Function inlineSourceMap

packages/vite/src/node/ssr/fetchModule.ts:123–153

(
  mod: EnvironmentModuleNode,
  result: TransformResult,
  startOffset: number | undefined,
)

)

function inlineSourceMap(
  mod: EnvironmentModuleNode,
  result: TransformResult,
  startOffset: number | undefined,
) {
  const map = result.map
  let code = result.code

  if (
    !map ||
    !('version' in map) ||
    code.includes(MODULE_RUNNER_SOURCEMAPPING_SOURCE)
  )
    return result

  // to reduce the payload size, we only inline vite node source map, because it's also the only one we use
  OTHER_SOURCE_MAP_REGEXP.lastIndex = 0
  if (OTHER_SOURCE_MAP_REGEXP.test(code))
    code = code.replace(OTHER_SOURCE_MAP_REGEXP, '')

  const sourceMap = startOffset
    ? Object.assign({}, map, {
        mappings: ';'.repeat(startOffset) + map.mappings,
      })
    : map
  result.code = `${code.trimEnd()}\n//# sourceURL=${
    mod.id
  }\n${MODULE_RUNNER_SOURCEMAPPING_SOURCE}\n//# ${SOURCEMAPPING_URL}=${genSourceMapUrl(sourceMap)}\n`

  return result
}