devenv: add shell completions

package.nix

@@ -42,5 +42,16 @@ pkgs.rustPlatform.buildRustPackage {
     # Generate manpages
     cargo xtask generate-manpages --out-dir man
     installManPage man/*
+
+    # Generate shell completions
+    compdir=./completions
+    for shell in bash fish zsh; do
+      cargo xtask generate-shell-completion $shell --out-dir $compdir
+    done
+
+    installShellCompletion --cmd devenv \
+      --bash $compdir/devenv.bash \
+      --fish $compdir/devenv.fish \
+      --zsh $compdir/_devenv
   '';
 }

xtask/Cargo.toml

@@ -5,6 +5,7 @@ edition.workspace = true
 
 [dependencies]
 clap.workspace = true
+clap_complete = "4.5.7"
 clap_mangen = "0.2.22"
 devenv = { path = "../devenv" }
 miette.workspace = true

xtask/src/cli.rs

@@ -0,0 +1 @@
+include!("../../devenv/src/cli.rs");

xtask/src/lib.rs

@@ -0,0 +1,3 @@
+pub(crate) mod cli;
+pub mod manpage;
+pub mod shell_completion;

xtask/src/main.rs

@@ -1,7 +1,6 @@
 use clap::Parser;
 use miette::Result;
-
-mod manpage;
+use xtask::{manpage, shell_completion};
 
 #[derive(clap::Parser)]
 struct Cli {
@@ -20,12 +19,27 @@ enum Command {
         )]
         out_dir: std::path::PathBuf,
     },
+    GenerateShellCompletion {
+        #[clap(value_enum)]
+        shell: clap_complete::Shell,
+
+        #[clap(
+            long,
+            value_parser,
+            value_hint = clap::ValueHint::DirPath,
+            default_value_os_t = shell_completion::default_out_dir()
+        )]
+        out_dir: std::path::PathBuf,
+    },
 }
 
 fn main() -> Result<()> {
     let cli = Cli::parse();
 
     match cli.command {
-        Command::GenerateManpages { out_dir } => manpage::generate_manpages(out_dir),
+        Command::GenerateManpages { out_dir } => manpage::generate(out_dir),
+        Command::GenerateShellCompletion { shell, out_dir } => {
+            shell_completion::generate(shell, out_dir)
+        }
     }
 }

xtask/src/manpage.rs

@@ -1,16 +1,13 @@
+use super::cli::Cli;
 use clap::CommandFactory;
 use miette::{IntoDiagnostic, Result};
 use std::fs;
 use std::path::{Path, PathBuf};
 
-mod cli {
-    include!("../../devenv/src/cli.rs");
-}
-
-pub fn generate_manpages(out_dir: impl AsRef<Path>) -> Result<()> {
+pub fn generate(out_dir: impl AsRef<Path>) -> Result<()> {
     fs::create_dir_all(&out_dir).into_diagnostic()?;
-    clap_mangen::generate_to(cli::Cli::command(), &out_dir).into_diagnostic()?;
-    println!("Generated man pages to {}", out_dir.as_ref().display());
+    clap_mangen::generate_to(Cli::command(), &out_dir).into_diagnostic()?;
+    eprintln!("Generated man pages to {}", out_dir.as_ref().display());
     Ok(())
 }
 

xtask/src/shell_completion.rs

@@ -0,0 +1,23 @@
+use crate::cli::Cli;
+use clap::CommandFactory;
+use miette::{IntoDiagnostic, Result};
+use std::fs;
+use std::path::{Path, PathBuf};
+
+pub fn generate(shell: clap_complete::Shell, out_dir: impl AsRef<Path>) -> Result<()> {
+    fs::create_dir_all(&out_dir).into_diagnostic()?;
+    let mut cmd = Cli::command();
+    let bin_name = cmd.get_name().to_string();
+    let completion_path = clap_complete::generate_to(shell, &mut cmd, bin_name, out_dir.as_ref())
+        .into_diagnostic()?;
+    eprintln!(
+        "Generated {} completions to {}",
+        shell,
+        completion_path.display()
+    );
+    Ok(())
+}
+
+pub fn default_out_dir() -> PathBuf {
+    std::env::current_dir().unwrap()
+}