fix: move the testing macro out

Signed-off-by: Matej Focko <mfocko@redhat.com>

src/solution.rs

@@ -63,27 +63,3 @@ pub trait Solution<Output1: Display, Output2: Display> {
         Self::run("input")
     }
 }
-
-#[macro_export]
-macro_rules! test_sample {
-    ($mod_name:ident, $day_struct:tt, $part_1:expr, $part_2:expr) => {
-        #[cfg(test)]
-        mod $mod_name {
-            use super::*;
-
-            #[test]
-            fn part_1() {
-                let path = $day_struct::get_sample(1);
-                let mut day = $day_struct::new(path);
-                assert_eq!(day.part_1(), $part_1);
-            }
-
-            #[test]
-            fn part_2() {
-                let path = $day_struct::get_sample(2);
-                let mut day = $day_struct::new(path);
-                assert_eq!(day.part_2(), $part_2);
-            }
-        }
-    };
-}

src/testing.rs

@@ -1 +1,25 @@
+//! # Testing-related utilities
 
+#[macro_export]
+macro_rules! test_sample {
+    ($mod_name:ident, $day_struct:tt, $part_1:expr, $part_2:expr) => {
+        #[cfg(test)]
+        mod $mod_name {
+            use super::*;
+
+            #[test]
+            fn part_1() {
+                let path = $day_struct::get_sample(1);
+                let mut day = $day_struct::new(path);
+                assert_eq!(day.part_1(), $part_1);
+            }
+
+            #[test]
+            fn part_2() {
+                let path = $day_struct::get_sample(2);
+                let mut day = $day_struct::new(path);
+                assert_eq!(day.part_2(), $part_2);
+            }
+        }
+    };
+}