scripts: west_commands: Add powershell autocompletion (west -b)

Windows powershell can by default not autocomplete known boards when
tapping which can cause frustration when you can't quite remember the
exact name or you don't want to type it out.
west build .\path\to\application\ -p -b stm<tab> will search for
available board including 'stm' in their name.

Signed-off-by: Tais Hjortshøj <tbh@mjolner.dk>

doc/develop/west/install.rst

@@ -53,6 +53,7 @@ West currently supports shell completion in the following shells:
 * bash
 * zsh
 * fish
+* powershell (board qualifiers only)
 
 In order to enable shell completion, you will need to obtain the corresponding
 completion script and have it sourced.
@@ -102,5 +103,22 @@ Using the completion scripts:
 
       west completion fish > $HOME/.config/fish/completions/west.fish
 
+  .. group-tab:: powershell
+
+    *One-time setup*:
+
+    .. code-block:: powershell
+
+      west completion powershell | Out-String | Invoke-Expression
+
+    *Permanent setup*:
+
+    .. code-block:: powershell
+
+      Set-ExecutionPolicy RemoteSigned -Scope CurrentUser
+      New-item -type file -force $PROFILE
+      west completion powershell > $HOME/west-completion.ps1
+      (Add-Content -Path $PROFILE -Value ". '{$HOME/west-completion.ps1}'")
+
 .. _PyPI:
    https://pypi.org/project/west/

doc/develop/west/zephyr-cmds.rst

@@ -40,6 +40,7 @@ It currently supports the following shells:
 - bash
 - zsh
 - fish
+- powershell (board qualifiers only)
 
 Additional instructions are available in the command's help::
 

scripts/west_commands/completion.py

@@ -36,6 +36,14 @@ to stdout. Using the completion scripts:
     # permanent
     west completion fish > $HOME/.config/fish/completions/west.fish
 
+  powershell:
+    # one-time
+    west completion powershell | Out-String | Invoke-Expression
+    # permanent
+    Set-ExecutionPolicy RemoteSigned -Scope CurrentUser
+    New-item -type file -force $PROFILE
+    (Add-Content -Path $PROFILE -Value ". '{$HOME/west-completion.ps1}'")
+
 positional arguments:
   source_dir            application source directory
   cmake_opt             extra options to pass to cmake; implies -c
@@ -44,6 +52,12 @@ positional arguments:
 
 
 class Completion(WestCommand):
+    _EXT_MAPPING = {
+        "bash": "bash",
+        "fish": "fish",
+        "powershell": "ps1",
+        "zsh": "zsh",
+    }
 
     def __init__(self):
         super().__init__(
@@ -62,7 +76,7 @@ class Completion(WestCommand):
 
         # Remember to update west-completion.bash if you add or remove
         # flags
-        parser.add_argument('shell', nargs=1, choices=['bash', 'zsh', 'fish'],
+        parser.add_argument('shell', nargs=1, choices=self._EXT_MAPPING.keys(),
                             help='''Shell that which the completion
                             script is intended for.''')
         return parser
@@ -71,7 +85,7 @@ class Completion(WestCommand):
         cf = os.path.join(os.path.dirname(os.path.realpath(__file__)),
                           *COMPLETION_REL_PATH.split('/'))
 
-        cf += '.' + args.shell[0]
+        cf += '.' + self._EXT_MAPPING[args.shell[0]]
 
         try:
             with open(cf, 'r') as f:

scripts/west_commands/completion/west-completion.ps1

@@ -0,0 +1,47 @@
+# Copyright © 2025, Tais Hjortshøj <tbh@mjolner.dk> / Mjølner Informatics A/S
+# SPDX-License-Identifier: Apache-2.0
+
+# region custom west board finder initialize
+$s = {
+    param($wordToComplete, $commandAst, $cursorPosition)
+
+    function Get-MatchingBoards {
+        param($wordToComplete)
+        west boards | Out-String | ForEach-Object {
+             $_ -split '\r?\n' | Where-Object { $_ -CMatch "^$wordToComplete.*" } | Sort-Object
+        }
+    }
+
+    $commandDecider = (($commandAst -split ' ') | Select-Object -First 2 -ExpandProperty $_) -join ' '
+    if ($commandDecider -eq 'west build') {
+
+        $argDecider = (($commandAst -split ' ') | Select-Object -Last 2)
+
+        if ($argDecider -contains '-b' -or $argDecider -contains '--board') {
+            $boardsFound = Get-MatchingBoards -wordToComplete $wordToComplete
+            $output = $boardsFound
+        } else {
+            # Fallback to default behavior of suggesting files in the current directory
+            $output = (Get-NexusRepository).Name
+        }
+    } else {
+        # Fallback to default behavior of suggesting files in the current directory
+        $output = (Get-NexusRepository).Name
+    }
+
+    # Uncomment the following lines to log the output for debugging purposes
+    # @("wordToComplete:  $wordToComplete",
+    # "commandAst:        $commandAst",
+    # "cursorPosition:    $cursorPosition",
+    # "commandDecider:    $commandDecider",
+    # "argDecider:        $argDecider",
+    # "",
+    # "boardsFound:",
+    # ($boardsFound | ForEach-Object { $_ -split ' '})
+    # ) | Set-Content log.txt
+
+    $output
+}
+Register-ArgumentCompleter -Native -CommandName west -ScriptBlock $s
+echo "West completion tool loaded"
+# endregion