feat(segkit): add setup subcommand to auto-install devbox

Adds `segkit setup` which checks if devbox is installed and automatically
runs Jetify's install script (https://get.jetify.com/devbox) if not found.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abueide

segkit/src/main.rs

@@ -3,6 +3,7 @@ use std::process::ExitCode;
 use clap::{Parser, Subcommand};
 
 mod delegate;
+mod setup;
 
 #[derive(Parser)]
 #[command(name = "segkit", version, about = "Segment SDK developer toolkit")]
@@ -28,6 +29,8 @@ enum Commands {
         #[arg(trailing_var_arg = true, allow_hyphen_values = true)]
         args: Vec<String>,
     },
+    /// Check and install required dependencies (devbox)
+    Setup,
 }
 
 fn main() -> ExitCode {
@@ -37,6 +40,7 @@ fn main() -> ExitCode {
         Some(Commands::Android { args }) => delegate::run("android.sh", &args),
         Some(Commands::Ios { args }) => delegate::run("ios.sh", &args),
         Some(Commands::Rn { args }) => delegate::run("rn.sh", &args),
+        Some(Commands::Setup) => setup::run(),
         None => {
             println!("segkit {}", env!("CARGO_PKG_VERSION"));
             ExitCode::SUCCESS

segkit/src/setup.rs

@@ -0,0 +1,55 @@
+use std::process::{Command, ExitCode};
+
+const DEVBOX_INSTALL_URL: &str = "https://get.jetify.com/devbox";
+
+fn is_installed(cmd: &str) -> bool {
+    which::which(cmd).is_ok()
+}
+
+fn install_devbox() -> Result<(), String> {
+    eprintln!("segkit: devbox not found, installing via {DEVBOX_INSTALL_URL}");
+
+    let curl_available = is_installed("curl");
+    let wget_available = is_installed("wget");
+
+    let status = if curl_available {
+        Command::new("sh")
+            .args(["-c", &format!("curl -fsSL {DEVBOX_INSTALL_URL} | bash")])
+            .status()
+    } else if wget_available {
+        Command::new("sh")
+            .args(["-c", &format!("wget -qO- {DEVBOX_INSTALL_URL} | bash")])
+            .status()
+    } else {
+        return Err("neither curl nor wget found — cannot download devbox installer".into());
+    };
+
+    match status {
+        Ok(s) if s.success() => Ok(()),
+        Ok(s) => Err(format!(
+            "devbox installer exited with code {}",
+            s.code().unwrap_or(-1)
+        )),
+        Err(e) => Err(format!("failed to run installer: {e}")),
+    }
+}
+
+pub fn run() -> ExitCode {
+    if is_installed("devbox") {
+        println!("devbox: installed");
+    } else {
+        if let Err(e) = install_devbox() {
+            eprintln!("segkit: {e}");
+            return ExitCode::FAILURE;
+        }
+        if !is_installed("devbox") {
+            eprintln!(
+                "segkit: devbox installed but not found on PATH — you may need to restart your shell"
+            );
+            return ExitCode::FAILURE;
+        }
+        println!("devbox: installed");
+    }
+
+    ExitCode::SUCCESS
+}

segkit/tests/cli.rs

@@ -22,7 +22,8 @@ fn help_flag() {
         .stdout(predicate::str::contains("Segment SDK developer toolkit"))
         .stdout(predicate::str::contains("android"))
         .stdout(predicate::str::contains("ios"))
-        .stdout(predicate::str::contains("rn"));
+        .stdout(predicate::str::contains("rn"))
+        .stdout(predicate::str::contains("setup"));
 }
 
 #[test]
@@ -66,3 +67,11 @@ fn rn_subcommand_without_script_fails_gracefully() {
         .failure()
         .stderr(predicate::str::contains("rn.sh not found"));
 }
+
+#[test]
+fn setup_detects_devbox() {
+    segkit()
+        .arg("setup")
+        .assert()
+        .stdout(predicate::str::contains("devbox:"));
+}