From 229250a5baf350284cabee4c0010b859b2b2bb2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ivan=20=E2=80=9CCLOVIS=E2=80=9D=20Canet?=
 <ivan.canet@gmail.com>
Date: Sat, 12 Sep 2026 20:08:48 +0200
Subject: [PATCH] feat(driver-sync): Implement MongoCollection.unsafeCast()

---
 .../kotlin/BlockingMongoCollection.kt         |  3 +
 .../kotlin/SyncFilteredMongoCollectionImpl.kt |  4 ++
 .../src/jvmMain/kotlin/SyncMongoCollection.kt | 55 +++++++++++++++++++
 .../jvmMain/kotlin/SyncMongoCollectionImpl.kt |  5 ++
 4 files changed, 67 insertions(+)

diff --git a/driver-sync-api-adapter/src/commonMain/kotlin/BlockingMongoCollection.kt b/driver-sync-api-adapter/src/commonMain/kotlin/BlockingMongoCollection.kt
index ac1c18ed..082bef1c 100644
--- a/driver-sync-api-adapter/src/commonMain/kotlin/BlockingMongoCollection.kt
+++ b/driver-sync-api-adapter/src/commonMain/kotlin/BlockingMongoCollection.kt
@@ -170,6 +170,9 @@ class BlockingMongoCollection<Document : Any>(
 		BlockingUpsertResult(inner.upsertOneWithPipeline(options, filter, update))
 	}
 
+	override fun <NewType : Any> unsafeCast(type: KType): BlockingMongoCollection<NewType> =
+		BlockingMongoCollection(inner.unsafeCast(type))
+
 	override fun toString(): String =
 		inner.toString()
 }
diff --git a/driver-sync/src/jvmMain/kotlin/SyncFilteredMongoCollectionImpl.kt b/driver-sync/src/jvmMain/kotlin/SyncFilteredMongoCollectionImpl.kt
index 53210b48..a4d27ade 100644
--- a/driver-sync/src/jvmMain/kotlin/SyncFilteredMongoCollectionImpl.kt
+++ b/driver-sync/src/jvmMain/kotlin/SyncFilteredMongoCollectionImpl.kt
@@ -90,6 +90,10 @@ private class SyncFilteredMongoCollectionImpl<Document : Any>(
 	override val context: BsonContext
 		get() = upstream.context
 
+	@Suppress("UNCHECKED_CAST")
+	override fun <NewType : Any> unsafeCast(type: KType): SyncMongoCollection<NewType> =
+		SyncFilteredMongoCollectionImpl(upstream.unsafeCast(type), globalFilter as FilterQuery<NewType>.() -> Unit)
+
 	override fun create(options: CreateCollectionOptions<Document>.() -> Unit) =
 		error("It is not possible to call 'create' on the filtered collection $this:\nA filtered collection is a driver-side view, it cannot exist in the database itself.")
 
diff --git a/driver-sync/src/jvmMain/kotlin/SyncMongoCollection.kt b/driver-sync/src/jvmMain/kotlin/SyncMongoCollection.kt
index c643d769..4f8ac969 100644
--- a/driver-sync/src/jvmMain/kotlin/SyncMongoCollection.kt
+++ b/driver-sync/src/jvmMain/kotlin/SyncMongoCollection.kt
@@ -28,6 +28,8 @@ import opensavvy.ktmongo.dsl.query.UpdateWithPipelineQuery
 import opensavvy.ktmongo.dsl.query.UpsertQuery
 import opensavvy.ktmongo.sync.api.MongoCollection
 import opensavvy.ktmongo.sync.api.operations.UpdateOperations
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
 
 /**
  * A collection stores related documents together.
@@ -99,4 +101,57 @@ interface SyncMongoCollection<Document : Any> : MongoCollection<Document> {
 	override fun find(): SyncMongoFindIterable<Document>
 
 	override fun find(options: FindOptions<Document>.() -> Unit, filter: FilterQuery<Document>.() -> Unit): SyncMongoFindIterable<Document>
+
+	/**
+	 * Overwrites the represented type of this value.
+	 *
+	 * This method can be useful to bypass type checks.
+	 *
+	 * ### Example
+	 *
+	 * If we know there are some documents that have the wrong format, we can use `unsafeCast` to find them
+	 * without needing to add their fields to the production DTO.
+	 *
+	 * ```kotlin
+	 * class User(
+	 *     val _id: ObjectId,
+	 *     val name: String,
+	 * )
+	 *
+	 * users.unsafeCast<BsonDocument>() // Treat all data as arbitrary BSON documents
+	 *     .find { BsonDocument.get<String?>("oldField") ne null }
+	 *     .forEach {
+	 *         println(it["oldField"]?.decodeString())
+	 *     }
+	 * ```
+	 */
+	override fun <NewType : Any> unsafeCast(type: KType): SyncMongoCollection<NewType>
+
+	/**
+	 * Overwrites the represented type of this value.
+	 *
+	 * This method can be useful to bypass type checks.
+	 *
+	 * ### Example
+	 *
+	 * If we know there are some documents that have the wrong format, we can use `unsafeCast` to find them
+	 * without needing to add their fields to the production DTO.
+	 *
+	 * ```kotlin
+	 * class User(
+	 *     val _id: ObjectId,
+	 *     val name: String,
+	 * )
+	 *
+	 * users.unsafeCast<BsonDocument>() // Treat all data as arbitrary BSON documents
+	 *     .find { BsonDocument.get<String?>("oldField") ne null }
+	 *     .forEach {
+	 *         println(it["oldField"]?.decodeString())
+	 *     }
+	 * ```
+	 */
+	@Suppress("WRONG_MODIFIER_CONTAINING_DECLARATION")
+	final inline fun <reified T : Any> unsafeCast(): SyncMongoCollection<T> =
+		unsafeCast(typeOf<T>())
+
 }
diff --git a/driver-sync/src/jvmMain/kotlin/SyncMongoCollectionImpl.kt b/driver-sync/src/jvmMain/kotlin/SyncMongoCollectionImpl.kt
index f1d68fb6..595ec8a0 100644
--- a/driver-sync/src/jvmMain/kotlin/SyncMongoCollectionImpl.kt
+++ b/driver-sync/src/jvmMain/kotlin/SyncMongoCollectionImpl.kt
@@ -47,6 +47,7 @@ import opensavvy.ktmongo.official.toJava
 import opensavvy.ktmongo.official.toKtMongo
 import opensavvy.ktmongo.sync.api.operations.UpdateOperations
 import java.util.concurrent.TimeUnit
+import kotlin.reflect.KClass
 import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 import com.mongodb.client.model.ReplaceOptions as MongoReplaceOptions
@@ -82,6 +83,10 @@ private class SyncMongoCollectionImpl<Document : Any>(
 	@LowLevelApi
 	override val context: BsonContext = CoroutineBsonContext()
 
+	@Suppress("UNCHECKED_CAST")
+	override fun <NewType : Any> unsafeCast(type: KType): SyncMongoCollection<NewType> =
+		SyncMongoCollectionImpl(inner.withDocumentClass((type.classifier as KClass<NewType>).java), factory, propertyNameStrategy, objectIdGenerator, type, innerDatabase)
+
 	// region Count
 
 	override fun count(): Long =
-- 
2.51.2