wrapWithTopLevelDefinitions() — react Function Reference

Source Code

scripts/rollup/wrappers.js lines 507–563

function wrapWithTopLevelDefinitions(
  source,
  bundleType,
  globalName,
  filename,
  moduleType,
  wrapWithModuleBoundaries
) {
  if (wrapWithModuleBoundaries) {
    switch (bundleType) {
      case NODE_DEV:
      case NODE_PROFILING:
      case FB_WWW_DEV:
      case FB_WWW_PROFILING:
      case RN_OSS_DEV:
      case RN_OSS_PROFILING:
      case RN_FB_DEV:
      case RN_FB_PROFILING:
        // Remove the 'use strict' directive from source.
        // The module start wrapper will add its own.
        // This directive is only meaningful when it is the first statement in a file or function.
        source = source.replace(USE_STRICT_HEADER_REGEX, '');

        // Certain DEV and Profiling bundles should self-register their own module boundaries with DevTools.
        // This allows the Timeline to de-emphasize (dim) internal stack frames.
        source = wrapWithRegisterInternalModule(source);
        break;
    }
  }

  if (bundleType === BROWSER_SCRIPT) {
    // Bundles of type BROWSER_SCRIPT get sent straight to the browser without
    // additional processing. So we should exclude any extra wrapper comments.
    return source;
  }

  if (moduleType === RECONCILER) {
    // Standalone reconciler is only used by third-party renderers.
    // It is handled separately.
    const wrapper = reconcilerWrappers[bundleType];
    if (typeof wrapper !== 'function') {
      throw new Error(
        `Unsupported build type for the reconciler package: ${bundleType}.`
      );
    }

    return wrapper(source, globalName, filename, moduleType);
  }

  // All the other packages.
  const wrapper = topLevelDefinitionWrappers[bundleType];
  if (typeof wrapper !== 'function') {
    throw new Error(`Unsupported build type: ${bundleType}.`);
  }

  return wrapper(source, globalName, filename, moduleType);
}