fix: nil as input

Author: Leeeon233

Sources/Loro/Container.swift

@@ -129,8 +129,6 @@ extension LoroMovableList: ContainerLike{
         return typedResult
     }
 }
-extension LoroCounter: ContainerLike{}
-extension LoroUnknown: ContainerLike{}
 
 
 extension LoroList: ContainerLike{
@@ -163,5 +161,31 @@ extension LoroList: ContainerLike{
     }
 }
 
+extension LoroCounter: ContainerLike{}
+extension LoroUnknown: ContainerLike{}
+
+// Extension for handling nil input
+// Although we extend Optional, we still need to specify the type explicitly
+// e.g. `nil as String?`. This is not convenient in some scenarios.
+extension LoroList{
+    public func insert(pos: UInt32, v: LoroValueLike?) throws {
+        try self.insert(pos: pos, v: v?.asLoroValue() ?? .null)
+    }
+}
+
+extension LoroMap{
+    public func insert(key: String, v: LoroValueLike?) throws {
+        try self.insert(key: key, v: v?.asLoroValue() ?? .null)
+    }
+}
 
+extension LoroMovableList{
+    public func insert(pos: UInt32, v: LoroValueLike?) throws {
+        try self.insert(pos: pos, v: v?.asLoroValue() ?? .null)
+    }
+
+    public func set(pos: UInt32, v: LoroValueLike?) throws {
+        try self.set(pos: pos, value: v?.asLoroValue() ?? .null)
+    }
+}
 

Sources/Loro/Value.swift

@@ -12,6 +12,16 @@ extension LoroValue: LoroValueLike {
     }
 }
 
+extension Optional: LoroValueLike where Wrapped: LoroValueLike {
+    public func asLoroValue() -> LoroValue {
+        if let value = self {
+            return value.asLoroValue()
+        } else {
+            return .null
+        }
+    }
+}
+
 extension Bool: LoroValueLike{
     public func asLoroValue() -> LoroValue {
         return LoroValue.bool(value: self)

Tests/LoroTests/LoroTests.swift

@@ -14,6 +14,21 @@ final class LoroTests: XCTestCase {
         sub.detach()
         XCTAssertEqual(num, 1)
     }
+
+    func testOptional(){
+        let doc = LoroDoc()
+        let list = doc.getList(id: "list")
+        try! list.insert(pos: 0, v: nil)
+        let map = doc.getMap(id: "map")
+        try! map.insert(key: "key", v: nil)
+        let movableList = doc.getMovableList(id: "movableList")
+        try! movableList.insert(pos: 0, v: nil)
+        try! movableList.set(pos: 0, v: nil)
+        doc.commit()
+        XCTAssertEqual(list.get(index: 0)!.asValue()!, LoroValue.null)
+        XCTAssertEqual(map.get(key: "key")!.asValue()!, LoroValue.null)
+        XCTAssertEqual(movableList.get(index: 0)!.asValue()!, LoroValue.null)
+    }
 
     func testText(){
         let doc = LoroDoc()