diff --git a/src/help.rs b/src/help.rs
index 6ad983a6c..5141d6edf 100644
--- a/src/help.rs
+++ b/src/help.rs
@@ -35,7 +35,7 @@ mod tests {
 	use super::*;
 
 	#[test]
-	fn test_run() {
+	fn run_success() {
 		assert!(
 			run()
 				.get_message()
diff --git a/src/license.rs b/src/license.rs
index a32fe4503..19d2a734a 100644
--- a/src/license.rs
+++ b/src/license.rs
@@ -31,7 +31,7 @@ mod tests {
 	use super::*;
 
 	#[test]
-	fn test_run() {
+	fn run_success() {
 		assert!(
 			run()
 				.get_message()
diff --git a/src/modules/external_editor/argument_tokenizer.rs b/src/modules/external_editor/argument_tokenizer.rs
index 5f148d093..ece17c7ee 100644
--- a/src/modules/external_editor/argument_tokenizer.rs
+++ b/src/modules/external_editor/argument_tokenizer.rs
@@ -19,7 +19,7 @@ pub(super) fn tokenize(input: &str) -> Option<Vec<String>> {
 	let mut force_value = false;
 
 	let mut tokens = vec![];
-	for (i, c) in input.chars().enumerate() {
+	for (i, c) in input.char_indices() {
 		match state {
 			State::Normal => {
 				if c == '\\' {
diff --git a/src/version.rs b/src/version.rs
index e92dd4d25..a99f591b7 100644
--- a/src/version.rs
+++ b/src/version.rs
@@ -27,7 +27,7 @@ mod tests {
 
 	#[test]
 	#[serial_test::serial]
-	fn test_run() {
+	fn run_success() {
 		assert!(run().get_message().unwrap().starts_with("interactive-rebase-tool"));
 	}
 
diff --git a/src/view/render_slice.rs b/src/view/render_slice.rs
index 6f1f08cc3..529b5ecd3 100644
--- a/src/view/render_slice.rs
+++ b/src/view/render_slice.rs
@@ -130,12 +130,7 @@ impl RenderSlice {
 			return 0;
 		}
 
-		let view_height = if self.padding_height < self.height {
-			self.height - self.padding_height
-		}
-		else {
-			0
-		};
+		let view_height = self.height.saturating_sub(self.padding_height);
 
 		if view_height <= 1 || view_height > self.lines_count {
 			return 0;
@@ -285,12 +280,8 @@ impl RenderSlice {
 		else {
 			// trailing lines have precedence over leading lines, title always has precedence
 			let padding_height = if self.show_title { 1 } else { 0 } + trailing_lines_length;
-			let available_height = if padding_height < self.height {
-				self.height - padding_height
-			}
-			else {
-				0
-			};
+			let available_height = self.height.saturating_sub(padding_height);
+
 			let leading_lines_end = if leading_lines_length < available_height {
 				leading_lines_length
 			}
@@ -310,12 +301,7 @@ impl RenderSlice {
 		else {
 			// title always has precedence
 			let padding_height = if self.show_title { 1 } else { 0 };
-			let available_height = if padding_height < self.height {
-				self.height - padding_height
-			}
-			else {
-				0
-			};
+			let available_height = self.height.saturating_sub(padding_height);
 
 			let trailing_lines_end = if trailing_lines_length < available_height {
 				trailing_lines_length
@@ -335,12 +321,7 @@ impl RenderSlice {
 		}
 		else {
 			// all other lines take precedence over regular lines
-			let available_height = if self.padding_height < self.height {
-				self.height - self.padding_height
-			}
-			else {
-				0
-			};
+			let available_height = self.height.saturating_sub(self.padding_height);
 
 			let lines_start = self.scroll_position.get_top_position();