Function subTransform

packages/compiler-ssr/src/transforms/ssrTransformComponent.ts:337–372

(
  node: TemplateChildNode,
  options: TransformOptions,
  parentContext: TransformContext,
)

}

function subTransform(
  node: TemplateChildNode,
  options: TransformOptions,
  parentContext: TransformContext,
) {
  const childRoot = createRoot([node])
  const childContext = createTransformContext(childRoot, options)
  // this sub transform is for vnode fallback branch so it should be handled
  // like normal render functions
  childContext.ssr = false
  // inherit parent scope analysis state
  childContext.scopes = { ...parentContext.scopes }
  childContext.identifiers = { ...parentContext.identifiers }
  childContext.imports = parentContext.imports
  // traverse
  traverseNode(childRoot, childContext)
  // merge helpers/components/directives into parent context
  ;(['helpers', 'components', 'directives'] as const).forEach(key => {
    childContext[key].forEach((value: any, helperKey: any) => {
      if (key === 'helpers') {
        const parentCount = parentContext.helpers.get(helperKey)
        if (parentCount === undefined) {
          parentContext.helpers.set(helperKey, value)
        } else {
          parentContext.helpers.set(helperKey, value + parentCount)
        }
      } else {
        ;(parentContext[key] as any).add(value)
      }
    })
  })
  // imports/hoists are not merged because:
  // - imports are only used for asset urls and should be consistent between
  //   node/client branches
  // - hoists are not enabled for the client branch here
}

function clone(v: any): any {
  if (isArray(v)) {