Function createComponentInstance

packages/runtime-core/src/component.ts:614–716

(
  vnode: VNode,
  parent: ComponentInternalInstance | null,
  suspense: SuspenseBoundary | null,
)

let uid = 0

export function createComponentInstance(
  vnode: VNode,
  parent: ComponentInternalInstance | null,
  suspense: SuspenseBoundary | null,
): ComponentInternalInstance {
  const type = vnode.type as ConcreteComponent
  // inherit parent app context - or - if root, adopt from root vnode
  const appContext =
    (parent ? parent.appContext : vnode.appContext) || emptyAppContext

  const instance: ComponentInternalInstance = {
    uid: uid++,
    vnode,
    type,
    parent,
    appContext,
    root: null!, // to be immediately set
    next: null,
    subTree: null!, // will be set synchronously right after creation
    effect: null!,
    update: null!, // will be set synchronously right after creation
    job: null!,
    scope: new EffectScope(true /* detached */),
    render: null,
    proxy: null,
    exposed: null,
    exposeProxy: null,
    withProxy: null,

    provides: parent ? parent.provides : Object.create(appContext.provides),
    ids: parent ? parent.ids : ['', 0, 0],
    accessCache: null!,
    renderCache: [],

    // local resolved assets
    components: null,
    directives: null,

    // resolved props and emits options
    propsOptions: normalizePropsOptions(type, appContext),
    emitsOptions: normalizeEmitsOptions(type, appContext),

    // emit
    emit: null!, // to be set immediately
    emitted: null,

    // props default value
    propsDefaults: EMPTY_OBJ,

    // inheritAttrs
    inheritAttrs: type.inheritAttrs,

    // state
    ctx: EMPTY_OBJ,
    data: EMPTY_OBJ,
    props: EMPTY_OBJ,
    attrs: EMPTY_OBJ,
    slots: EMPTY_OBJ,