add isCWD, correct relative() when cwd is root

Fix: isaacs/node-glob#584

README.md

@@ -516,6 +516,11 @@ pathname matches, due to unicode normalization mismatches.
 Always use this method instead of testing the `path.name`
 property directly.
 
+#### `path.isCWD`
+
+Set to true if this `Path` object is the current working
+directory of the `PathScurry` collection that contains it.
+
 #### `path.getType()`
 
 Returns the type of the Path object, `'File'`, `'Directory'`,

package.json

@@ -61,6 +61,9 @@
     "typedoc": "^0.25.12",
     "typescript": "^5.4.3"
   },
+  "tap": {
+    "typecheck": true
+  },
   "engines": {
     "node": ">=16 || 14 >=14.17"
   },

src/index.ts

@@ -299,6 +299,12 @@ export abstract class PathBase implements Dirent {
    */
   nocase: boolean
 
+  /**
+   * boolean indicating that this path is the current working directory
+   * of the PathScurry collection that contains it.
+   */
+  isCWD: boolean = false
+
   /**
    * the string or regexp used to split paths. On posix, it is `'/'`, and on
    * windows it is a RegExp matching either `'/'` or `'\\'`
@@ -581,6 +587,7 @@ export abstract class PathBase implements Dirent {
    * the cwd, then this ends up being equivalent to the fullpath()
    */
   relative(): string {
+    if (this.isCWD) return ''
     if (this.#relative !== undefined) {
       return this.#relative
     }
@@ -601,6 +608,7 @@ export abstract class PathBase implements Dirent {
    */
   relativePosix(): string {
     if (this.sep === '/') return this.relative()
+    if (this.isCWD) return ''
     if (this.#relativePosix !== undefined) return this.#relativePosix
     const name = this.name
     const p = this.parent
@@ -1348,6 +1356,8 @@ export abstract class PathBase implements Dirent {
    */
   [setAsCwd](oldCwd: PathBase): void {
     if (oldCwd === this) return
+    oldCwd.isCWD = false
+    this.isCWD = true
 
     const changed = new Set<PathBase>([])
     let rp = []

test/index.ts

@@ -137,6 +137,10 @@ t.test('platform-specific', t => {
     t.equal(pw.resolve('//prp1/'), 'C:\\prp1')
     t.equal(pw.resolvePosix('//prp1/'), '//?/C:/prp1')
     t.equal(pw.cwd.resolve('../../../../../../../'), pw.root)
+    pw.chdir(pw.root)
+    t.equal(pw.relativePosix('C:/some'), 'some')
+    t.equal(pw.relative('C:/some/PATH'), 'some\\path')
+    t.equal(pw.relativePosix('C:/some/PATH'), 'some/path')
     t.equal(new PathScurry('/prp2').cwd.fullpath(), 'C:\\prp2')
     t.equal(new PathScurry('\\prp3').resolve(), 'C:\\prp3')
     t.equal(new PathScurry('\\prp3').resolvePosix(), '//?/C:/prp3')
@@ -179,6 +183,10 @@ t.test('platform-specific', t => {
       '/x/y/some/absolute/path',
     )
     t.equal(pw.cwd.resolve('foo'), pw.cwd.resolve('x/../FOO'))
+    pw.chdir(pw.root)
+    t.equal(pw.relativePosix('/some'), 'some')
+    t.equal(pw.relative('/some/PATH'), 'some/path')
+    t.equal(pw.relativePosix('/some/PATH'), 'some/path')
     t.end()
   })
 
@@ -206,6 +214,10 @@ t.test('platform-specific', t => {
     t.equal(pw.cwd.resolve('../../../../../../../'), pw.root)
     t.equal(pw.cwd.resolve('foo'), pw.cwd.resolve('x/../foo'))
     t.not(pw.cwd.resolve('foo'), pw.cwd.resolve('x/../FOO'))
+    pw.chdir(pw.root)
+    t.equal(pw.relativePosix('/some'), 'some')
+    t.equal(pw.relative('/some/PATH'), 'some/PATH')
+    t.equal(pw.relativePosix('/some/PATH'), 'some/PATH')
     t.end()
   })