Function flattenId

packages/vite/src/node/utils.ts:72–86

(id: string)

const invalidUrlPathCharRE = /[\u0000-\u001F"#$%&*+,:;<=>?[\]^`{|}\u007F]/g
const replaceNestedIdRE = /\s*>\s*/g
export const flattenId = (id: string): string => {
  const flatId = limitFlattenIdLength(
    id
      .replaceAll(/_+/g, '$&__')
      .replaceAll('/', '_')
      .replaceAll('.', '__')
      .replace(replaceNestedIdRE, '_n_')
      // replace any characters that will be replaced by sanitizeFileName
      .replace(
        invalidUrlPathCharRE,
        (c) => '_0' + c.charCodeAt(0).toString(16) + '_',
      ),
  )
  return flatId
}

const FLATTEN_ID_HASH_LENGTH = 8
const FLATTEN_ID_MAX_FILE_LENGTH = 170