glob (#268)

packages/glob/src/glob.ts

@@ -0,0 +1,183 @@
+import * as core from '@actions/core'
+import * as fs from 'fs'
+import * as path from 'path'
+import * as patternHelper from './internal-pattern-helper'
+import {IGlobOptions} from './internal-glob-options'
+import {MatchKind} from './internal-match-kind'
+import {Pattern} from './internal-pattern'
+import {SearchState} from './internal-search-state'
+
+export {IGlobOptions}
+
+/**
+ * Returns files and directories matching the specified glob pattern.
+ *
+ * Order of the results is not guaranteed.
+ */
+export async function glob(
+  pattern: string,
+  options?: IGlobOptions
+): Promise<string[]> {
+  const result: string[] = []
+  for await (const itemPath of globGenerator(pattern, options)) {
+    result.push(itemPath)
+  }
+  return result
+}
+
+/**
+ * Returns files and directories matching the specified glob pattern.
+ *
+ * Order of the results is not guaranteed.
+ */
+export async function* globGenerator(
+  pattern: string,
+  options?: IGlobOptions
+): AsyncGenerator<string, void> {
+  // Set defaults options
+  options = patternHelper.getOptions(options)
+
+  // Parse patterns
+  const patterns: Pattern[] = patternHelper.parse([pattern], options)
+
+  // Push the search paths
+  const stack: SearchState[] = []
+  for (const searchPath of patternHelper.getSearchPaths(patterns)) {
+    core.debug(`Search path '${searchPath}'`)
+
+    // Exists?
+    try {
+      // Intentionally using lstat. Detection for broken symlink
+      // will be performed later (if following symlinks).
+      await fs.promises.lstat(searchPath)
+    } catch (err) {
+      if (err.code === 'ENOENT') {
+        continue
+      }
+      throw err
+    }
+
+    stack.unshift(new SearchState(searchPath, 1))
+  }
+
+  // Search
+  const traversalChain: string[] = [] // used to detect cycles
+  while (stack.length) {
+    // Pop
+    const item = stack.pop() as SearchState
+
+    // Match?
+    const match = patternHelper.match(patterns, item.path)
+    const partialMatch =
+      !!match || patternHelper.partialMatch(patterns, item.path)
+    if (!match && !partialMatch) {
+      continue
+    }
+
+    // Stat
+    const stats: fs.Stats | undefined = await stat(
+      item,
+      options,
+      traversalChain
+    )
+
+    // Broken symlink, or symlink cycle detected, or no longer exists
+    if (!stats) {
+      continue
+    }
+
+    // Directory
+    if (stats.isDirectory()) {
+      // Matched
+      if (match & MatchKind.Directory) {
+        yield item.path
+      }
+      // Descend?
+      else if (!partialMatch) {
+        continue
+      }
+
+      // Push the child items in reverse
+      const childLevel = item.level + 1
+      const childItems = (await fs.promises.readdir(item.path)).map(
+        x => new SearchState(path.join(item.path, x), childLevel)
+      )
+      stack.push(...childItems.reverse())
+    }
+    // File
+    else if (match & MatchKind.File) {
+      yield item.path
+    }
+  }
+}
+
+/**
+ * Returns the search path preceeding the first segment that contains a pattern.
+ *
+ * For example, '/foo/bar*' returns '/foo'.
+ */
+export function getSearchPath(pattern: string): string {
+  const patterns: Pattern[] = patternHelper.parse(
+    [pattern],
+    patternHelper.getOptions()
+  )
+  const searchPaths: string[] = patternHelper.getSearchPaths(patterns)
+  return searchPaths.length > 0 ? searchPaths[0] : ''
+}
+
+async function stat(
+  item: SearchState,
+  options: IGlobOptions,
+  traversalChain: string[]
+): Promise<fs.Stats | undefined> {
+  // Note:
+  // `stat` returns info about the target of a symlink (or symlink chain)
+  // `lstat` returns info about a symlink itself
+  let stats: fs.Stats
+  if (options.followSymbolicLinks) {
+    try {
+      // Use `stat` (following symlinks)
+      stats = await fs.promises.stat(item.path)
+    } catch (err) {
+      if (err.code === 'ENOENT') {
+        if (options.omitBrokenSymbolicLinks) {
+          core.debug(`Broken symlink '${item.path}'`)
+          return undefined
+        }
+
+        throw new Error(
+          `No information found for the path '${item.path}'. This may indicate a broken symbolic link.`
+        )
+      }
+
+      throw err
+    }
+  } else {
+    // Use `lstat` (not following symlinks)
+    stats = await fs.promises.lstat(item.path)
+  }
+
+  // Note, isDirectory() returns false for the lstat of a symlink
+  if (stats.isDirectory() && options.followSymbolicLinks) {
+    // Get the realpath
+    const realPath: string = await fs.promises.realpath(item.path)
+
+    // Fixup the traversal chain to match the item level
+    while (traversalChain.length >= item.level) {
+      traversalChain.pop()
+    }
+
+    // Test for a cycle
+    if (traversalChain.some((x: string) => x === realPath)) {
+      core.debug(
+        `Symlink cycle detected for path '${item.path}' and realpath '${realPath}'`
+      )
+      return undefined
+    }
+
+    // Update the traversal chain
+    traversalChain.push(realPath)
+  }
+
+  return stats
+}

