test: ensure startup message is correct

src/branding.rs

@@ -1,8 +1,18 @@
-pub fn startup_msg() {
+#[cfg(test)]
+use insta::assert_snapshot;
+
+pub fn startup_msg() -> String {
     let name = env!("CARGO_PKG_NAME");
     let version = env!("CARGO_PKG_VERSION");
     let authors = env!("CARGO_PKG_AUTHORS");
 
-    println!("{name} v{version} started.",);
-    println!("Copyright 2025 {authors}. All rights reserved.")
+    format!(
+        "{name} v{version} started.\n\
+        Copyright 2025 {authors}. All rights reserved."
+    )
+}
+
+#[test]
+fn test_startup_msg() {
+    assert_snapshot!(startup_msg())
 }

src/main.rs

@@ -4,7 +4,7 @@ use osdb::command::Command;
 use osdb::error_display::OSDBError as _;
 
 fn main() {
-    startup_msg();
+    println!("{}", startup_msg());
     while let Some(input) = read_input() {
         match input.parse::<Command>() {
             Ok(cmd) => {

src/snapshots/osdb__branding__startup_msg.snap

@@ -0,0 +1,6 @@
+---
+source: src/branding.rs
+expression: startup_msg()
+---
+osdb v0.1.0 started.
+Copyright 2025 Khaïs COLIN. All rights reserved.