feat(complete): Dynamic powershell completions

clap_complete/src/dynamic/shells/mod.rs

@@ -3,10 +3,12 @@
 mod bash;
 mod fish;
 mod shell;
+mod powershell;
 
 pub use bash::*;
 pub use fish::*;
 pub use shell::*;
+pub use powershell::*;
 
 use std::ffi::OsString;
 use std::io::Write as _;

clap_complete/src/dynamic/shells/powershell.rs

@@ -0,0 +1,68 @@
+/// Completion support for Powershell
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct Powershell;
+
+impl crate::dynamic::Completer for Powershell {
+    fn file_name(&self, name: &str) -> String {
+        format!("{name}.ps1")
+    }
+
+    fn write_registration(
+        &self,
+        name: &str,
+        bin: &str,
+        completer: &str,
+        buf: &mut dyn std::io::Write,
+    ) -> Result<(), std::io::Error> {
+        let bin = shlex::quote(bin);
+        let completer = shlex::quote(completer);
+
+        writeln!(
+            buf,
+            r#"
+Register-ArgumentCompleter -Native -CommandName {bin} -ScriptBlock {{
+    param($wordToComplete, $commandAst, $cursorPosition)
+
+    $results = Invoke-Expression "&{bin} complete --shell powershell -- $($commandAst.ToString())";
+    $results | ForEach-Object {{
+        $split = $_.Split("`t");
+        $cmd = $split[0];
+
+        if ($split.Length -eq 2) {{
+            $help = $split[1];
+        }}
+        else {{
+            $help = $split[0];
+        }}
+        
+        [System.Management.Automation.CompletionResult]::new($cmd, $cmd, 'ParameterValue', $help)
+    }}
+}};
+        "#
+        )
+    }
+
+    fn write_complete(
+        &self,
+        cmd: &mut clap::Command,
+        args: Vec<std::ffi::OsString>,
+        current_dir: Option<&std::path::Path>,
+        buf: &mut dyn std::io::Write,
+    ) -> Result<(), std::io::Error> {
+        let index = args.len() - 1;
+        let completions = crate::dynamic::complete(cmd, args, index, current_dir)?;
+
+        for (completion, help) in completions {
+            write!(buf, "{}", completion.to_string_lossy())?;
+            if let Some(help) = help {
+                write!(
+                    buf,
+                    "\t{}",
+                    help.to_string().lines().next().unwrap_or_default()
+                )?;
+            }
+            writeln!(buf)?;
+        }
+        Ok(())
+    }
+}

clap_complete/src/dynamic/shells/shell.rs

@@ -12,6 +12,8 @@ pub enum Shell {
     Bash,
     /// Friendly Interactive SHell (fish)
     Fish,
+    /// Powershell
+    Powershell,
 }
 
 impl Display for Shell {
@@ -39,13 +41,14 @@ impl FromStr for Shell {
 // Hand-rolled so it can work even when `derive` feature is disabled
 impl ValueEnum for Shell {
     fn value_variants<'a>() -> &'a [Self] {
-        &[Shell::Bash, Shell::Fish]
+        &[Shell::Bash, Shell::Fish, Shell::Powershell]
     }
 
     fn to_possible_value<'a>(&self) -> Option<PossibleValue> {
         Some(match self {
             Shell::Bash => PossibleValue::new("bash"),
             Shell::Fish => PossibleValue::new("fish"),
+            Shell::Powershell => PossibleValue::new("powershell"),
         })
     }
 }
@@ -55,6 +58,7 @@ impl Shell {
         match self {
             Self::Bash => &super::Bash,
             Self::Fish => &super::Fish,
+            Self::Powershell => &super::Powershell,
         }
     }
 }