packages/glob/src/internal-glob-options.ts

@@ -0,0 +1,28 @@
+export interface IGlobOptions {
+  /**
+   * Indicates whether to follow symbolic links. Generally should be true
+   * unless deleting files.
+   *
+   * @default true
+   */
+  followSymbolicLinks?: boolean
+
+  /**
+   * Indicates whether directories that match a glob pattern, should implicitly
+   * cause all descendant paths to be matched.
+   *
+   * For example, given the directory `my-dir`, the following glob patterns
+   * would produce the same results: `my-dir/**`, `my-dir/`, `my-dir`
+   *
+   * @default true
+   */
+  implicitDescendants?: boolean
+
+  /**
+   * Indicates whether broken symbolic should be ignored and omitted from the
+   * result set. Otherwise an error will be thrown.
+   *
+   * @default true
+   */
+  omitBrokenSymbolicLinks?: boolean
+}

packages/glob/src/internal-match-kind.ts

@@ -0,0 +1,16 @@
+/**
+ * Indicates whether a pattern matches a path
+ */
+export enum MatchKind {
+  /** Not matched */
+  None = 0,
+
+  /** Matched if the path is a directory */
+  Directory = 1,
+
+  /** Matched if the path is a regular file */
+  File = 2,
+
+  /** Matched */
+  All = Directory | File
+}

