fs

POSIX and Windows path types — IsAbsolute, ExtensionOf, NormalizePath.

import type {
  PosixAbsolutePath, PosixRelativePath, PosixPath,
  WindowsAbsolutePath, WindowsPath,
  IsAbsolute,
  ExtensionOf, BasenameOf, DirnameOf, StemOf,
  JoinPaths, NormalizePath,
} from '@gentleduck/ttest/fs'

POSIX path types operate on forward-slash paths. Normalize Windows backslashes at runtime before piping through.

Path unions

type PosixAbsolutePath   = `/${string}`
type PosixRelativePath   = `${'' | './' | '../'}${string}`
type PosixPath           = PosixAbsolutePath | PosixRelativePath

type WindowsAbsolutePath = `${Uppercase<string>}:\\${string}` | `\\\\${string}`
type WindowsPath         = WindowsAbsolutePath | `${string}\\${string}`

IsAbsolute

type IsAbsolute<P extends string>

true if P begins with / (POSIX) or a drive letter / UNC (Windows).

type a = IsAbsolute<'/usr/bin'>    // true
type b = IsAbsolute<'./foo'>       // false
type c = IsAbsolute<'C:\\Users'>   // true

ExtensionOf

type ExtensionOf<P extends string>

Extract the file extension including the leading dot, or '' if none.

type a = ExtensionOf<'foo.ts'>      // '.ts'
type b = ExtensionOf<'index.d.ts'>  // '.ts'
type c = ExtensionOf<'Makefile'>    // ''

BasenameOf

type BasenameOf<P extends string>

Final path segment.

type a = BasenameOf<'/a/b/c.txt'>  // 'c.txt'
type b = BasenameOf<'foo.ts'>      // 'foo.ts'

DirnameOf

type DirnameOf<P extends string>

Directory portion of a path.

type a = DirnameOf<'/a/b/c.txt'>  // '/a/b'
type b = DirnameOf<'foo.ts'>      // ''

StemOf

type StemOf<P extends string>

Basename without the final extension.

type a = StemOf<'foo.ts'>      // 'foo'
type b = StemOf<'index.d.ts'>  // 'index.d'
type c = StemOf<'Makefile'>    // 'Makefile'

JoinPaths

type JoinPaths<A extends string, B extends string>

Join two path segments with a /.

type x = JoinPaths<'a/b', 'c/d'>  // 'a/b/c/d'

NormalizePath

type NormalizePath<P extends string>

Remove ./ segments and collapse ...

type x = NormalizePath<'/a/./b/../c'>  // '/a/c'