this class/interface describes an item type in a table. All public properties of this type will be mapped to
  * attributes unless they are explicitly ignored.
  * @param converterName The fully qualified name of the item converter to be used for converting this class/interface.
  * If not set, one will be automatically generated.
  */
-// FIXME Update to take a KClass<ItemConverter>, which will require splitting codegen modules due to a circular dependency
+// FIXME Update to take a KClass<ItemConverter>?
 @Target(AnnotationTarget.CLASS)
 public annotation class DynamoDbItem(val converterName: String = "")
 

hll/dynamodb-mapper/dynamodb-mapper-schema-codegen/build.gradle.kts

@@ -22,6 +22,7 @@ dependencies {
     implementation(project(":hll:hll-codegen"))
     implementation(project(":hll:dynamodb-mapper:dynamodb-mapper-annotations"))
     implementation(project(":hll:dynamodb-mapper:dynamodb-mapper-codegen"))
+    implementation(project(":hll:dynamodb-mapper:dynamodb-mapper")) // for ValueConverter.kt
 
     testImplementation(libs.junit.jupiter)
     testImplementation(libs.junit.jupiter.params)

hll/dynamodb-mapper/dynamodb-mapper-schema-codegen/src/main/kotlin/aws/sdk/kotlin/hll/dynamodbmapper/codegen/annotations/rendering/HighLevelRenderer.kt

@@ -42,7 +42,7 @@ internal class HighLevelRenderer(
                 attributes,
             )
 
-            val annotation = SchemaRenderer(annotated, renderCtx)
+            val annotation = SchemaRenderer(logger, annotated, renderCtx)
             annotation.render()
         }
     }

hll/dynamodb-mapper/dynamodb-mapper-schema-codegen/src/main/kotlin/aws/sdk/kotlin/hll/dynamodbmapper/codegen/annotations/rendering/SchemaRenderer.kt

@@ -4,6 +4,7 @@
  */
 package aws.sdk.kotlin.hll.dynamodbmapper.codegen.annotations.rendering
 
+import aws.sdk.kotlin.hll.codegen.core.ImportDirective
 import aws.sdk.kotlin.hll.codegen.model.*
 import aws.sdk.kotlin.hll.codegen.rendering.BuilderRenderer
 import aws.sdk.kotlin.hll.codegen.rendering.RenderContext
@@ -18,6 +19,7 @@ import com.google.devtools.ksp.KspExperimental
 import com.google.devtools.ksp.getAnnotationsByType
 import com.google.devtools.ksp.getConstructors
 import com.google.devtools.ksp.isAnnotationPresent
+import com.google.devtools.ksp.processing.KSPLogger
 import com.google.devtools.ksp.symbol.*
 
 /**
@@ -27,6 +29,7 @@ import com.google.devtools.ksp.symbol.*
  */
 @OptIn(KspExperimental::class)
 internal class SchemaRenderer(
+    private val logger: KSPLogger,
     private val classDeclaration: KSClassDeclaration,
     private val ctx: RenderContext,
 ) : RendererBase(ctx, "${classDeclaration.qualifiedName!!.getShortName()}Schema") {
@@ -148,6 +151,7 @@ internal class SchemaRenderer(
     }
 
     private fun renderAttributeDescriptor(prop: KSPropertyDeclaration) {
+        logger.info("Rendering an attribute descriptor for ${prop.simpleName.asString()}")
         withBlock("#T(", "),", MapperTypes.Items.AttributeDescriptor) {
             write("#S,", prop.ddbName) // key
             write("#L,", "$className::${prop.name}") // getter
@@ -160,8 +164,25 @@ internal class SchemaRenderer(
             }
 
             // converter
-            renderValueConverter(prop.type.resolve())
-            write(",")
+            // KSP requires extra work to get a class argument out of an annotation, can't just use getAnnotationsByType
+            // https://slack-chats.kotlinlang.org/t/8480301/hello-again-how-do-you-get-a-kclass-out-from-an-annotation-a
+            val attributeValueConverterFqn = prop.annotations
+                .singleOrNull { it.annotationType.resolve().declaration.qualifiedName?.asString() == DynamoDbAttributeConverter::class.qualifiedName }
+                ?.arguments
+                ?.single()
+                ?.value
+                ?.let { it as? KSType }
+                ?.declaration
+                ?.qualifiedName
+                ?.asString()
+
+            attributeValueConverterFqn?.let {
+                imports += ImportDirective(it)
+                write("$it(),")
+            } ?: run {
+                renderValueConverter(prop.type.resolve())
+                write(",")
+            }
         }
     }
 
