Function finishComponentSetup

packages/runtime-core/src/component.ts:993–1095

(
  instance: ComponentInternalInstance,
  isSSR: boolean,
  skipOptions?: boolean,
)

export const isRuntimeOnly = (): boolean => !compile

export function finishComponentSetup(
  instance: ComponentInternalInstance,
  isSSR: boolean,
  skipOptions?: boolean,
): void {
  const Component = instance.type as ComponentOptions

  if (__COMPAT__) {
    convertLegacyRenderFn(instance)

    if (__DEV__ && Component.compatConfig) {
      validateCompatConfig(Component.compatConfig)
    }
  }

  // template / render function normalization
  // could be already set when returned from setup()
  if (!instance.render) {
    // only do on-the-fly compile if not in SSR - SSR on-the-fly compilation
    // is done by server-renderer
    if (!isSSR && compile && !Component.render) {
      const template =
        (__COMPAT__ &&
          instance.vnode.props &&
          instance.vnode.props['inline-template']) ||
        Component.template ||
        (__FEATURE_OPTIONS_API__ && resolveMergedOptions(instance).template)
      if (template) {
        if (__DEV__) {
          startMeasure(instance, `compile`)
        }
        const { isCustomElement, compilerOptions } = instance.appContext.config
        const { delimiters, compilerOptions: componentCompilerOptions } =
          Component
        const finalCompilerOptions: CompilerOptions = extend(
          extend(
            {
              isCustomElement,
              delimiters,
            },
            compilerOptions,
          ),
          componentCompilerOptions,
        )
        if (__COMPAT__) {
          // pass runtime compat config into the compiler
          finalCompilerOptions.compatConfig = Object.create(globalCompatConfig)
          if (Component.compatConfig) {
            // @ts-expect-error types are not compatible
            extend(finalCompilerOptions.compatConfig, Component.compatConfig)
          }
        }
        Component.render = compile(template, finalCompilerOptions)
        if (__DEV__) {
          endMeasure(instance, `compile`)
        }
      }
    }