Add banner implementation for the opts struct w/tests

1 files changed, 43 insertions, 0 deletions

diff --git a/CLI/rust/src/game_of_life/opts.rs b/CLI/rust/src/game_of_life/opts.rs
index 09e49c9..4a0d009 100644
--- a/CLI/rust/src/game_of_life/opts.rs
+++ b/CLI/rust/src/game_of_life/opts.rs
@@ -71,6 +71,14 @@ impl Opts {
             delay,
         })
     }
+
+    /// Print out the Banner info about used input or fallback to show the seed.
+    pub fn banner(&self) -> String {
+        match &self.input {
+            Some(i) => format!("Input: {}", &i),
+            None => format!("Seed: {}", &self.seed),
+        }
+    }
 }
 
 #[cfg(test)]
@@ -173,3 +181,38 @@ mod from {
         assert_eq!(opts.delay, 13);
     }
 }
+
+#[cfg(test)]
+mod banner {
+    use super::*;
+
+    #[test]
+    fn with_input() {
+        let opts = Opts {
+            input: Some(String::from("./file")),
+            seed: 1337,
+            width: 4,
+            height: 3,
+            live_cell: 'L',
+            dead_cell: 'D',
+            delay: 13,
+        };
+
+        assert_eq!(opts.banner(), "Input: ./file");
+    }
+
+    #[test]
+    fn without_input() {
+        let opts = Opts {
+            input: None,
+            seed: 1337,
+            width: 4,
+            height: 3,
+            live_cell: 'L',
+            dead_cell: 'D',
+            delay: 13,
+        };
+
+        assert_eq!(opts.banner(), "Seed: 1337");
+    }
+}