Function getNodeModulesPackageRoot

packages/vite/src/node/server/sourcemap.ts:25–45

(
  filePath: string,
)

 * Returns `undefined` if the file is not inside node_modules.
 */
export function getNodeModulesPackageRoot(
  filePath: string,
): string | undefined {
  const normalized = normalizePath(filePath)
  const nodeModulesIndex = normalized.lastIndexOf(class="st">'/node_modules/')
  if (nodeModulesIndex === -1) return undefined

  const packageStart = nodeModulesIndex + class="st">'/node_modules/'.length
  const rest = normalized.slice(packageStart)
  const firstSlash = rest.indexOf(class="st">'/')

  let packageName: string
  if (rest.startsWith(class="st">'@')) {
    class="cm">// scoped package: @scope/pkg
    const secondSlash = rest.indexOf(class="st">'/', firstSlash + 1)
    packageName = secondSlash === -1 ? rest : rest.slice(0, secondSlash)
  } else {
    packageName = firstSlash === -1 ? rest : rest.slice(0, firstSlash)
  }
  return normalized.slice(0, packageStart) + packageName
}

class="cm">// Virtual modules should be prefixed with a null byte to avoid a
class="cm">// false positive class="st">"missing source" warning. We also check for certain