Simplify upsert API to use item and optional expression

- Change upsert method signature from (key, UpdateItemEnhancedRequest) to (item, Expression?)
- This maintains type safety by using the item type directly
- Removes exposure to low-level AWS UpdateItemEnhancedRequest
- Keeps the idiomatic Kotlin API with optional Expression parameter
- Updates both sync and async View interfaces
- Updates implementation in DynamoDbView to build UpdateItemEnhancedRequest internally
- Updates tests to use the simplified API

Author: podlech

tempest2/src/main/kotlin/app/cash/tempest2/AsyncView.kt

@@ -147,17 +147,17 @@ interface AsyncView<K : Any, I : Any> {
 
   /**
    * Performs an upsert operation using DynamoDB's UpdateItem operation.
-   * Executes the provided UpdateItem request and returns the result.
+   * Creates or updates an item with the provided data and optional condition.
    * 
    * This operation uses a single UpdateItem call. Any exceptions from
    * DynamoDB (including ConditionalCheckFailedException) are bubbled up
    * to the caller.
    * 
-   * @param key The key of the item to upsert
-   * @param updateRequest The UpdateItem request to execute
+   * @param item The item to upsert
+   * @param upsertExpression Optional condition expression for the upsert
    * @return The result of the UpdateItem operation
    */
-  suspend fun upsert(key: K, updateRequest: UpdateItemEnhancedRequest<*>): I = upsertAsync(key, updateRequest).await()
+  suspend fun upsert(item: I, upsertExpression: Expression? = null): I = upsertAsync(item, upsertExpression).await()
 
-  fun upsertAsync(key: K, updateRequest: UpdateItemEnhancedRequest<*>): CompletableFuture<I>
+  fun upsertAsync(item: I, upsertExpression: Expression? = null): CompletableFuture<I>
 }

tempest2/src/main/kotlin/app/cash/tempest2/View.kt

@@ -112,15 +112,15 @@ interface View<K : Any, I : Any> {
 
   /**
    * Performs an upsert operation using DynamoDB's UpdateItem operation.
-   * Executes the provided UpdateItem request and returns the result.
+   * Creates or updates an item with the provided data and optional condition.
    * 
    * This operation uses a single UpdateItem call. Any exceptions from
    * DynamoDB (including ConditionalCheckFailedException) are bubbled up
    * to the caller.
    * 
-   * @param key The key of the item to upsert
-   * @param updateRequest The UpdateItem request to execute
+   * @param item The item to upsert
+   * @param upsertExpression Optional condition expression for the upsert
    * @return The result of the UpdateItem operation
    */
-  fun upsert(key: K, updateRequest: UpdateItemEnhancedRequest<*>): I
+  fun upsert(item: I, upsertExpression: Expression? = null): I
 }

tempest2/src/main/kotlin/app/cash/tempest2/internal/DynamoDbView.kt

@@ -102,8 +102,13 @@ internal class DynamoDbView<K : Any, I : Any, R : Any>(
       return toItem(itemObject)
     }
 
-    override fun upsert(key: K, updateRequest: UpdateItemEnhancedRequest<*>): I {
-      val result = dynamoDbTable.updateItem(updateRequest as UpdateItemEnhancedRequest<R>)
+    override fun upsert(item: I, upsertExpression: Expression?): I {
+      val itemObject = itemCodec.toDb(item)
+      val request = UpdateItemEnhancedRequest.builder(tableSchema.itemType().rawClass())
+        .item(itemObject)
+        .conditionExpression(upsertExpression)
+        .build()
+      val result = dynamoDbTable.updateItem(request)
       return itemCodec.toApp(result)
     }
   }
@@ -169,8 +174,13 @@ internal class DynamoDbView<K : Any, I : Any, R : Any>(
       return dynamoDbTable.deleteItem(request).thenApply(::toItem)
     }
 
-    override fun upsertAsync(key: K, updateRequest: UpdateItemEnhancedRequest<*>): CompletableFuture<I> {
-      return dynamoDbTable.updateItem(updateRequest as UpdateItemEnhancedRequest<R>)
+    override fun upsertAsync(item: I, upsertExpression: Expression?): CompletableFuture<I> {
+      val itemObject = itemCodec.toDb(item)
+      val request = UpdateItemEnhancedRequest.builder(tableSchema.itemType().rawClass())
+        .item(itemObject)
+        .conditionExpression(upsertExpression)
+        .build()
+      return dynamoDbTable.updateItem(request)
         .thenApply { result ->
           itemCodec.toApp(result)
         }

tempest2/src/test/kotlin/app/cash/tempest2/DynamoDbViewTest.kt

@@ -187,18 +187,13 @@ class DynamoDbViewTest {
       "Pop"
     )
 
-    // Create an UpdateItem request with condition to only create if item doesn't exist
-    val updateRequest = UpdateItemEnhancedRequest.builder(MusicItem::class.java)
-      .item(musicTable.codec(AlbumInfo::class).toDb(albumInfo))
-      .conditionExpression(
-        Expression.builder()
-          .expression("attribute_not_exists(partition_key)")
-          .build()
-      )
+    // Create condition to only create if item doesn't exist
+    val condition = Expression.builder()
+      .expression("attribute_not_exists(partition_key)")
       .build()
 
     // Upsert should create the item since it doesn't exist
-    val result = musicTable.albumInfo.upsert(albumInfo.key, updateRequest)
+    val result = musicTable.albumInfo.upsert(albumInfo, condition)
     assertThat(result).isEqualTo(albumInfo)
 
     // Verify the item was created
@@ -228,20 +223,15 @@ class DynamoDbViewTest {
       "Jazz"
     )
 
-    // Create an UpdateItem request with condition to only create if item doesn't exist
-    val updateRequest = UpdateItemEnhancedRequest.builder(MusicItem::class.java)
-      .item(musicTable.codec(AlbumInfo::class).toDb(modifiedAlbumInfo))
-      .conditionExpression(
-        Expression.builder()
-          .expression("attribute_not_exists(partition_key)")
-          .build()
-      )
+    // Create condition to only create if item doesn't exist
+    val condition = Expression.builder()
+      .expression("attribute_not_exists(partition_key)")
       .build()
 
     // Upsert should throw ConditionalCheckFailedException since item already exists
     assertThatExceptionOfType(ConditionalCheckFailedException::class.java)
       .isThrownBy {
-        musicTable.albumInfo.upsert(originalAlbumInfo.key, updateRequest)
+        musicTable.albumInfo.upsert(modifiedAlbumInfo, condition)
       }
 
     // Verify the original item is still there unchanged
@@ -262,20 +252,15 @@ class DynamoDbViewTest {
     // Simulate concurrent creation by saving directly first
     musicTable.albumInfo.save(albumInfo)
 
-    // Create an UpdateItem request with condition to only create if item doesn't exist
-    val updateRequest = UpdateItemEnhancedRequest.builder(MusicItem::class.java)
-      .item(musicTable.codec(AlbumInfo::class).toDb(albumInfo))
-      .conditionExpression(
-        Expression.builder()
-          .expression("attribute_not_exists(partition_key)")
-          .build()
-      )
+    // Create condition to only create if item doesn't exist
+    val condition = Expression.builder()
+      .expression("attribute_not_exists(partition_key)")
       .build()
 
     // Now upsert should throw ConditionalCheckFailedException since item already exists
     assertThatExceptionOfType(ConditionalCheckFailedException::class.java)
       .isThrownBy {
-        musicTable.albumInfo.upsert(albumInfo.key, updateRequest)
+        musicTable.albumInfo.upsert(albumInfo, condition)
       }
   }
 }