text: const virtualFile = '@virtual-file'
  const virtualId = '\0' + virtualFile
  
  const customVirtualFile = '@custom-virtual-file'
  
  module.exports = {
    resolve: {
      extensions: ['.mjs', '.js', '.es', '.ts'],
      mainFields: ['custom', 'module'],
      conditions: ['custom']
    },
    plugins: [
      {
        name: 'virtual-module',
        resolveId(id) {
          if (id === virtualFile) {
            return virtualId
          }
        },
        load(id) {
          if (id === virtualId) {
            return `export const msg = "[success] from conventional virtual file"`
          }
        }
      },
      {
        name: 'custom-resolve',
        resolveId(id) {
          if (id === customVirtualFile) {
            return id
          }
        },
        load(id) {
          if (id === customVirtualFile) {
            return `export const msg = "[success] from custom virtual file"`
          }
        }
      }
    ]
  }
  