feat(completions): Offer Nushell completions (#6366)

---------

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

Cargo.lock

@@ -437,6 +437,16 @@ dependencies = [
  "clap",
 ]
 
+[[package]]
+name = "clap_complete_nushell"
+version = "4.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "315902e790cc6e5ddd20cbd313c1d0d49db77f191e149f96397230fb82a17677"
+dependencies = [
+ "clap",
+ "clap_complete",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.5.28"
@@ -3093,6 +3103,7 @@ dependencies = [
  "chrono",
  "clap",
  "clap_complete",
+ "clap_complete_nushell",
  "deelevate",
  "dirs 6.0.0",
  "dunce",

Cargo.toml

@@ -45,6 +45,7 @@ gix-faster = ["gix-features/zlib-stock", "gix/fast-sha1"]
 chrono = { version = "0.4.40", default-features = false, features = ["clock", "std", "wasmbind"] }
 clap = { version = "4.5.31", features = ["derive", "cargo", "unicode"] }
 clap_complete = "4.5.46"
+clap_complete_nushell = "4.5.4"
 dirs = "6.0.0"
 dunce = "1.0.5"
 # default feature restriction addresses https://github.com/starship/starship/issues/4251

src/main.rs

@@ -6,8 +6,8 @@ use std::path::PathBuf;
 use std::thread::available_parallelism;
 use std::time::SystemTime;
 
-use clap::{CommandFactory, Parser, Subcommand};
+use clap::{CommandFactory, Parser, Subcommand, ValueEnum};
-use clap_complete::{generate, Shell as CompletionShell};
+use clap_complete::generate;
 use rand::distributions::Alphanumeric;
 use rand::Rng;
 use starship::context::{Context, Properties, Target};
@@ -28,6 +28,36 @@ struct Cli {
     command: Commands,
 }
 
+#[derive(clap::Parser, ValueEnum, Debug, Clone, PartialEq, Eq)]
+enum CompletionShell {
+    Bash,
+    Elvish,
+    Fish,
+    Nushell,
+    PowerShell,
+    Zsh,
+}
+
+fn generate_shell(shell: impl clap_complete::Generator) {
+    generate(
+        shell,
+        &mut Cli::command(),
+        "starship",
+        &mut io::stdout().lock(),
+    )
+}
+
+fn generate_completions(shell: CompletionShell) {
+    match shell {
+        CompletionShell::Bash => generate_shell(clap_complete::Shell::Bash),
+        CompletionShell::Elvish => generate_shell(clap_complete::Shell::Elvish),
+        CompletionShell::Fish => generate_shell(clap_complete::Shell::Fish),
+        CompletionShell::PowerShell => generate_shell(clap_complete::Shell::PowerShell),
+        CompletionShell::Zsh => generate_shell(clap_complete::Shell::Zsh),
+        CompletionShell::Nushell => generate_shell(clap_complete_nushell::Nushell),
+    }
+}
+
 #[derive(Subcommand, Debug)]
 enum Commands {
     /// Create a pre-populated GitHub issue with information about your configuration
@@ -236,12 +266,7 @@ fn main() {
         }
         Commands::Explain(props) => print::explain(props),
         Commands::Timings(props) => print::timings(props),
-        Commands::Completions { shell } => generate(
+        Commands::Completions { shell } => generate_completions(shell),
-            shell,
-            &mut Cli::command(),
-            "starship",
-            &mut io::stdout().lock(),
-        ),
         Commands::Session => println!(
             "{}",
             rand::thread_rng()