add depth() method

Returns the depth of the current path in the directory tree.

Fix: #3
Re: isaacs/node-glob#296

README.md

@@ -318,6 +318,13 @@ single tick if the stream is fully consumed.
 Path object representing the current working directory for the
 PathScurry.
 
+#### `pw.depth(path?: Path | string): number`
+
+Return the depth of the specified path (or the PathScurry cwd)
+within the directory tree.
+
+Root entries have a depth of `0`.
+
 #### `pw.resolve(...paths: string[])`
 
 Caching `path.resolve()`.
@@ -459,6 +466,11 @@ pathname matches, due to unicode normalization mismatches.
 Always use this method instead of testing the `path.name`
 property directly.
 
+#### `path.depth()`
+
+Return the depth of the Path entry within the directory tree.
+Root paths have a depth of `0`.
+
 #### `path.fullpath()`
 
 The fully resolved path to the entry.

src/index.ts

@@ -204,6 +204,7 @@ export abstract class PathBase implements Dirent {
  abstract sep: string
 
  #matchName: string
+ #depth?: number
  #fullpath?: string
  #relative?: string
  #type: number
@@ -238,6 +239,17 @@ export abstract class PathBase implements Dirent {
  this.parent = opts.parent
  }
 
+ /**
+ * Returns the depth of the Path object from its root.
+ *
+ * For example, a path at `/foo/bar` would have a depth of 2.
+ */
+ depth(): number {
+ if (this.#depth !== undefined) return this.#depth
+ if (!this.parent) return (this.#depth = 0)
+ return (this.#depth = this.parent.depth() + 1)
+ }
+
  /**
  * @internal
  */
@@ -1293,6 +1305,16 @@ export abstract class PathScurryBase {
  this.cwd = prev
  }
 
+ /**
+ * Get the depth of a provided path, string, or the cwd
+ */
+ depth(path: Path | string = this.cwd): number {
+ if (typeof path === 'string') {
+ path = this.cwd.resolve(path)
+ }
+ return path.depth()
+ }
+
  /**
  * Parse the root portion of a path string
  *

test/index.ts

@@ -1406,3 +1406,13 @@ t.test('can use file url as cwd option', t => {
  t.equal(pus.cwd.fullpath(), process.cwd())
  t.end()
 })
+
+t.test('depth', t => {
+ const ps = new PathScurry('/a/b/c/d')
+ t.equal(ps.depth(), 4)
+ t.equal(ps.depth('e/../g'), 5)
+ t.equal(ps.root.depth(), 0)
+ t.equal(ps.cwd.depth(), 4)
+ t.equal(ps.cwd.parent?.depth(), 3)
+ t.end()
+})