Function render

packages/runtime-core/src/renderer.ts:2419–2444

(vnode, container, namespace)

  let isFlushing = false
  const render: RootRenderFunction = (vnode, container, namespace) => {
    let instance
    if (vnode == null) {
      if (container._vnode) {
        unmount(container._vnode, null, null, true)
        instance = container._vnode.component
      }
    } else {
      patch(
        container._vnode || null,
        vnode,
        container,
        null,
        null,
        null,
        namespace,
      )
    }
    container._vnode = vnode
    if (!isFlushing) {
      isFlushing = true
      flushPreFlushCbs(instance)
      flushPostFlushCbs()
      isFlushing = false
    }
  }

  const internals: RendererInternals = {
    p: patch,