packages/glob/src/internal-path-helper.ts

@@ -0,0 +1,206 @@
+import * as assert from 'assert'
+import * as path from 'path'
+
+const IS_WINDOWS = process.platform === 'win32'
+
+/**
+ * Similar to path.dirname except normalizes the path separators and slightly better handling for Windows UNC paths.
+ *
+ * For example, on Linux/macOS:
+ * - `/               => /`
+ * - `/hello          => /`
+ *
+ * For example, on Windows:
+ * - `C:\             => C:\`
+ * - `C:\hello        => C:\`
+ * - `C:              => C:`
+ * - `C:hello         => C:`
+ * - `\               => \`
+ * - `\hello          => \`
+ * - `\\hello         => \\hello`
+ * - `\\hello\world   => \\hello\world`
+ */
+export function dirname(p: string): string {
+  // Normalize slashes and trim unnecessary trailing slash
+  p = safeTrimTrailingSeparator(p)
+
+  // Windows UNC root, e.g. \\hello or \\hello\world
+  if (IS_WINDOWS && /^\\\\[^\\]+(\\[^\\]+)?$/.test(p)) {
+    return p
+  }
+
+  // Get dirname
+  let result = path.dirname(p)
+
+  // Trim trailing slash for Windows UNC root, e.g. \\hello\world\
+  if (IS_WINDOWS && /^\\\\[^\\]+\\[^\\]+\\$/.test(result)) {
+    result = safeTrimTrailingSeparator(result)
+  }
+
+  return result
+}
+
+/**
+ * Roots the path if not already rooted. On Windows, relative roots like `\`
+ * or `C:` are expanded based on the current working directory.
+ */
+export function ensureAbsoluteRoot(root: string, itemPath: string): string {
+  assert(root, `ensureAbsoluteRoot parameter 'root' must not be empty`)
+  assert(itemPath, `ensureAbsoluteRoot parameter 'itemPath' must not be empty`)
+
+  // Already rooted
+  if (hasAbsoluteRoot(itemPath)) {
+    return itemPath
+  }
+
+  // Windows
+  if (IS_WINDOWS) {
+    // Check for itemPath like C: or C:foo
+    if (itemPath.match(/^[A-Z]:[^\\/]|^[A-Z]:$/i)) {
+      let cwd = process.cwd()
+      assert(
+        cwd.match(/^[A-Z]:\\/i),
+        `Expected current directory to start with an absolute drive root. Actual '${cwd}'`
+      )
+
+      // Drive letter matches cwd? Expand to cwd
+      if (itemPath[0].toUpperCase() === cwd[0].toUpperCase()) {
+        // Drive only, e.g. C:
+        if (itemPath.length === 2) {
+          // Preserve specified drive letter case (upper or lower)
+          return `${itemPath[0]}:\\${cwd.substr(3)}`
+        }
+        // Drive + path, e.g. C:foo
+        else {
+          if (!cwd.endsWith('\\')) {
+            cwd += '\\'
+          }
+          // Preserve specified drive letter case (upper or lower)
+          return `${itemPath[0]}:\\${cwd.substr(3)}${itemPath.substr(2)}`
+        }
+      }
+      // Different drive
+      else {
+        return `${itemPath[0]}:\\${itemPath.substr(2)}`
+      }
+    }
+    // Check for itemPath like \ or \foo
+    else if (normalizeSeparators(itemPath).match(/^\\$|^\\[^\\]/)) {
+      const cwd = process.cwd()
+      assert(
+        cwd.match(/^[A-Z]:\\/i),
+        `Expected current directory to start with an absolute drive root. Actual '${cwd}'`
+      )
+
+      return `${cwd[0]}:\\${itemPath.substr(1)}`
+    }
+  }
+
+  assert(
+    hasAbsoluteRoot(root),
+    `ensureAbsoluteRoot parameter 'root' must have an absolute root`
+  )
+
+  // Otherwise ensure root ends with a separator
+  if (root.endsWith('/') || (IS_WINDOWS && root.endsWith('\\'))) {
+    // Intentionally empty
+  } else {
+    // Append separator
+    root += path.sep
+  }
+
+  return root + itemPath
+}
+
+/**
+ * On Linux/macOS, true if path starts with `/`. On Windows, true for paths like:
+ * `\\hello\share` and `C:\hello` (and using alternate separator).
+ */
+export function hasAbsoluteRoot(itemPath: string): boolean {
+  assert(itemPath, `hasAbsoluteRoot parameter 'itemPath' must not be empty`)
+
+  // Normalize separators
+  itemPath = normalizeSeparators(itemPath)
+
+  // Windows
+  if (IS_WINDOWS) {
+    // E.g. \\hello\share or C:\hello
+    return itemPath.startsWith('\\\\') || /^[A-Z]:\\/i.test(itemPath)
+  }
+
+  // E.g. /hello
+  return itemPath.startsWith('/')
+}
+
+/**
+ * On Linux/macOS, true if path starts with `/`. On Windows, true for paths like:
+ * `\`, `\hello`, `\\hello\share`, `C:`, and `C:\hello` (and using alternate separator).
+ */
+export function hasRoot(itemPath: string): boolean {
+  assert(itemPath, `isRooted parameter 'itemPath' must not be empty`)
+
+  // Normalize separators
+  itemPath = normalizeSeparators(itemPath)
+
+  // Windows
+  if (IS_WINDOWS) {
+    // E.g. \ or \hello or \\hello
+    // E.g. C: or C:\hello
+    return itemPath.startsWith('\\') || /^[A-Z]:/i.test(itemPath)
+  }
+
+  // E.g. /hello
+  return itemPath.startsWith('/')
+}
+
+/**
+ * Removes redundant slashes and converts `/` to `\` on Windows
+ */
+export function normalizeSeparators(p: string): string {
+  p = p || ''
+
+  // Windows
+  if (IS_WINDOWS) {
+    // Convert slashes on Windows
+    p = p.replace(/\//g, '\\')
+
+    // Remove redundant slashes
+    const isUnc = /^\\\\+[^\\]/.test(p) // e.g. \\hello
+    return (isUnc ? '\\' : '') + p.replace(/\\\\+/g, '\\') // preserve leading \\ for UNC
+  }
+
+  // Remove redundant slashes
+  return p.replace(/\/\/+/g, '/')
+}
+
+/**
+ * Normalizes the path separators and trims the trailing separator (when safe).
+ * For example, `/foo/ => /foo` but `/ => /`
+ */
+export function safeTrimTrailingSeparator(p: string): string {
+  // Short-circuit if empty
+  if (!p) {
+    return ''
+  }
+
+  // Normalize separators
+  p = normalizeSeparators(p)
+
+  // No trailing slash
+  if (!p.endsWith(path.sep)) {
+    return p
+  }
+
+  // Check '/' on Linux/macOS and '\' on Windows
+  if (p === path.sep) {
+    return p
+  }
+
+  // On Windows check if drive root. E.g. C:\
+  if (IS_WINDOWS && /^[A-Z]:\\$/i.test(p)) {
+    return p
+  }
+
+  // Otherwise trim trailing slash
+  return p.substr(0, p.length - 1)
+}

