add generation of shell completion (#22)

linkup-cli/Cargo.toml

@@ -10,6 +10,7 @@ path = "src/main.rs"
 [dependencies]
 actix-web = "4.3.1"
 clap = { version = "4.1.8", features = ["derive"] }
+clap_complete = "4.4.0"
 colored = "2"
 ctrlc = { version = "3.0", features = ["termination"] }
 daemonize = "0.5.0"

linkup-cli/src/completion.rs

@@ -0,0 +1,17 @@
+use std::io::stdout;
+
+use clap::{Command, CommandFactory};
+use clap_complete::{generate, Generator, Shell};
+
+use crate::{Cli, CliError};
+
+pub fn completion(shell: &Option<Shell>) -> Result<(), CliError> {
+    if let Some(shell) = shell {
+        let mut cmd = Cli::command();
+        print_completions(shell, &mut cmd);
+    }
+    Ok(())
+}
+fn print_completions<G: Generator + Clone>(gen: &G, cmd: &mut Command) {
+    generate(gen.clone(), cmd, cmd.get_name().to_string(), &mut stdout());
+}

linkup-cli/src/main.rs

@@ -1,11 +1,13 @@
 use std::{env, fs, io::ErrorKind, path::PathBuf};
 
 use clap::{Parser, Subcommand};
+use clap_complete::Shell;
 use thiserror::Error;
 
 mod background_booting;
 mod background_local_server;
 mod background_tunnel;
+mod completion;
 mod local_config;
 mod local_server;
 mod remote_local;
@@ -15,6 +17,7 @@ mod start;
 mod status;
 mod stop;
 
+use completion::completion;
 use remote_local::{local, remote};
 use reset::reset;
 use start::start;
@@ -113,14 +116,24 @@ struct Cli {
 enum Commands {
     #[clap(about = "Start a new linkup session")]
     Start {
-        #[arg(short, long)]
+        #[arg(
+            short,
+            long,
+            value_name = "CONFIG",
+            help = "Path to config file, overriding environment variable."
+        )]
         config: Option<String>,
     },
     #[clap(about = "Stop a running linkup session")]
     Stop {},
     #[clap(about = "Reset a linkup session")]
     Reset {
-        #[arg(short, long)]
+        #[arg(
+            short,
+            long,
+            value_name = "CONFIG",
+            help = "Path to config file, overriding environment variable."
+        )]
         config: Option<String>,
     },
     #[clap(about = "Route session traffic to a local service")]
@@ -135,6 +148,11 @@ enum Commands {
         #[arg(short, long)]
         all: bool,
     },
+    #[clap(about = "Generate completions for your shell")]
+    Completion {
+        #[arg(long, value_enum)]
+        shell: Option<Shell>,
+    },
 }
 
 fn main() -> Result<(), CliError> {
@@ -149,5 +167,6 @@ fn main() -> Result<(), CliError> {
         Commands::Local { service_names } => local(service_names.clone()),
         Commands::Remote { service_names } => remote(service_names.clone()),
         Commands::Status { json, all } => status(*json, *all),
+        Commands::Completion { shell } => completion(shell),
     }
 }