fix(stdlib): address review feedback on Os bindings

- Change os.path.getsize return type from int to int64 to handle files >= 2 GiB
- Reorder getpid/getppid next to getenv; move walk near rmdir for grouping
- Improve walk test to assert dirpath="." and that subdirs+files match listdir
- Add getppid test
- Add walk(topdown=false) test using a controlled temp dir
- Use unique /tmp paths and clean up after makedirs/walk tests
- Revert CHANGELOG.md addition (AGENTS.md forbids modifying CHANGELOG)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dbrattli

CHANGELOG.md

@@ -46,10 +46,6 @@ All notable changes to this project will be documented in this file.
 
 ## Unreleased
 
-### 🚀 Features
-
-* *(stdlib)* Add `os.makedirs(path, exist_ok)` overload, `os.walk`, `os.getpid`, `os.getppid`, `os.path.isabs`, `os.path.islink`, `os.path.realpath`, `os.path.getsize` to Os module
-
 ### 🐞 Bug Fixes
 
 * Fix `math.factorial` binding: changed signature from `float -> float` to `int -> int` to match Python 3.12+ where float arguments raise `TypeError`. Fixes test to use integer literals.

src/stdlib/Os.fs

@@ -30,6 +30,12 @@ type IExports =
     /// Return the value of the environment variable key or default if not set
     /// See https://docs.python.org/3/library/os.html#os.getenv
     abstract getenv: key: string * ``default``: string -> string
+    /// Return the current process id.
+    /// See https://docs.python.org/3/library/os.html#os.getpid
+    abstract getpid: unit -> int
+    /// Return the parent process id.
+    /// See https://docs.python.org/3/library/os.html#os.getppid
+    abstract getppid: unit -> int
     /// Send signal sig to the process pid
     /// See https://docs.python.org/3/library/os.html#os.kill
     abstract kill: pid: int * ``sig``: int -> unit
@@ -51,21 +57,6 @@ type IExports =
     /// See https://docs.python.org/3/library/os.html#os.makedirs
     [<Emit("$0.makedirs($1, $2, $3)")>]
     abstract makedirs: path: string * mode: int * exist_ok: bool -> unit
-    /// Return the current process id.
-    /// See https://docs.python.org/3/library/os.html#os.getpid
-    abstract getpid: unit -> int
-    /// Return the parent process id.
-    /// See https://docs.python.org/3/library/os.html#os.getppid
-    abstract getppid: unit -> int
-    /// Walk a directory tree, yielding (dirpath, dirnames, filenames) for each directory.
-    /// When topdown is true (the default) the caller can modify the dirnames list in-place
-    /// to prune the search or impose a specific visiting order.
-    /// See https://docs.python.org/3/library/os.html#os.walk
-    abstract walk: top: string -> seq<string * ResizeArray<string> * ResizeArray<string>>
-    /// Walk a directory tree top-down or bottom-up (topdown=false).
-    /// See https://docs.python.org/3/library/os.html#os.walk
-    [<Emit("$0.walk($1, topdown=$2)")>]
-    abstract walk: top: string * topdown: bool -> seq<string * ResizeArray<string> * ResizeArray<string>>
     /// Set the environment variable named key to the string value
     /// See https://docs.python.org/3/library/os.html#os.putenv
     abstract putenv: key: string * value: string -> unit
@@ -81,6 +72,15 @@ type IExports =
     /// Remove (delete) the directory path
     /// See https://docs.python.org/3/library/os.html#os.rmdir
     abstract rmdir: path: string -> unit
+    /// Walk a directory tree, yielding (dirpath, dirnames, filenames) for each directory.
+    /// When topdown is true (the default) the caller can modify the dirnames list in-place
+    /// to prune the search or impose a specific visiting order.
+    /// See https://docs.python.org/3/library/os.html#os.walk
+    abstract walk: top: string -> seq<string * ResizeArray<string> * ResizeArray<string>>
+    /// Walk a directory tree top-down or bottom-up (topdown=false).
+    /// See https://docs.python.org/3/library/os.html#os.walk
+    [<Emit("$0.walk($1, topdown=$2)")>]
+    abstract walk: top: string * topdown: bool -> seq<string * ResizeArray<string> * ResizeArray<string>>
     /// Test whether a path exists
     /// See https://docs.python.org/3/library/os.path.html#os.path.exists
     abstract path: PathModule
@@ -128,7 +128,7 @@ and [<Erase>] PathModule =
     abstract realpath: path: string -> string
     /// Return the size, in bytes, of path
     /// See https://docs.python.org/3/library/os.path.html#os.path.getsize
-    abstract getsize: path: string -> int
+    abstract getsize: path: string -> int64
 
 
 /// Miscellaneous operating system interfaces

test/TestOs.fs

@@ -80,26 +80,50 @@ let ``test os.path.islink works`` () =
 [<Fact>]
 let ``test os.path.getsize works`` () =
     // The test directory itself has a positive size
-    os.path.getsize "." > 0 |> equal true
+    os.path.getsize "." > 0L |> equal true
 
 [<Fact>]
 let ``test os.getpid works`` () =
     let pid = os.getpid ()
     pid > 0 |> equal true
 
+[<Fact>]
+let ``test os.getppid works`` () =
+    let ppid = os.getppid ()
+    ppid > 0 |> equal true
+
 [<Fact>]
 let ``test os.makedirs with exist_ok works`` () =
-    let dir = "/tmp/fable_test_makedirs"
+    let dir = sprintf "/tmp/fable_test_makedirs_%d" (os.getpid ())
     os.makedirs (dir, true)
     os.path.isdir dir |> equal true
     // Second call must not raise when exist_ok=true
     os.makedirs (dir, true)
     os.path.isdir dir |> equal true
+    os.rmdir dir
 
 [<Fact>]
 let ``test os.walk yields entries`` () =
     let entries = os.walk "." |> Seq.truncate 1 |> Seq.toList
-    // At minimum one entry (the root ".")
-    entries.Length > 0 |> equal true
-    let _dirpath, _subdirs, _files = entries.[0]
-    true |> equal true
+    entries.Length |> equal 1
+    let dirpath, subdirs, files = entries.[0]
+    dirpath |> equal "."
+    // The first walk entry's dirnames + filenames should equal listdir of the root
+    let walkAll = Seq.append subdirs files |> Seq.sort |> Seq.toList
+    let listdirAll = os.listdir "." |> Array.sort |> Array.toList
+    walkAll |> equal listdirAll
+
+[<Fact>]
+let ``test os.walk with topdown=false works`` () =
+    let root = sprintf "/tmp/fable_test_walk_%d" (os.getpid ())
+    let nested = os.path.join (root, "nested")
+    os.makedirs (nested, true)
+    let entries = os.walk (root, false) |> Seq.toList
+    // Bottom-up: deepest dir is yielded first, root is yielded last
+    entries.Length |> equal 2
+    let firstDir, _, _ = entries.[0]
+    let lastDir, _, _ = List.last entries
+    firstDir |> equal nested
+    lastDir |> equal root
+    os.rmdir nested
+    os.rmdir root