src/language-js/print/html-binding.js/printHtmlBinding
function printHtmlBinding(path, options, print) {
  const node = path.getValue();

  if (options.__onHtmlBindingRoot && path.getName() === null) {
    options.__onHtmlBindingRoot(node, options);
  }

  if (node.type !== "File") {
    return;
  }

  if (options.__isVueForBindingLeft) {
    return path.call(
      (functionDeclarationPath) => {
        const printed = join(
          [",", line],
          functionDeclarationPath.map(print, "params")
        );

        const { params } = functionDeclarationPath.getValue();
        if (params.length === 1) {
          return printed;
        }

        return ["(", indent([softline, group(printed)]), softline, ")"];
      },
      "program",
      "body",
      0
    );
  }

  if (options.__isVueBindings) {
    return path.call(
      (functionDeclarationPath) =>
        join([",", line], functionDeclarationPath.map(print, "params")),
      "program",
      "body",
      0
    );
  }
}