feat(ui/system): slottable 개념 도입

packages/ui/system/src/create-polymorphic-component.ts

@@ -3,18 +3,27 @@ import {
   Children,
   type ComponentPropsWithoutRef,
   type ElementType,
+  type ReactElement,
+  type ReactNode,
   type Ref,
   cloneElement,
   createElement,
   isValidElement,
 } from 'react';
 import { forwardRef } from './forward-ref';
+import { Slottable, type SlottableProps } from './slottable';
 import {
   type ComponentWithPolymorphic,
   type JsxElements,
   type PolymorphicProps,
 } from './types';
 
+export function isSlottable(
+  child: ReactNode,
+): child is ReactElement<SlottableProps> {
+  return isValidElement(child) && child.type === Slottable;
+}
+
 export type FavolinkComponent<Component extends ElementType> =
   ComponentWithPolymorphic<Component, object>;
 
@@ -36,6 +45,43 @@ export function createPolymorphicComponent<Component extends ElementType>(
         );
       }
 
+      const childrenArray = Children.toArray(children);
+      const slottable = childrenArray.find(isSlottable);
+
+      if (slottable) {
+        const newElement = slottable.props.children;
+        const newChildren = childrenArray.map((child) => {
+          if (child === slottable) {
+            if (Children.count(newElement) > 1) {
+              return Children.only(null);
+            }
+
+            return isValidElement(newElement)
+              ? ((newElement as ReactElement<{ children: ReactNode }>).props
+                  .children as ReactNode)
+              : null;
+          } else {
+            return child;
+          }
+        });
+
+        return isValidElement(newElement)
+          ? cloneElement(
+              newElement as ReactElement,
+              {
+                ...mergeProps(restProps, newElement.props),
+                ref: ref
+                  ? composeRefs(
+                      ref,
+                      (newElement as ReactElement & { ref: Ref<any> }).ref,
+                    )
+                  : (newElement as ReactElement & { ref: Ref<any> }).ref,
+              },
+              newChildren,
+            )
+          : null;
+      }
+
       const onlyChild = Children.only(children);
 
       return isValidElement(onlyChild)

packages/ui/system/src/index.ts

@@ -4,4 +4,5 @@ export * from './create-polymorphic-component';
 export * from './create-raw-style-props';
 export * from './factory';
 export * from './forward-ref';
+export * from './slottable';
 export * from './types';

packages/ui/system/src/slottable.tsx

@@ -0,0 +1,11 @@
+import { type ReactNode } from 'react';
+
+export type SlottableProps = {
+  children: ReactNode;
+};
+
+export function Slottable(props: SlottableProps) {
+  const { children } = props;
+
+  return children;
+}