Add additional helper functions to test if the tiles are aligned or not

board-shared/src/board.rs

@@ -1,4 +1,4 @@
-use crate::position::{Grid2d, Position2d};
+use crate::position::{Alignment, Grid2d, Position2d};
 use crate::tile::Tile;
 
 const DEFAULT_BOARD_SIZE: usize = 25;
@@ -55,6 +55,23 @@ impl Board {
 
         Some(true)
     }
+
+    /// Determines whether the given positions are aligned.
+    pub fn is_aligned(positions: &[Position2d], alignement: Alignment) -> bool {
+        if let Some(&first) = positions.first() {
+            positions
+                .iter()
+                .all(|&pos| alignement.is_aligned(first, pos))
+        } else {
+            true
+        }
+    }
+
+    /// Determines whether the given positions have any alignment.
+    pub fn has_alignment(positions: &[Position2d]) -> bool {
+        Self::is_aligned(positions, Alignment::Horizontal)
+            || Self::is_aligned(positions, Alignment::Vertical)
+    }
 }
 
 impl Grid2d for Board {
@@ -120,4 +137,34 @@ mod tests {
             Some(false)
         );
     }
+
+    #[test]
+    fn test_is_aligned() {
+        assert!(Board::is_aligned(&[], Alignment::Horizontal));
+        assert!(Board::is_aligned(&[], Alignment::Vertical));
+        assert!(Board::is_aligned(
+            &positions(&[(0, 0)]),
+            Alignment::Horizontal
+        ));
+        assert!(Board::is_aligned(
+            &positions(&[(0, 0)]),
+            Alignment::Vertical
+        ));
+        assert!(Board::is_aligned(
+            &positions(&[(0, 0), (0, 1)]),
+            Alignment::Horizontal
+        ));
+        assert!(Board::is_aligned(
+            &positions(&[(0, 0), (1, 0)]),
+            Alignment::Vertical
+        ));
+        assert!(!Board::is_aligned(
+            &positions(&[(0, 0), (1, 0)]),
+            Alignment::Horizontal
+        ));
+        assert!(!Board::is_aligned(
+            &positions(&[(0, 0), (0, 1)]),
+            Alignment::Vertical
+        ));
+    }
 }