feat(cli): hint users for newer version (#166)

Author: goulvenclech

.sampo/changesets/bold-stormcaller-louhi.md

@@ -0,0 +1,5 @@
+---
+cargo/sampo: minor
+---
+
+Sampo now checks for updates once per day, and displays a hint when a newer version is available on crates.io. The check is non-blocking and fails silently if offline.

Cargo.lock

@@ -21,10 +21,11 @@ rustc-hash = "2.0"
 semver = "1.0.26"
 serde_json = "1.0"
 toml = "0.8"
-reqwest = { version = "0.12", features = ["json"] }
+reqwest = { version = "0.12", features = ["json", "blocking"] }
 sampo-core = { version = "0.10.0", path = "../sampo-core" }
 clap = { version = "4.5", features = ["derive"] }
 dialoguer = { version = "0.11", default-features = true }
+dirs = "6.0.0"
 
 [dev-dependencies]
 tempfile = "3"

crates/sampo/Cargo.toml

@@ -6,14 +6,18 @@ mod prerelease;
 mod publish;
 mod release;
 mod ui;
+mod version_check;
 
 use clap::Parser;
 use cli::{Cli, Commands};
 use std::process::ExitCode;
+use version_check::VersionCheckResult;
 
 fn main() -> ExitCode {
     let cli = Cli::parse();
 
+    check_and_notify_update();
+
     match cli.command {
         Commands::Init => {
             let cwd = match std::env::current_dir() {
@@ -70,3 +74,14 @@ fn main() -> ExitCode {
     }
     ExitCode::SUCCESS
 }
+
+/// Checks for CLI updates and prints a hint if a newer version is available. Non-blocking, best-effort.
+fn check_and_notify_update() {
+    if let VersionCheckResult::UpdateAvailable { current, latest } =
+        version_check::check_for_updates()
+    {
+        ui::log_hint(&format!(
+            "A new version of Sampo is available: {current} → {latest}. Run `cargo install sampo` to update."
+        ));
+    }
+}

crates/sampo/src/main.rs

@@ -10,7 +10,8 @@ use sampo_core::{
 use std::io;
 
 pub const SUCCESS_PREFIX: &str = "✔";
-pub const WARNING_PREFIX: &str = "⚠️";
+pub const WARNING_PREFIX: &str = "⚠";
+pub const HINT_PREFIX: &str = "💡";
 const EMPTY_SELECTION_PLACEHOLDER: &str = "(none)";
 
 pub fn log_success_value(label: &str, value: &str) {
@@ -55,6 +56,17 @@ pub fn log_warning(message: &str) {
     eprintln!("{line}");
 }
 
+/// Prints a hint message to stderr with a distinct visual style.
+///
+/// Used for non-critical suggestions like update notifications.
+pub fn log_hint(message: &str) {
+    let prefix = style(HINT_PREFIX.to_string()).for_stderr().yellow();
+    let message_style = Style::new().for_stderr().yellow();
+
+    let line = format!("{} {}", prefix, message_style.apply_to(message));
+    eprintln!("{line}");
+}
+
 pub fn prompt_theme() -> ColorfulTheme {
     ColorfulTheme {
         prompt_prefix: style("🧭".to_string()).cyan(),