Add board module

src/board.rs

+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Square {
+    Empty,
+    Cross,
+    Circle,
+}
+
+impl std::fmt::Display for Square {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Square::Empty => write!(f, "."),
+            Square::Cross => write!(f, "X"),
+            Square::Circle => write!(f, "O"),
+        }
+    }
+}
+
+pub struct Board {
+    board: [Square; 9],
+}
+
+impl Board {
+    /// Creates a new empty board
+    pub fn new() -> Self {
+        Self {
+            board: [Square::Empty; 9],
+        }
+    }
+
+    /// Display the board to standard output
+    pub fn display(&self) {
+        println!("{}", self);
+    }
+}
+
+impl std::fmt::Display for Board {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        for row in 0..3 {
+            writeln!(f, " {} | {} | {}",
+                    self.board[row * 3],
+                    self.board[row * 3 + 1],
+                    self.board[row * 3 + 2],
+                )?;
+            if row == 0 || row == 1 {
+                writeln!(f, "---+---+---")?;
+            }
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    
+    #[test]
+    fn new_board_squares_are_empty() {
+        let board = Board::new();
+
+        for square in board.board {
+            assert_eq!(square, Square::Empty);
+        }
+    }
+
+    #[test]
+    fn empty_board_to_string() {
+        let expected = " . | . | .
+---+---+---
+ . | . | .
+---+---+---
+ . | . | .
+";
+        assert_eq!(expected, format!("{}", Board::new()));
+    }
+
+    #[test]
+    fn empty_square_to_string_dot() {
+        assert_eq!(".", format!("{}", Square::Empty));
+    }
+    #[test]
+    fn cross_square_to_string_x() {
+        assert_eq!("X", format!("{}", Square::Cross));
+    }
+    #[test]
+    fn circle_square_to_string_big_o() {
+        assert_eq!("O", format!("{}", Square::Circle));
+    }
+
+}

src/main.rs

-#[derive(Clone, Copy, Debug, PartialEq)]
-enum Square {
-    Empty,
-    Cross,
-    Circle,
-}
-
-impl std::fmt::Display for Square {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Square::Empty => write!(f, "."),
-            Square::Cross => write!(f, "X"),
-            Square::Circle => write!(f, "O"),
-        }
-    }
-}
+mod board;
 
-struct Board {
-    board: [Square; 9],
-}
-
-impl Board {
-    /// Creates a new empty board
-    fn new() -> Self {
-        Self {
-            board: [Square::Empty; 9],
-        }
-    }
-
-    /// Display the board to standard output
-    fn display(&self) {
-        println!("{}", self);
-    }
-}
-
-impl std::fmt::Display for Board {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        for row in 0..3 {
-            writeln!(f, " {} | {} | {}",
-                    self.board[row * 3],
-                    self.board[row * 3 + 1],
-                    self.board[row * 3 + 2],
-                )?;
-            if row == 0 || row == 1 {
-                writeln!(f, "---+---+---")?;
-            }
-        }
-        Ok(())
-    }
-}
+use board::Board;
     
 fn main() {
     let board = Board::new();
@@ -59,8 +12,6 @@ fn main() {
 #[cfg(test)]
 // A module where the tests are located, more on modules later
 mod tests {
-    use super::*;
-
     #[test]
     fn should_pass() {
         assert!(true);
@@ -70,37 +21,4 @@ mod tests {
     fn should_panic() {
         panic!("Doing wrong things on purpose here!");
     }
-
-    #[test]
-    fn new_board_squares_are_empty() {
-        let board = Board::new();
-
-        for square in board.board {
-            assert_eq!(square, Square::Empty);
-        }
-    }
-
-    #[test]
-    fn empty_board_to_string() {
-        let expected = " . | . | .
----+---+---
- . | . | .
----+---+---
- . | . | .
-";
-        assert_eq!(expected, format!("{}", Board::new()));
-    }
-
-    #[test]
-    fn empty_square_to_string_dot() {
-        assert_eq!(".", format!("{}", Square::Empty));
-    }
-    #[test]
-    fn cross_square_to_string_x() {
-        assert_eq!("X", format!("{}", Square::Cross));
-    }
-    #[test]
-    fn circle_square_to_string_big_o() {
-        assert_eq!("O", format!("{}", Square::Circle));
-    }
 }