Add tests for the rectangles project

rectangles/src/main.rs

@@ -11,8 +11,31 @@ impl Rectangle {
             height: size,
         }
     }
+
+    fn can_hold(&self, other: &Rectangle) -> bool {
+        self.width > other.width && self.height > other.height
+    }
 }
 
 fn main() {
     let sq = Rectangle::square(3);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn larger_can_hold_smaller() {
+        let larger = Rectangle {
+            width: 8,
+            height: 7,
+        };
+        let smaller = Rectangle {
+            width: 5,
+            height: 1,
+        };
+
+        assert!(larger.can_hold(&smaller));
+    }
+}