Add sway, swaymsg and swaynag completions for pwsh

completions/pwsh/sway.ps1

@@ -0,0 +1,26 @@
+# Based on the following documentation and tons of trial and error:
+# https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/register-argumentcompleter?view=powershell-7.1
+
+Register-ArgumentCompleter -Native -CommandName sway -ScriptBlock {
+  param($wordToComplete, $commandAst, $cursorPosition)
+
+  $completions = @(
+    '--help',
+    '--config',
+    '--validate',
+    '--debug',
+    '--version',
+    '--verbose',
+    '--get-socketpath'
+  )
+
+  if ($commandAst.CommandElements.Count -ge 2) {
+    if ($commandAst.CommandElements[1].ToString() -in @( '-c', '--config' )) {
+      $completions = Get-ChildItem | Select-Object -ExpandProperty Name
+    }
+  }
+
+  $completions | Where-Object { $_.StartsWith($wordToComplete) } | ForEach-Object {
+    [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_)
+  }
+}