diff --git a/src/input.rs b/src/input.rs
index 2f58fa9..c7a1484 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -82,65 +82,3 @@ impl App {
         }
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn replace<'a>(
-        look_for: impl Into<String>,
-        replace_with: impl Into<String>,
-        literal: bool,
-        flags: Option<&'static str>,
-        src: &'static str,
-        target: &'static str,
-    ) {
-        let replacer = Replacer::new(
-            look_for.into(),
-            replace_with.into(),
-            literal,
-            flags.map(ToOwned::to_owned),
-        )
-        .unwrap();
-        assert_eq!(
-            std::str::from_utf8(&replacer.replace(src.as_bytes())),
-            Ok(target)
-        );
-    }
-
-    #[test]
-    fn default_global() {
-        replace("a", "b", false, None, "aaa", "bbb");
-    }
-
-    #[test]
-    fn escaped_char_preservation() {
-        replace("a", "b", false, None, "a\\n", "b\\n");
-    }
-
-    #[test]
-    fn case_sensitive_default() {
-        replace("abc", "x", false, None, "abcABC", "xABC");
-        replace("abc", "x", true, None, "abcABC", "xABC");
-    }
-
-    #[test]
-    fn sanity_check_literal_replacements() {
-        replace("((special[]))", "x", true, None, "((special[]))y", "xy");
-    }
-
-    #[test]
-    fn unescape_regex_replacements() {
-        replace("test", r"\n", false, None, "testtest", "\n\n");
-    }
-
-    #[test]
-    fn no_unescape_literal_replacements() {
-        replace("test", r"\n", true, None, "testtest", r"\n\n");
-    }
-
-    #[test]
-    fn full_word_replace() {
-        replace("abc", "def", false, Some("w"), "abcd abc", "abcd def");
-    }
-}
diff --git a/src/replacer.rs b/src/replacer.rs
index 367de0c..1ecb1a4 100644
--- a/src/replacer.rs
+++ b/src/replacer.rs
@@ -71,7 +71,10 @@ impl Replacer {
         Ok(())
     }
 
-    pub(crate) fn replace<'a>(&'a self, content: &'a [u8]) -> std::borrow::Cow<'a, [u8]> {
+    pub(crate) fn replace<'a>(
+        &'a self,
+        content: &'a [u8],
+    ) -> std::borrow::Cow<'a, [u8]> {
         if self.is_literal {
             self.regex.replace_all(
                 &content,
@@ -116,3 +119,66 @@ impl Replacer {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn replace<'a>(
+        look_for: impl Into<String>,
+        replace_with: impl Into<String>,
+        literal: bool,
+        flags: Option<&'static str>,
+        src: &'static str,
+        target: &'static str,
+    ) {
+        let replacer = Replacer::new(
+            look_for.into(),
+            replace_with.into(),
+            literal,
+            flags.map(ToOwned::to_owned),
+        )
+        .unwrap();
+        assert_eq!(
+            std::str::from_utf8(&replacer.replace(src.as_bytes())),
+            Ok(target)
+        );
+    }
+
+    #[test]
+    fn default_global() {
+        replace("a", "b", false, None, "aaa", "bbb");
+    }
+
+    #[test]
+    fn escaped_char_preservation() {
+        replace("a", "b", false, None, "a\\n", "b\\n");
+    }
+
+    #[test]
+    fn case_sensitive_default() {
+        replace("abc", "x", false, None, "abcABC", "xABC");
+        replace("abc", "x", true, None, "abcABC", "xABC");
+    }
+
+    #[test]
+    fn sanity_check_literal_replacements() {
+        replace("((special[]))", "x", true, None, "((special[]))y", "xy");
+    }
+
+    #[test]
+    fn unescape_regex_replacements() {
+        replace("test", r"\n", false, None, "testtest", "\n\n");
+    }
+
+    #[test]
+    fn no_unescape_literal_replacements() {
+        replace("test", r"\n", true, None, "testtest", r"\n\n");
+    }
+
+    #[test]
+    fn full_word_replace() {
+        replace("abc", "def", false, Some("w"), "abcd abc", "abcd def");
+    }
+}
+