diff --git a/tests/snapshots/output/changes,grid,header,numbers.snapshot.txt b/tests/snapshots/output/changes,grid,header,numbers.snapshot.txt
index b15296ee..81b292f8 100644
--- a/tests/snapshots/output/changes,grid,header,numbers.snapshot.txt
+++ b/tests/snapshots/output/changes,grid,header,numbers.snapshot.txt
@@ -13,13 +13,14 @@
   10 ~ │         "The perimeter of the rectangle is {} pixels.",
   11 ~ │         perimeter(&rect1)
   12   │     );
-  13   │ }
-  14   │ 
-  15   │ fn area(rectangle: &Rectangle) -> u32 {
-  16   │     rectangle.width * rectangle.height
-  17   │ }
-  18 + │ 
-  19 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 + │     (rectangle.width + rectangle.height) * 2
-  21 + │ }
+  13 + │ <bat: INVALID UTF-8>
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19 + │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
 ───────┴────────────────────────────────────────────────────────────────────────
diff --git a/tests/snapshots/output/changes,grid,header.snapshot.txt b/tests/snapshots/output/changes,grid,header.snapshot.txt
index cf739b4a..d5be34cb 100644
--- a/tests/snapshots/output/changes,grid,header.snapshot.txt
+++ b/tests/snapshots/output/changes,grid,header.snapshot.txt
@@ -13,6 +13,7 @@ _ │ fn main() {
 ~ │         "The perimeter of the rectangle is {} pixels.",
 ~ │         perimeter(&rect1)
   │     );
++ │ <bat: INVALID UTF-8>
   │ }
   │ 
   │ fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/changes,grid,numbers.snapshot.txt b/tests/snapshots/output/changes,grid,numbers.snapshot.txt
index fd078f3a..312fcd70 100644
--- a/tests/snapshots/output/changes,grid,numbers.snapshot.txt
+++ b/tests/snapshots/output/changes,grid,numbers.snapshot.txt
@@ -10,13 +10,14 @@
   10 ~ │         "The perimeter of the rectangle is {} pixels.",
   11 ~ │         perimeter(&rect1)
   12   │     );
-  13   │ }
-  14   │ 
-  15   │ fn area(rectangle: &Rectangle) -> u32 {
-  16   │     rectangle.width * rectangle.height
-  17   │ }
-  18 + │ 
-  19 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 + │     (rectangle.width + rectangle.height) * 2
-  21 + │ }
+  13 + │ <bat: INVALID UTF-8>
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19 + │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
 ───────┴────────────────────────────────────────────────────────────────────────
diff --git a/tests/snapshots/output/changes,grid.snapshot.txt b/tests/snapshots/output/changes,grid.snapshot.txt
index 8f20a69e..fc4f26c7 100644
--- a/tests/snapshots/output/changes,grid.snapshot.txt
+++ b/tests/snapshots/output/changes,grid.snapshot.txt
@@ -10,6 +10,7 @@ _ │ fn main() {
 ~ │         "The perimeter of the rectangle is {} pixels.",
 ~ │         perimeter(&rect1)
   │     );
++ │ <bat: INVALID UTF-8>
   │ }
   │ 
   │ fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/changes,header,numbers.snapshot.txt b/tests/snapshots/output/changes,header,numbers.snapshot.txt
index 1b190a19..60105755 100644
--- a/tests/snapshots/output/changes,header,numbers.snapshot.txt
+++ b/tests/snapshots/output/changes,header,numbers.snapshot.txt
@@ -11,12 +11,13 @@ File: sample.rs
   10 ~         "The perimeter of the rectangle is {} pixels.",
   11 ~         perimeter(&rect1)
   12       );
-  13   }
-  14   
-  15   fn area(rectangle: &Rectangle) -> u32 {
-  16       rectangle.width * rectangle.height
-  17   }
-  18 + 
-  19 + fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 +     (rectangle.width + rectangle.height) * 2
-  21 + }
+  13 + <bat: INVALID UTF-8>
+  14   }
+  15   
+  16   fn area(rectangle: &Rectangle) -> u32 {
+  17       rectangle.width * rectangle.height
+  18   }
+  19 + 
+  20 + fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 +     (rectangle.width + rectangle.height) * 2
+  22 + }
diff --git a/tests/snapshots/output/changes,header.snapshot.txt b/tests/snapshots/output/changes,header.snapshot.txt
index f914c95b..06be75d2 100644
--- a/tests/snapshots/output/changes,header.snapshot.txt
+++ b/tests/snapshots/output/changes,header.snapshot.txt
@@ -11,6 +11,7 @@ _ fn main() {
 ~         "The perimeter of the rectangle is {} pixels.",
 ~         perimeter(&rect1)
       );
++ <bat: INVALID UTF-8>
   }
   
   fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/changes,numbers.snapshot.txt b/tests/snapshots/output/changes,numbers.snapshot.txt
index eabb3c1c..391467f3 100644
--- a/tests/snapshots/output/changes,numbers.snapshot.txt
+++ b/tests/snapshots/output/changes,numbers.snapshot.txt
@@ -10,12 +10,13 @@
   10 ~         "The perimeter of the rectangle is {} pixels.",
   11 ~         perimeter(&rect1)
   12       );
-  13   }
-  14   
-  15   fn area(rectangle: &Rectangle) -> u32 {
-  16       rectangle.width * rectangle.height
-  17   }
-  18 + 
-  19 + fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 +     (rectangle.width + rectangle.height) * 2
-  21 + }
+  13 + <bat: INVALID UTF-8>
+  14   }
+  15   
+  16   fn area(rectangle: &Rectangle) -> u32 {
+  17       rectangle.width * rectangle.height
+  18   }
+  19 + 
+  20 + fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 +     (rectangle.width + rectangle.height) * 2
+  22 + }
diff --git a/tests/snapshots/output/changes.snapshot.txt b/tests/snapshots/output/changes.snapshot.txt
index 5695ea6b..13dabbdf 100644
--- a/tests/snapshots/output/changes.snapshot.txt
+++ b/tests/snapshots/output/changes.snapshot.txt
@@ -10,6 +10,7 @@ _ fn main() {
 ~         "The perimeter of the rectangle is {} pixels.",
 ~         perimeter(&rect1)
       );
++ <bat: INVALID UTF-8>
   }
   
   fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/full.snapshot.txt b/tests/snapshots/output/full.snapshot.txt
index b15296ee..81b292f8 100644
--- a/tests/snapshots/output/full.snapshot.txt
+++ b/tests/snapshots/output/full.snapshot.txt
@@ -13,13 +13,14 @@
   10 ~ │         "The perimeter of the rectangle is {} pixels.",
   11 ~ │         perimeter(&rect1)
   12   │     );
-  13   │ }
-  14   │ 
-  15   │ fn area(rectangle: &Rectangle) -> u32 {
-  16   │     rectangle.width * rectangle.height
-  17   │ }
-  18 + │ 
-  19 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 + │     (rectangle.width + rectangle.height) * 2
-  21 + │ }
+  13 + │ <bat: INVALID UTF-8>
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19 + │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
 ───────┴────────────────────────────────────────────────────────────────────────
diff --git a/tests/snapshots/output/grid,header,numbers.snapshot.txt b/tests/snapshots/output/grid,header,numbers.snapshot.txt
index 56696b17..d3dc664c 100644
--- a/tests/snapshots/output/grid,header,numbers.snapshot.txt
+++ b/tests/snapshots/output/grid,header,numbers.snapshot.txt
@@ -13,13 +13,14 @@
   10 │         "The perimeter of the rectangle is {} pixels.",
   11 │         perimeter(&rect1)
   12 │     );
-  13 │ }
-  14 │ 
-  15 │ fn area(rectangle: &Rectangle) -> u32 {
-  16 │     rectangle.width * rectangle.height
-  17 │ }
-  18 │ 
-  19 │ fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 │     (rectangle.width + rectangle.height) * 2
-  21 │ }
+  13 │ <bat: INVALID UTF-8>
+  14 │ }
+  15 │ 
+  16 │ fn area(rectangle: &Rectangle) -> u32 {
+  17 │     rectangle.width * rectangle.height
+  18 │ }
+  19 │ 
+  20 │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 │     (rectangle.width + rectangle.height) * 2
+  22 │ }
 ─────┴──────────────────────────────────────────────────────────────────────────
diff --git a/tests/snapshots/output/grid,header.snapshot.txt b/tests/snapshots/output/grid,header.snapshot.txt
index 781efb81..09766122 100644
--- a/tests/snapshots/output/grid,header.snapshot.txt
+++ b/tests/snapshots/output/grid,header.snapshot.txt
@@ -13,6 +13,7 @@ fn main() {
         "The perimeter of the rectangle is {} pixels.",
         perimeter(&rect1)
     );
+<bat: INVALID UTF-8>
 }
 
 fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/grid,numbers.snapshot.txt b/tests/snapshots/output/grid,numbers.snapshot.txt
index 2a76f8d3..6e877f59 100644
--- a/tests/snapshots/output/grid,numbers.snapshot.txt
+++ b/tests/snapshots/output/grid,numbers.snapshot.txt
@@ -10,13 +10,14 @@
   10 │         "The perimeter of the rectangle is {} pixels.",
   11 │         perimeter(&rect1)
   12 │     );
-  13 │ }
-  14 │ 
-  15 │ fn area(rectangle: &Rectangle) -> u32 {
-  16 │     rectangle.width * rectangle.height
-  17 │ }
-  18 │ 
-  19 │ fn perimeter(rectangle: &Rectangle) -> u32 {
-  20 │     (rectangle.width + rectangle.height) * 2
-  21 │ }
+  13 │ <bat: INVALID UTF-8>
+  14 │ }
+  15 │ 
+  16 │ fn area(rectangle: &Rectangle) -> u32 {
+  17 │     rectangle.width * rectangle.height
+  18 │ }
+  19 │ 
+  20 │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 │     (rectangle.width + rectangle.height) * 2
+  22 │ }
 ─────┴──────────────────────────────────────────────────────────────────────────
diff --git a/tests/snapshots/output/grid.snapshot.txt b/tests/snapshots/output/grid.snapshot.txt
index b5bd13c2..54c668f7 100644
--- a/tests/snapshots/output/grid.snapshot.txt
+++ b/tests/snapshots/output/grid.snapshot.txt
@@ -10,6 +10,7 @@ fn main() {
         "The perimeter of the rectangle is {} pixels.",
         perimeter(&rect1)
     );
+<bat: INVALID UTF-8>
 }
 
 fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/header,numbers.snapshot.txt b/tests/snapshots/output/header,numbers.snapshot.txt
index c1dcf63a..37d117ec 100644
--- a/tests/snapshots/output/header,numbers.snapshot.txt
+++ b/tests/snapshots/output/header,numbers.snapshot.txt
@@ -11,12 +11,13 @@ File: sample.rs
   10         "The perimeter of the rectangle is {} pixels.",
   11         perimeter(&rect1)
   12     );
-  13 }
-  14 
-  15 fn area(rectangle: &Rectangle) -> u32 {
-  16     rectangle.width * rectangle.height
-  17 }
-  18 
-  19 fn perimeter(rectangle: &Rectangle) -> u32 {
-  20     (rectangle.width + rectangle.height) * 2
-  21 }
+  13 <bat: INVALID UTF-8>
+  14 }
+  15 
+  16 fn area(rectangle: &Rectangle) -> u32 {
+  17     rectangle.width * rectangle.height
+  18 }
+  19 
+  20 fn perimeter(rectangle: &Rectangle) -> u32 {
+  21     (rectangle.width + rectangle.height) * 2
+  22 }
diff --git a/tests/snapshots/output/header.snapshot.txt b/tests/snapshots/output/header.snapshot.txt
index d0e167a9..041640b6 100644
--- a/tests/snapshots/output/header.snapshot.txt
+++ b/tests/snapshots/output/header.snapshot.txt
@@ -11,6 +11,7 @@ fn main() {
         "The perimeter of the rectangle is {} pixels.",
         perimeter(&rect1)
     );
+<bat: INVALID UTF-8>
 }
 
 fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/output/numbers.snapshot.txt b/tests/snapshots/output/numbers.snapshot.txt
index 198f0355..9d4b6ba2 100644
--- a/tests/snapshots/output/numbers.snapshot.txt
+++ b/tests/snapshots/output/numbers.snapshot.txt
@@ -10,12 +10,13 @@
   10         "The perimeter of the rectangle is {} pixels.",
   11         perimeter(&rect1)
   12     );
-  13 }
-  14 
-  15 fn area(rectangle: &Rectangle) -> u32 {
-  16     rectangle.width * rectangle.height
-  17 }
-  18 
-  19 fn perimeter(rectangle: &Rectangle) -> u32 {
-  20     (rectangle.width + rectangle.height) * 2
-  21 }
+  13 <bat: INVALID UTF-8>
+  14 }
+  15 
+  16 fn area(rectangle: &Rectangle) -> u32 {
+  17     rectangle.width * rectangle.height
+  18 }
+  19 
+  20 fn perimeter(rectangle: &Rectangle) -> u32 {
+  21     (rectangle.width + rectangle.height) * 2
+  22 }
diff --git a/tests/snapshots/output/plain.snapshot.txt b/tests/snapshots/output/plain.snapshot.txt
index d66799f0..9bfc0d1b 100644
--- a/tests/snapshots/output/plain.snapshot.txt
+++ b/tests/snapshots/output/plain.snapshot.txt
@@ -10,6 +10,7 @@ fn main() {
         "The perimeter of the rectangle is {} pixels.",
         perimeter(&rect1)
     );
+<bat: INVALID UTF-8>
 }
 
 fn area(rectangle: &Rectangle) -> u32 {
diff --git a/tests/snapshots/sample.modified.rs b/tests/snapshots/sample.modified.rs
index d66799f0..bb1a7943 100644
--- a/tests/snapshots/sample.modified.rs
+++ b/tests/snapshots/sample.modified.rs
@@ -10,6 +10,7 @@ fn main() {
         "The perimeter of the rectangle is {} pixels.",
         perimeter(&rect1)
     );
+    println!(r#"This line contains invalid utf8:  "øˆ€€€"#;
 }
 
 fn area(rectangle: &Rectangle) -> u32 {