Function buildProps

packages/compiler-core/src/transforms/transformElement.ts:374–831

(
  node: ElementNode,
  context: TransformContext,
  props: ElementNode['props'] | undefined = node.props,
  isComponent: boolean,
  isDynamicComponent: boolean,
  ssr = false,
)

export type PropsExpression = ObjectExpression | CallExpression | ExpressionNode

export function buildProps(
  node: ElementNode,
  context: TransformContext,
  props: ElementNode['props'] | undefined = node.props,
  isComponent: boolean,
  isDynamicComponent: boolean,
  ssr = false,
): {
  props: PropsExpression | undefined
  directives: DirectiveNode[]
  patchFlag: number
  dynamicPropNames: string[]
  shouldUseBlock: boolean
} {
  const { tag, loc: elementLoc, children } = node
  let properties: ObjectExpression['properties'] = []
  const mergeArgs: PropsExpression[] = []
  const runtimeDirectives: DirectiveNode[] = []
  const hasChildren = children.length > 0
  let shouldUseBlock = false

  // patchFlag analysis
  let patchFlag = 0
  let hasRef = false
  let hasClassBinding = false
  let hasStyleBinding = false
  let hasHydrationEventBinding = false
  let hasDynamicKeys = false
  let hasVnodeHook = false
  const dynamicPropNames: string[] = []

  const pushMergeArg = (arg?: PropsExpression) => {
    if (properties.length) {
      mergeArgs.push(
        createObjectExpression(dedupeProperties(properties), elementLoc),
      )
      properties = []
    }
    if (arg) mergeArgs.push(arg)
  }

  // mark template ref on v-for
  const pushRefVForMarker = () => {
    if (context.scopes.vFor > 0) {
      properties.push(
        createObjectProperty(
          createSimpleExpression('ref_for', true),
          createSimpleExpression('true'),
        ),
      )
    }
  }

  const analyzePatchFlag = ({ key, value }: Property) => {
    if (isStaticExp(key)) {
      const name = key.content
      const isEventHandler = isOn(name)
      if (