add completion support

Cargo.toml

@@ -20,6 +20,7 @@ base64 = "0.21.7"
 clap = { version = "4.4.18", features = ["derive", "env", "wrap_help"] }
 clap-markdown = "0.1.3"
 clap-verbosity-flag = "2.1.2"
+clap_complete = "4.4.10"
 log = "0.4.20"
 ocli = "0.1.1"
 serde_yaml = "0.9.31"

src/cli.rs

@@ -7,6 +7,10 @@ use clap_verbosity_flag::{InfoLevel, Verbosity};
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None, arg_required_else_help = true)]
 pub struct Cli {
+    /// Generate the completion code for this shell
+    #[arg(long, name = "SHELL")]
+    pub completion: Option<clap_complete::Shell>,
+
     #[command(flatten)]
     pub verbose: Verbosity<InfoLevel>,
 

src/main.rs

@@ -1,6 +1,9 @@
 #[macro_use]
 extern crate log;
 
+use std::io;
+
+use clap::CommandFactory;
 use clap::Parser;
 
 use yage::cli;
@@ -18,6 +21,11 @@ fn run() -> error::Result<()> {
         ocli::init(level).unwrap();
     }
 
+    if let Some(shell) = cli.completion {
+        clap_complete::generate(shell, &mut cli::Cli::command(), "yage", &mut io::stdout());
+        return Ok(());
+    }
+
     if cli.markdown_help {
         clap_markdown::print_help_markdown::<cli::Cli>();
         return Ok(());