feat: shell completions (#343)

cargo-shuttle/Cargo.toml

@@ -15,6 +15,7 @@ cargo-edit = { version = "0.10.4", features = ["cli"] }
 cargo_metadata = "0.15.0"
 chrono = "0.4.22"
 clap = { version = "3.2.17", features = ["derive", "env"] }
+clap_complete = "3.2.5"
 crossbeam-channel = "0.5.6"
 crossterm = "0.25.0"
 dirs = "4.0.0"

cargo-shuttle/src/args.rs

@@ -6,6 +6,7 @@ use std::{
 };
 
 use clap::Parser;
+use clap_complete::Shell;
 use shuttle_common::project::ProjectName;
 use uuid::Uuid;
 
@@ -56,6 +57,15 @@ pub enum Command {
     Deployment(DeploymentCommand),
     /// create a new shuttle service
     Init(InitArgs),
+    /// generate shell completions
+    Generate {
+        /// which shell
+        #[clap(short, long, env, default_value_t = Shell::Bash)]
+        shell: Shell,
+        /// output to file or stdout by default
+        #[clap(short, long, env)]
+        output: Option<PathBuf>,
+    },
     /// view the status of a shuttle service
     Status,
     /// view the logs of a deployment in this shuttle service

cargo-shuttle/src/lib.rs

@@ -19,6 +19,8 @@ use cargo::core::resolver::CliFeatures;
 use cargo::core::Workspace;
 use cargo::ops::{PackageOpts, Packages};
 use cargo_metadata::Message;
+use clap::CommandFactory;
+use clap_complete::{generate, Shell};
 use config::RequestContext;
 use crossterm::style::Stylize;
 use factory::LocalFactory;
@@ -61,6 +63,7 @@ impl Shuttle {
 
         match args.cmd {
             Command::Init(init_args) => self.init(init_args).await,
+            Command::Generate { shell, output } => self.complete(shell, output).await,
             Command::Login(login_args) => self.login(login_args).await,
             Command::Run(run_args) => self.local_run(run_args).await,
             need_client => {
@@ -175,6 +178,17 @@ impl Shuttle {
         Ok(())
     }
 
+    async fn complete(&self, shell: Shell, output: Option<PathBuf>) -> Result<()> {
+        let name = env!("CARGO_PKG_NAME");
+        let mut app = Command::command();
+        match output {
+            Some(v) => generate(shell, &mut app, name, &mut File::create(v)?),
+            None => generate(shell, &mut app, name, &mut stdout()),
+        };
+
+        Ok(())
+    }
+
     async fn status(&self, client: &Client) -> Result<()> {
         let summary = client.get_service_summary(self.ctx.project_name()).await?;