packages/glob/src/internal-path.ts

@@ -0,0 +1,113 @@
+import * as assert from 'assert'
+import * as path from 'path'
+import * as pathHelper from './internal-path-helper'
+
+const IS_WINDOWS = process.platform === 'win32'
+
+/**
+ * Helper class for parsing paths into segments
+ */
+export class Path {
+  segments: string[] = []
+
+  /**
+   * Constructs a Path
+   * @param itemPath Path or array of segments
+   */
+  constructor(itemPath: string | string[]) {
+    // String
+    if (typeof itemPath === 'string') {
+      assert(itemPath, `Parameter 'itemPath' must not be empty`)
+
+      // Normalize slashes and trim unnecessary trailing slash
+      itemPath = pathHelper.safeTrimTrailingSeparator(itemPath)
+
+      // Not rooted
+      if (!pathHelper.hasRoot(itemPath)) {
+        this.segments = itemPath.split(path.sep)
+      }
+      // Rooted
+      else {
+        // Add all segments, while not at the root
+        let remaining = itemPath
+        let dir = pathHelper.dirname(remaining)
+        while (dir !== remaining) {
+          // Add the segment
+          const basename = path.basename(remaining)
+          this.segments.unshift(basename)
+
+          // Truncate the last segment
+          remaining = dir
+          dir = pathHelper.dirname(remaining)
+        }
+
+        // Remainder is the root
+        this.segments.unshift(remaining)
+      }
+    }
+    // Array
+    else {
+      // Must not be empty
+      assert(
+        itemPath.length > 0,
+        `Parameter 'itemPath' must not be an empty array`
+      )
+
+      // Each segment
+      for (let i = 0; i < itemPath.length; i++) {
+        let segment = itemPath[i]
+
+        // Must not be empty
+        assert(
+          segment,
+          `Parameter 'itemPath' must not contain any empty segments`
+        )
+
+        // Normalize slashes
+        segment = pathHelper.normalizeSeparators(itemPath[i])
+
+        // Root segment
+        if (i === 0 && pathHelper.hasRoot(segment)) {
+          segment = pathHelper.safeTrimTrailingSeparator(segment)
+          assert(
+            segment === pathHelper.dirname(segment),
+            `Parameter 'itemPath' root segment contains information for multiple segments`
+          )
+          this.segments.push(segment)
+        }
+        // All other segments
+        else {
+          // Must not contain slash
+          assert(
+            !segment.includes(path.sep),
+            `Parameter 'itemPath' contains unexpected path separators`
+          )
+          this.segments.push(segment)
+        }
+      }
+    }
+  }
+
+  /**
+   * Converts the path to it's string representation
+   */
+  toString(): string {
+    // First segment
+    let result = this.segments[0]
+
+    // All others
+    let skipSlash =
+      result.endsWith(path.sep) || (IS_WINDOWS && /^[A-Z]:$/i.test(result))
+    for (let i = 1; i < this.segments.length; i++) {
+      if (skipSlash) {
+        skipSlash = false
+      } else {
+        result += path.sep
+      }
+
+      result += this.segments[i]
+    }
+
+    return result
+  }
+}