@@ -229,7 +250,6 @@ internal class SchemaRenderer(
                     Types.Kotlin.UInt -> MapperTypes.Values.Scalars.UIntValueConverter
                     Types.Kotlin.UShort -> MapperTypes.Values.Scalars.UShortValueConverter
                     Types.Kotlin.ULong -> MapperTypes.Values.Scalars.ULongValueConverter
-
                     else -> error("Unsupported attribute type $type")
                 },
             )

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/build.gradle.kts

@@ -24,6 +24,7 @@ dependencies {
     implementation(libs.ksp.gradle.plugin)
 
     implementation(project(":hll:hll-codegen")) // for RenderOptions
+    implementation(project(":hll:dynamodb-mapper:dynamodb-mapper")) // for ValueConverter
     implementation(project(":hll:dynamodb-mapper:dynamodb-mapper-schema-codegen")) // for AnnotationsProcessorOptions
     implementation(libs.smithy.kotlin.runtime.core) // for AttributeKey
 

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/kotlin/aws/sdk/kotlin/hll/dynamodbmapper/plugins/SchemaGeneratorPluginTest.kt

@@ -569,4 +569,41 @@ class SchemaGeneratorPluginTest {
             """.trimIndent(),
         )
     }
+
+    @Test
+    fun testDynamoDbAttributeConverter() {
+        createClassFile("attribute-converter/Employee")
+        createClassFile("attribute-converter/HealthcareConverter")
+
+        val result = runner.build()
+        assertContains(setOf(TaskOutcome.SUCCESS, TaskOutcome.UP_TO_DATE), result.task(":build")?.outcome)
+
+        val schemaFile = File(testProjectDir, "build/generated/ksp/main/kotlin/org/example/dynamodbmapper/generatedschemas/EmployeeSchema.kt")
+        assertTrue(schemaFile.exists())
+
+        val schemaContents = schemaFile.readText()
+
+        assertContains(schemaContents, "import org.example.OccupationConverter")
+        assertContains(
+            schemaContents,
+            """        AttributeDescriptor(
+            "occupation",
+            Employee::occupation,
+            Employee::occupation::set,
+            org.example.OccupationConverter(),
+        ),""",
+        )
+
+        // Test cross-package converter
+        assertContains(schemaContents, "import a.different.pkg.HealthcareConverter")
+        assertContains(
+            schemaContents,
+            """        AttributeDescriptor(
+            "healthcare",
+            Employee::healthcare,
+            Employee::healthcare::set,
+            a.different.pkg.HealthcareConverter(),
+        ),""",
+        )
+    }
 }

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/resources/attribute-converter/Employee.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.example
+
+import a.different.pkg.HealthcareConverter
+import aws.sdk.kotlin.hll.dynamodbmapper.DynamoDbAttributeConverter
+import aws.sdk.kotlin.hll.dynamodbmapper.DynamoDbItem
+import aws.sdk.kotlin.hll.dynamodbmapper.DynamoDbPartitionKey
+import aws.sdk.kotlin.hll.dynamodbmapper.values.ValueConverter
+import aws.sdk.kotlin.hll.mapping.core.converters.MonoConverter
+import aws.sdk.kotlin.services.dynamodb.model.AttributeValue
+
+@DynamoDbItem
+data class Employee(
+    @DynamoDbPartitionKey
+    var id: Int = 1,
+    var givenName: String = "Johnny",
+    var surname: String = "Appleseed",
+
+    @property:DynamoDbAttributeConverter(OccupationConverter::class)
+    var occupation: Occupation = Occupation("Student", 0),
+
+    @property:DynamoDbAttributeConverter(HealthcareConverter::class)
+    var healthcare: Healthcare = Healthcare(false),
+)
+
+data class Occupation(val title: String, val salary: Int)
+data class Healthcare(val enrolled: Boolean)
+
+class OccupationConverter : ValueConverter<Occupation> {
+    override val right = MonoConverter<Occupation, AttributeValue> { AttributeValue.S(it.title + "#" + it.salary) }
+
+    override val left = MonoConverter<AttributeValue, Occupation> {
+        val content = it.asS()
+        val (title, salary) = content.split("#")
+        Occupation(title, salary.toInt())
+    }
+}

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/resources/attribute-converter/HealthcareConverter.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package a.different.pkg
+
+import aws.sdk.kotlin.hll.dynamodbmapper.values.ValueConverter
+import aws.sdk.kotlin.hll.mapping.core.converters.MonoConverter
+import aws.sdk.kotlin.services.dynamodb.model.AttributeValue
+import org.example.Healthcare
+
+class HealthcareConverter : ValueConverter<Healthcare> {
+    override val right = MonoConverter<Healthcare, AttributeValue> { AttributeValue.S(it.enrolled.toString()) }
+
+    override val left = MonoConverter<AttributeValue, Healthcare> {
+        val content = it.asS()
+        val enrolled = (content == "true")
+        Healthcare(enrolled)
+    }
+}