feat: Add nushell completions

src/commands/completions.rs

@@ -1,15 +1,18 @@
 use clap::{Args, CommandFactory};
-use clap_complete::{generate, Shell as CompletionShell};
+use clap_complete::generate;
 use miette::Result;
+use shells::Shells;
 
 use crate::commands::BlueBuildArgs;
 
 use super::BlueBuildCommand;
 
+mod shells;
+
 #[derive(Debug, Clone, Args)]
 pub struct CompletionsCommand {
     #[arg(value_enum)]
-    shell: CompletionShell,
+    shell: Shells,
 }
 
 impl BlueBuildCommand for CompletionsCommand {

src/commands/completions/shells.rs

@@ -0,0 +1,52 @@
+use clap::ValueEnum;
+use clap_complete::{Generator, Shell as CompletionShell};
+use clap_complete_nushell::Nushell;
+
+#[derive(Debug, Clone, Copy, ValueEnum, PartialEq, Eq, Hash)]
+pub enum Shells {
+    /// Bourne Again `SHell` (bash)
+    Bash,
+    /// Elvish shell
+    Elvish,
+    /// Friendly Interactive `SHell` (fish)
+    Fish,
+    /// `PowerShell`
+    PowerShell,
+    /// Z `SHell` (zsh)
+    Zsh,
+    /// Nushell (nu)
+    Nushell,
+}
+
+impl Generator for Shells {
+    fn file_name(&self, name: &str) -> String {
+        match *self {
+            Self::Bash => CompletionShell::Bash.file_name(name),
+            Self::Elvish => CompletionShell::Elvish.file_name(name),
+            Self::Fish => CompletionShell::Fish.file_name(name),
+            Self::PowerShell => CompletionShell::PowerShell.file_name(name),
+            Self::Zsh => CompletionShell::Zsh.file_name(name),
+            Self::Nushell => Nushell.file_name(name),
+        }
+    }
+
+    fn generate(&self, cmd: &clap::Command, buf: &mut dyn std::io::Write) {
+        match *self {
+            Self::Bash => CompletionShell::Bash.generate(cmd, buf),
+            Self::Elvish => CompletionShell::Elvish.generate(cmd, buf),
+            Self::Fish => CompletionShell::Fish.generate(cmd, buf),
+            Self::PowerShell => CompletionShell::PowerShell.generate(cmd, buf),
+            Self::Zsh => CompletionShell::Zsh.generate(cmd, buf),
+            Self::Nushell => Nushell.generate(cmd, buf),
+        }
+    }
+}
+
+impl std::fmt::Display for Shells {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.to_possible_value()
+            .expect("no values are skipped")
+            .get_name()
+            .fmt(f)
+    }
+}