packages/glob/src/internal-pattern-helper.ts

@@ -0,0 +1,143 @@
+import * as core from '@actions/core'
+import * as pathHelper from './internal-path-helper'
+import {IGlobOptions} from './internal-glob-options'
+import {MatchKind} from './internal-match-kind'
+import {Pattern} from './internal-pattern'
+
+const IS_WINDOWS = process.platform === 'win32'
+
+/**
+ * Returns a copy with defaults filled in
+ */
+export function getOptions(copy?: IGlobOptions): IGlobOptions {
+  const result: IGlobOptions = {
+    followSymbolicLinks: true,
+    implicitDescendants: true,
+    omitBrokenSymbolicLinks: true
+  }
+
+  if (copy) {
+    if (typeof copy.followSymbolicLinks === 'boolean') {
+      result.followSymbolicLinks = copy.followSymbolicLinks
+      core.debug(`followSymbolicLinks '${result.followSymbolicLinks}'`)
+    }
+
+    if (typeof copy.implicitDescendants === 'boolean') {
+      result.implicitDescendants = copy.implicitDescendants
+      core.debug(`implicitDescendants '${result.implicitDescendants}'`)
+    }
+
+    if (typeof copy.omitBrokenSymbolicLinks === 'boolean') {
+      result.omitBrokenSymbolicLinks = copy.omitBrokenSymbolicLinks
+      core.debug(`omitBrokenSymbolicLinks '${result.omitBrokenSymbolicLinks}'`)
+    }
+  }
+
+  return result
+}
+
+/**
+ * Given an array of patterns, returns an array of paths to search.
+ * Duplicates and paths under other included paths are filtered out.
+ */
+export function getSearchPaths(patterns: Pattern[]): string[] {
+  // Ignore negate patterns
+  patterns = patterns.filter(x => !x.negate)
+
+  // Create a map of all search paths
+  const searchPathMap: {[key: string]: string} = {}
+  for (const pattern of patterns) {
+    const key = IS_WINDOWS
+      ? pattern.searchPath.toUpperCase()
+      : pattern.searchPath
+    searchPathMap[key] = 'candidate'
+  }
+
+  const result: string[] = []
+
+  for (const pattern of patterns) {
+    // Check if already included
+    const key = IS_WINDOWS
+      ? pattern.searchPath.toUpperCase()
+      : pattern.searchPath
+    if (searchPathMap[key] === 'included') {
+      continue
+    }
+
+    // Check for an ancestor search path
+    let foundAncestor = false
+    let tempKey = key
+    let parent = pathHelper.dirname(tempKey)
+    while (parent !== tempKey) {
+      if (searchPathMap[parent]) {
+        foundAncestor = true
+        break
+      }
+
+      tempKey = parent
+      parent = pathHelper.dirname(tempKey)
+    }
+
+    // Include the search pattern in the result
+    if (!foundAncestor) {
+      result.push(pattern.searchPath)
+      searchPathMap[key] = 'included'
+    }
+  }
+
+  return result
+}
+
+/**
+ * Matches the patterns against the path
+ */
+export function match(patterns: Pattern[], itemPath: string): MatchKind {
+  let result: MatchKind = MatchKind.None
+
+  for (const pattern of patterns) {
+    if (pattern.negate) {
+      result &= ~pattern.match(itemPath)
+    } else {
+      result |= pattern.match(itemPath)
+    }
+  }
+
+  return result
+}
+
+/**
+ * Parses the pattern strings into Pattern objects
+ */
+export function parse(patterns: string[], options: IGlobOptions): Pattern[] {
+  const result: Pattern[] = []
+
+  for (const patternString of patterns.map(x => x.trim())) {
+    // Skip empty or comment
+    if (!patternString || patternString.startsWith('#')) {
+      continue
+    }
+
+    // Push
+    const pattern = new Pattern(patternString)
+    result.push(pattern)
+
+    // Implicit descendants?
+    if (
+      options.implicitDescendants &&
+      (pattern.trailingSeparator ||
+        pattern.segments[pattern.segments.length - 1] !== '**')
+    ) {
+      // Push
+      result.push(new Pattern(pattern.negate, pattern.segments.concat('**')))
+    }
+  }
+
+  return result
+}
+
+/**
+ * Checks whether to descend further into the directory
+ */
+export function partialMatch(patterns: Pattern[], itemPath: string): boolean {
+  return patterns.some(x => !x.negate && x.partialMatch(itemPath))
+}

