Function reconcileChildren

mini-react/src/mini-react.js:156–205

(wipFiber, elements)

      
    
    function reconcileChildren(wipFiber, elements) {
        let index = 0
        let oldFiber = wipFiber.alternate?.child
        let prevSibling = null
    
        while ( index < elements.length || oldFiber != null) {
            const element = elements[index]
            let newFiber = null
    
            const sameType = element?.type == oldFiber?.type
    
            if (sameType) {
                newFiber = {
                    type: oldFiber.type,
                    props: element.props,
                    dom: oldFiber.dom,
                    return: wipFiber,
                    alternate: oldFiber,
                    effectTag: "UPDATE",
                }
            }
            if (element && !sameType) {
                newFiber = {
                    type: element.type,
                    props: element.props,
                    dom: null,
                    return: wipFiber,
                    alternate: null,
                    effectTag: "PLACEMENT",
                }
            }
            if (oldFiber && !sameType) {
                oldFiber.effectTag = "DELETION"
                deletions.push(oldFiber)
            }
    
            if (oldFiber) {
                oldFiber = oldFiber.sibling
            }
    
            if (index === 0) {
                wipFiber.child = newFiber
            } else if (element) {
                prevSibling.sibling = newFiber
            }
    
            prevSibling = newFiber
            index++
        }
    }
    
    function useState(initialState) {
        const currentFiber = wipFiber;