fix(display-list): make moveContents nonoptional

Author: Kyle-Ye

Package.resolved

@@ -154,7 +154,7 @@ public final class ORBDisplayList: NSObject, ORBDisplayListContents {
 
     // MARK: - Contents
 
-    public func moveContents() -> (any ORBDisplayListContents)? {
+    public func moveContents() -> any ORBDisplayListContents {
         _openRenderBoxUnimplementedFailure()
     }
 

Sources/OpenRenderBox/Render/ORBDisplayList.swift

@@ -56,7 +56,7 @@ ORB_ASSUME_NONNULL_BEGIN
 - (void)drawDisplayList:(id<ORBDisplayListContents>)list alpha:(float)alpha;
 - (void)drawInRect:(CGRect)rect alpha:(float)alpha blendMode:(int)mode flags:(unsigned int)flags operation:(id /* block */)operation;
 - (void)renderInContext:(CGContextRef)context options:(nullable id)options;
-- (nullable id<ORBDisplayListContents>)moveContents;
+- (id<ORBDisplayListContents>)moveContents;
 - (void)setIdentifier:(unsigned int)identifier namespace:(nullable NSUUID *)ns;
 - (void)beginRecordingXML;
 - (void)addAffineTransformStyle:(CGAffineTransform)style;

Sources/OpenRenderBoxCxx/include/OpenRenderBoxObjC/Render/ORBDisplayList.h

@@ -63,8 +63,20 @@ struct DisplayListTests {
         context.fill([CGRect(x: 0, y: 0, width: 10, height: 10)])
         displayList.endCGContext()
 
-        let contents = displayList.moveContents()
-        #expect(contents != nil)
+        let contents: any ORBDisplayListContents = displayList.moveContents()
+        #expect(!contents.isEmpty())
+        #expect(displayList.isEmpty())
+
+        let emptyContents: any ORBDisplayListContents = displayList.moveContents()
+        #expect(emptyContents.isEmpty())
+        #expect(displayList.isEmpty())
+    }
+
+    @Test
+    func testMoveEmptyContents() {
+        let displayList = ORBDisplayList()
+        let contents: any ORBDisplayListContents = displayList.moveContents()
+        #expect(contents.isEmpty())
         #expect(displayList.isEmpty())
     }
 
@@ -94,8 +106,7 @@ struct DisplayListTests {
         displayList.endCGContext()
 
         let contents = displayList.moveContents()
-        #expect(contents != nil)
-        #expect(contents!.isEmpty() == false)
+        #expect(!contents.isEmpty())
     }
     #endif
 }