packages/glob/src/internal-pattern.ts

@@ -0,0 +1,321 @@
+import * as assert from 'assert'
+import * as os from 'os'
+import * as path from 'path'
+import * as pathHelper from './internal-path-helper'
+import {Minimatch, IMinimatch, IOptions as IMinimatchOptions} from 'minimatch'
+import {MatchKind} from './internal-match-kind'
+import {Path} from './internal-path'
+
+const IS_WINDOWS = process.platform === 'win32'
+
+export class Pattern {
+  /**
+   * Indicates whether matches should be excluded from the result set
+   */
+  readonly negate: boolean = false
+
+  /**
+   * The directory to search. The literal path prior to the first glob segment.
+   */
+  readonly searchPath: string
+
+  /**
+   * The path/pattern segments. Note, only the first segment (the root directory)
+   * may contain a directory separator charactor. Use the trailingSeparator field
+   * to determine whether the pattern ended with a trailing slash.
+   */
+  readonly segments: string[]
+
+  /**
+   * Indicates the pattern should only match directories, not regular files.
+   */
+  readonly trailingSeparator: boolean
+
+  /**
+   * The Minimatch object used for matching
+   */
+  private readonly minimatch: IMinimatch
+
+  /**
+   * Used to workaround a limitation with Minimatch when determining a partial
+   * match and the path is a root directory. For example, when the pattern is
+   * `/foo/**` or `C:\foo\**` and the path is `/` or `C:\`.
+   */
+  private readonly rootRegExp: RegExp
+
+  /* eslint-disable no-dupe-class-members */
+  // Disable no-dupe-class-members due to false positive for method overload
+  // https://github.com/typescript-eslint/typescript-eslint/issues/291
+
+  constructor(pattern: string)
+  constructor(negate: boolean, segments: string[])
+  constructor(patternOrNegate: string | boolean, segments?: string[]) {
+    // Pattern overload
+    let pattern: string
+    if (typeof patternOrNegate === 'string') {
+      pattern = patternOrNegate.trim()
+    }
+    // Segments overload
+    else {
+      // Convert to pattern
+      segments = segments || []
+      assert(segments.length, `Parameter 'segments' must not empty`)
+      const root = Pattern.getLiteral(segments[0])
+      assert(
+        root && pathHelper.hasAbsoluteRoot(root),
+        `Parameter 'segments' first element must be a root path`
+      )
+      pattern = new Path(segments).toString().trim()
+      if (patternOrNegate) {
+        pattern = `!${pattern}`
+      }
+    }
+
+    // Negate
+    while (pattern.startsWith('!')) {
+      this.negate = !this.negate
+      pattern = pattern.substr(1).trim()
+    }
+
+    // Normalize slashes and ensures absolute root
+    pattern = Pattern.fixupPattern(pattern)
+
+    // Segments
+    this.segments = new Path(pattern).segments
+
+    // Trailing slash indicates the pattern should only match directories, not regular files
+    this.trailingSeparator = pathHelper
+      .normalizeSeparators(pattern)
+      .endsWith(path.sep)
+    pattern = pathHelper.safeTrimTrailingSeparator(pattern)
+
+    // Search path (literal path prior to the first glob segment)
+    let foundGlob = false
+    const searchSegments = this.segments
+      .map(x => Pattern.getLiteral(x))
+      .filter(x => !foundGlob && !(foundGlob = x === ''))
+    this.searchPath = new Path(searchSegments).toString()
+
+    // Root RegExp (required when determining partial match)
+    this.rootRegExp = new RegExp(
+      Pattern.regExpEscape(searchSegments[0]),
