add auto-generated zsh completion

crates/pacdef_core/Cargo.toml

@@ -27,3 +27,4 @@ serde_derive = "1.0"
 serde = "1.0"
 
 pacdef_macros = { path = "../pacdef_macros", version = "0.1" }
+clap_complete = "4.1.3"

crates/pacdef_core/src/action.rs

@@ -5,6 +5,7 @@ use pacdef_macros::Action;
 #[derive(Debug, Action)]
 pub enum Actions {
     Clean,
+    Completion,
     Edit,
     Import,
     List,

crates/pacdef_core/src/args.rs

@@ -9,17 +9,18 @@ use crate::core::get_version_string;
 
 /// Build the `pacdef` argument parser, with subcommands for `version`,
 /// `group` and `package`.
-fn get_arg_parser() -> Command {
+pub fn build_cli() -> Command {
     let package_cmd = get_package_cmd();
     let group_cmd = get_group_cmd();
     let version_cmd = Command::new(VERSION).about("show version info");
+    let completion_cmd = Command::new(COMPLETION).about("generate shell completion");
 
     Command::new("pacdef")
         .about("declarative package manager for Linux")
         .version(get_version_string())
         .subcommand_required(true)
         .arg_required_else_help(true)
-        .subcommands([package_cmd, group_cmd, version_cmd])
+        .subcommands([package_cmd, group_cmd, version_cmd, completion_cmd])
 }
 
 /// Build the `pacdef group` subcommand.
@@ -67,7 +68,7 @@ fn get_group_cmd() -> Command {
 
     Command::new("group")
         .arg_required_else_help(true)
-        .about("TODO????")
+        .about("manage groups")
         .visible_alias("g")
         .subcommand_required(true)
         .subcommands([edit, import, list, new, remove, show])
@@ -95,7 +96,7 @@ fn get_package_cmd() -> Command {
 
     Command::new("package")
         .arg_required_else_help(true)
-        .about("TODO????")
+        .about("manage packages")
         .visible_alias("p")
         .subcommand_required(true)
         .subcommands([clean, review, unmanaged, search, sync])
@@ -104,7 +105,7 @@ fn get_package_cmd() -> Command {
 /// Get and parse the CLI arguments.
 #[must_use]
 pub fn get() -> clap::ArgMatches {
-    get_arg_parser().get_matches()
+    build_cli().get_matches()
 }
 
 /// For each file argument, return the absolute path to the file.

crates/pacdef_core/src/core.rs

@@ -5,6 +5,7 @@ use std::path::Path;
 
 use anyhow::{anyhow, bail, ensure, Context, Result};
 use clap::ArgMatches;
+use clap_complete::{generate, shells::Zsh};
 use const_format::formatcp;
 
 use crate::action::*;
@@ -84,6 +85,7 @@ impl Pacdef {
             },
 
             Some((VERSION, _)) => Ok(self.show_version()),
+            Some((COMPLETION, _)) => Ok(self.generate_shell_completion()),
 
             Some((_, _)) => panic!("{ACTION_NOT_MATCHED}"),
             None => unreachable!("{UNREACHABLE_ARM}"),
@@ -299,6 +301,16 @@ impl Pacdef {
 
         Ok(())
     }
+
+    #[allow(clippy::unused_self)]
+    fn generate_shell_completion(&self) {
+        generate(
+            Zsh,
+            &mut crate::args::build_cli(),
+            "pacdef",
+            &mut std::io::stdout(),
+        );
+    }
 }
 
 /// For the provided CLI arguments, get the path to each corresponding group file.