Add bash completions

Signed-off-by: itowlson <ivan.towlson@fermyon.com>

Author: itowlson

Cargo.lock

@@ -18,6 +18,7 @@ bindle = { workspace = true }
 bytes = "1.1"
 chrono = "0.4"
 clap = { version = "3.1.15", features = ["derive", "env"] }
+clap_complete = "3.1.4"
 cloud = { path = "crates/cloud" }
 cloud-openapi = { git = "https://github.com/fermyon/cloud-openapi" }
 comfy-table = "5.0"

Cargo.toml

@@ -57,6 +57,8 @@ enum SpinApp {
     Plugin(PluginCommands),
     #[clap(subcommand, hide = true)]
     Trigger(TriggerCommands),
+    #[clap(hide = true, name = "generate-bash-completions")]
+    GenerateBashCompletions,
     #[clap(external_subcommand)]
     External(Vec<String>),
 }
@@ -82,6 +84,10 @@ impl SpinApp {
             Self::Trigger(TriggerCommands::Redis(cmd)) => cmd.run().await,
             Self::Login(cmd) => cmd.run().await,
             Self::Plugin(cmd) => cmd.run().await,
+            Self::GenerateBashCompletions => {
+                let mut cmd: clap::Command = SpinApp::into_app();
+                Ok(print_completions(clap_complete::Shell::Bash, &mut cmd))
+            },
             Self::External(cmd) => execute_external_subcommand(cmd, SpinApp::command()).await,
         }
     }
@@ -96,3 +102,7 @@ fn build_info() -> String {
         env!("VERGEN_GIT_COMMIT_DATE")
     )
 }
+
+fn print_completions<G: clap_complete::Generator>(gen: G, cmd: &mut clap::Command) {
+    clap_complete::generate(gen, cmd, cmd.get_name().to_string(), &mut std::io::stdout())
+}