+      IS_WINDOWS ? 'i' : ''
+    )
+
+    // Create minimatch
+    const minimatchOptions: IMinimatchOptions = {
+      dot: true,
+      nobrace: true,
+      nocase: IS_WINDOWS,
+      nocomment: true,
+      noext: true,
+      nonegate: true
+    }
+    pattern = IS_WINDOWS ? pattern.replace(/\\/g, '/') : pattern
+    this.minimatch = new Minimatch(pattern, minimatchOptions)
+  }
+
+  /**
+   * Matches the pattern against the specified path
+   */
+  match(itemPath: string): MatchKind {
+    // Last segment is globstar?
+    if (this.segments[this.segments.length - 1] === '**') {
+      // Normalize slashes
+      itemPath = pathHelper.normalizeSeparators(itemPath)
+
+      // Append a trailing slash. Otherwise Minimatch will not match the directory immediately
+      // preceeding the globstar. For example, given the pattern `/foo/**`, Minimatch returns
+      // false for `/foo` but returns true for `/foo/`. Append a trailing slash to handle that quirk.
+      if (!itemPath.endsWith(path.sep)) {
+        // Note, this is safe because the constructor ensures the pattern has an absolute root.
+        // For example, formats like C: and C:foo on Windows are resolved to an aboslute root.
+        itemPath = `${itemPath}${path.sep}`
+      }
+    } else {
+      // Normalize slashes and trim unnecessary trailing slash
+      itemPath = pathHelper.safeTrimTrailingSeparator(itemPath)
+    }
+
+    // Match
+    if (this.minimatch.match(itemPath)) {
+      return this.trailingSeparator ? MatchKind.Directory : MatchKind.All
+    }
+
+    return MatchKind.None
+  }
+
+  /**
+   * Indicates whether the pattern may match descendants of the specified path
+   */
+  partialMatch(itemPath: string): boolean {
+    // Normalize slashes and trim unnecessary trailing slash
+    itemPath = pathHelper.safeTrimTrailingSeparator(itemPath)
+
+    // matchOne does not handle root path correctly
+    if (pathHelper.dirname(itemPath) === itemPath) {
+      return this.rootRegExp.test(itemPath)
+    }
+
+    return this.minimatch.matchOne(
+      itemPath.split(IS_WINDOWS ? /\\+/ : /\/+/),
+      this.minimatch.set[0],
+      true
+    )
+  }
+
+  /**
+   * Escapes glob patterns within a path
+   */
+  static globEscape(s: string): string {
+    return (IS_WINDOWS ? s : s.replace(/\\/g, '\\\\')) // escape '\' on Linux/macOS
+      .replace(/(\[)(?=[^/]+\])/g, '[[]') // escape '[' when ']' follows within the path segment
+      .replace(/\?/g, '[?]') // escape '?'
+      .replace(/\*/g, '[*]') // escape '*'
+  }
+
+  /**
+   * Normalizes slashes and ensures absolute root
+   */
+  private static fixupPattern(pattern: string): string {
+    // Empty
+    assert(pattern, 'pattern cannot be empty')
+
+    // Must not contain `.` segment, unless first segment
+    // Must not contain `..` segment
+    const literalSegments = new Path(pattern).segments.map(x =>
+      Pattern.getLiteral(x)
+    )
+    assert(
+      literalSegments.every((x, i) => (x !== '.' || i === 0) && x !== '..'),
+      `Invalid pattern '${pattern}'. Relative pathing '.' and '..' is not allowed.`
+    )
+
+    // Must not contain globs in root, e.g. Windows UNC path \\foo\b*r
+    assert(
+      !pathHelper.hasRoot(pattern) || literalSegments[0],
+      `Invalid pattern '${pattern}'. Root segment must not contain globs.`
+    )
+
+    // Normalize slashes
+    pattern = pathHelper.normalizeSeparators(pattern)
+
+    // Replace leading `.` segment
+    if (pattern === '.' || pattern.startsWith(`.${path.sep}`)) {
