make git commit hash available at compile time

build.rs

@@ -0,0 +1,7 @@
+use std::process::Command;
+
+fn main() {
+    let output = Command::new("git").args(&["rev-parse", "--short",  "HEAD"]).output().unwrap();
+    let git_hash = String::from_utf8(output.stdout).unwrap();
+    println!("cargo:rustc-env=GIT_HASH={}", git_hash);
+}

src/artifacts.rs

@@ -68,8 +68,11 @@ impl Artifact for Potion {
     }
     fn get_immutable_position(&self) -> &Position { &self.position }
     fn collect(&mut self, player: &mut Player) {
-        player.change_life(self.health.try_into().unwrap());
-        self.health = 0;
+        // only consume potion of the player can gain at least one health point
+        if !player.is_healthy() {
+            player.change_life(self.health.try_into().unwrap());
+            self.health = 0;
+        }
     }
 
     fn was_collected(&self) -> bool {

src/main.rs

@@ -160,6 +160,7 @@ fn main() -> Result<()> {
             text += format!("\nYou gained {} experience.", game.get_player().get_experience()).as_str();
             text += format!("\nYou collected {} gold.", game.get_player().get_gold()).as_str();
             text += format!("\nYou played {} seconds.", playtime.as_secs()).as_str();
+            text += format!("\nYou played game version '{}'.", env!("GIT_HASH")).as_str();
             let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: true });
             frame.render_widget(paragraph, area);
         });
@@ -171,7 +172,6 @@ fn main() -> Result<()> {
             }
         }
     }
-
     stdout().execute(LeaveAlternateScreen)?;
     disable_raw_mode()?;
     Ok(())

src/player.rs

@@ -28,11 +28,13 @@ impl Player {
     pub fn change_life(&mut self, by: i16) {
         self.life = max(0, min(self.max_life, self.life + by));
     }
-    /// returns true if the player is dead (life <= 0)
     pub fn get_life(&self) -> i16 {
         self.life
     }
+    /// returns true if the player is dead (life <= 0)
     pub fn is_dead(&self) -> bool { self.life <= 0 }
+    /// returns true if the player's life is at maximum
+    pub fn is_healthy(&self) -> bool { self.life == self.max_life }
     pub fn get_max_life(&self) -> i16 {
         self.max_life
     }