feat(dsl): $rename

4sh · Jul 18, 2024 · 116d10a · 116d10a
1 parent 60d18fa
commit 116d10a
Show file tree

Hide file tree

Showing 3 changed files with 82 additions and 0 deletions.
diff --git a/dsl/README.md b/dsl/README.md
@@ -20,6 +20,7 @@
 ### Update
 
 - [`$inc`][fr.qsh.ktmongo.dsl.expr.UpdateExpression.inc]
+- [`$rename`][fr.qsh.ktmongo.dsl.expr.UpdateExpression.renameTo]
 - [`$set`][fr.qsh.ktmongo.dsl.expr.UpdateExpression.set]
 - [`$setOnInsert`][fr.qsh.ktmongo.dsl.expr.UpdateExpression.setOnInsert]
 - [`$unset`][fr.qsh.ktmongo.dsl.expr.UpdateExpression.unset]
diff --git a/dsl/src/main/kotlin/expr/UpdateExpression.kt b/dsl/src/main/kotlin/expr/UpdateExpression.kt
@@ -276,6 +276,54 @@ class UpdateExpression<T>(
 		}
 	}
 
+	// endregion
+	// region $rename
+
+	/**
+	 * Renames a field.
+	 *
+	 * ### Example
+	 *
+	 * ```kotlin
+	 * class User(
+	 *     val name: String,
+	 *     val age: Int,
+	 *     val ageOld: Int,
+	 * )
+	 *
+	 * collection.updateMany {
+	 *     User::ageOld renameTo User::age
+	 * }
+	 * ```
+	 *
+	 * ### External resources
+	 *
+	 * - [Official documentation](https://www.mongodb.com/docs/manual/reference/operator/update/rename/)
+	 */
+	@OptIn(LowLevelApi::class)
+	@KtMongoDsl
+	infix fun <@OnlyInputTypes V> KProperty1<T, V>.renameTo(newName: KProperty1<T, V>) {
+		accept(RenameExpressionNode(listOf(this.path() to newName.path()), codec))
+	}
+
+	@LowLevelApi
+	private class RenameExpressionNode(
+		val fields: List<Pair<Path, Path>>,
+		codec: CodecRegistry,
+	) : UpdateExpressionNode(codec) {
+		override fun simplify(): Expression? =
+			this.takeUnless { fields.isEmpty() }
+
+		override fun write(writer: BsonWriter) {
+			writer.writeDocument("\$rename") {
+				for ((before, after) in fields) {
+					writer.writeName(before.toString())
+					writer.writeString(after.toString())
+				}
+			}
+		}
+	}
+
 	// endregion
 
 	companion object {
@@ -293,6 +341,9 @@ class UpdateExpression<T>(
 			OperatorCombinator(UnsetExpressionNode::class) { sources, codec ->
 				UnsetExpressionNode(sources.flatMap { it.fields }, codec)
 			},
+			OperatorCombinator(RenameExpressionNode::class) { sources, codec ->
+				RenameExpressionNode(sources.flatMap { it.fields }, codec)
+			},
 		)
 	}
 }
diff --git a/dsl/src/test/kotlin/expr/UpdateExpressionTest.kt b/dsl/src/test/kotlin/expr/UpdateExpressionTest.kt
@@ -3,6 +3,7 @@ package fr.qsh.ktmongo.dsl.expr
 import fr.qsh.ktmongo.dsl.LowLevelApi
 import fr.qsh.ktmongo.dsl.expr.common.withLoggedContext
 import fr.qsh.ktmongo.dsl.path.div
+import fr.qsh.ktmongo.dsl.path.get
 import fr.qsh.ktmongo.dsl.writeDocument
 import io.kotest.core.spec.style.FunSpec
 import org.bson.BsonDocument
@@ -45,6 +46,7 @@ class UpdateExpressionTest : FunSpec({
 	val setOnInsert = "\$setOnInsert"
 	val inc = "\$inc"
 	val unset = "\$unset"
+	val rename = "\$rename"
 
 	test("Empty update") {
 		update<User> { } shouldBeBson """{}"""
@@ -209,4 +211,32 @@ class UpdateExpressionTest : FunSpec({
 			""".trimIndent()
 		}
 	}
+
+	context("Operator $rename") {
+		test("Single and nested field") {
+			update {
+				User::bestFriend / Friend::name renameTo User::name
+			} shouldBeBson """
+				{
+					"$rename": {
+						"bestFriend.name": "name"
+					}
+				}
+			""".trimIndent()
+		}
+
+		test("Multiple fields") {
+			update {
+				User::bestFriend / Friend::name renameTo User::name
+				User::friends[0] / Friend::name renameTo User::friends[1] / Friend::name
+			} shouldBeBson """
+				{
+					"$rename": {
+						"bestFriend.name": "name",
+						"friends.$0.name": "friends.$1.name"
+					}
+				}
+			""".trimIndent()
+		}
+	}
 })