+      pattern = Pattern.globEscape(process.cwd()) + pattern.substr(1)
+    }
+    // Replace leading `~` segment
+    else if (pattern === '~' || pattern.startsWith(`~${path.sep}`)) {
+      const homedir = os.homedir()
+      assert(homedir, 'Unable to determine HOME directory')
+      assert(
+        pathHelper.hasAbsoluteRoot(homedir),
+        `Expected HOME directory to be a rooted path. Actual '${homedir}'`
+      )
+      pattern = Pattern.globEscape(homedir) + pattern.substr(1)
+    }
+    // Replace relative drive root, e.g. pattern is C: or C:foo
+    else if (
+      IS_WINDOWS &&
+      (pattern.match(/^[A-Z]:$/i) || pattern.match(/^[A-Z]:[^\\]/i))
+    ) {
+      let root = pathHelper.ensureAbsoluteRoot(
+        'C:\\dummy-root',
+        pattern.substr(0, 2)
+      )
+      if (pattern.length > 2 && !root.endsWith('\\')) {
+        root += '\\'
+      }
+      pattern = Pattern.globEscape(root) + pattern.substr(2)
+    }
+    // Replace relative root, e.g. pattern is \ or \foo
+    else if (IS_WINDOWS && (pattern === '\\' || pattern.match(/^\\[^\\]/))) {
+      let root = pathHelper.ensureAbsoluteRoot('C:\\dummy-root', '\\')
+      if (!root.endsWith('\\')) {
+        root += '\\'
+      }
+      pattern = Pattern.globEscape(root) + pattern.substr(1)
+    }
+    // Otherwise ensure absolute root
+    else {
+      pattern = pathHelper.ensureAbsoluteRoot(
+        Pattern.globEscape(process.cwd()),
+        pattern
+      )
+    }
+
+    return pathHelper.normalizeSeparators(pattern)
+  }
+
+  /**
+   * Attempts to unescape a pattern segment to create a literal path segment.
+   * Otherwise returns empty string.
+   */
+  private static getLiteral(segment: string): string {
+    let literal = ''
+    for (let i = 0; i < segment.length; i++) {
+      const c = segment[i]
+      // Escape
+      if (c === '\\' && !IS_WINDOWS && i + 1 < segment.length) {
+        literal += segment[++i]
+        continue
+      }
+      // Wildcard
+      else if (c === '*' || c === '?') {
+        return ''
+      }
+      // Character set
+      else if (c === '[' && i + 1 < segment.length) {
+        let set = ''
+        let closed = -1
+        for (let i2 = i + 1; i2 < segment.length; i2++) {
+          const c2 = segment[i2]
+          // Escape
+          if (c2 === '\\' && !IS_WINDOWS && i2 + 1 < segment.length) {
+            set += segment[++i2]
+            continue
+          }
+          // Closed
+          else if (c2 === ']') {
+            closed = i2
+            break
+          }
+          // Otherwise
+          else {
+            set += c2
+          }
+        }
+
+        // Closed?
+        if (closed >= 0) {
+          // Cannot convert
+          if (set.length > 1) {
+            return ''
+          }
+
+          // Convert to literal
+          if (set) {
+            literal += set
+            i = closed
+            continue
+          }
+        }
+
+        // Otherwise fall thru
+      }
+
+      // Append
+      literal += c
+    }
+
+    return literal
+  }
+
+  /**
+   * Escapes regexp special characters
+   * https://javascript.info/regexp-escaping
+   */
+  private static regExpEscape(s: string): string {
+    return s.replace(/[[\\^$.|?*+()]/g, '\\$&')
+  }
+}

packages/glob/src/internal-search-state.ts

@@ -0,0 +1,9 @@
+export class SearchState {
+  readonly path: string
+  readonly level: number
+
+  constructor(path: string, level: number) {
+    this.path = path
+    this.level = level
+  }
+}