message: Function: show helpful error message when esbuild plugin is not found
diff: @@ -138,6 +138,11 @@ export const NodeHandler: Definition<Bundle> = (opts) => {
  const plugins = bundle.esbuildConfig?.plugins
  ? path.join(opts.root, bundle.esbuildConfig.plugins)
  : undefined;
  + if (plugins && !fs.existsSync(plugins)) {
  + throw new Error(
  + `Cannot find an esbuild plugins file at: ${path.resolve(plugins)}`
  + );
  + }
  return {
  shouldBuild: (files: string[]) => {
  