Pass pre-painted prefix as Option

4 files changed, 36 insertions, 44 deletions

diff --git a/src/delta.rs b/src/delta.rs
index ff1edef8..bbb7a9ce 100644
--- a/src/delta.rs
+++ b/src/delta.rs
@@ -456,7 +456,7 @@ fn handle_hunk_header_line(
                 &mut painter.output_buffer,
                 config,
                 &mut None,
-                &config.null_style.paint(""),
+                None,
                 None,
                 Some(false),
             );
diff --git a/src/features/side_by_side.rs b/src/features/side_by_side.rs
index ea8aabef..f4680898 100644
--- a/src/features/side_by_side.rs
+++ b/src/features/side_by_side.rs
@@ -83,11 +83,11 @@ pub fn paint_minus_and_plus_lines_side_by_side<'a>(
                 None => &State::HunkMinus(None),
             },
             line_numbers_data,
-            &config.minus_style.paint(if config.keep_plus_minus_markers {
-                "-"
+            if config.keep_plus_minus_markers {
+                Some(config.minus_style.paint("-"))
             } else {
-                ""
-            }),
+                None
+            },
             background_color_extends_to_terminal_width,
             config,
         ));
@@ -100,11 +100,11 @@ pub fn paint_minus_and_plus_lines_side_by_side<'a>(
                 None => &State::HunkPlus(None),
             },
             line_numbers_data,
-            &config.plus_style.paint(if config.keep_plus_minus_markers {
-                "+"
+            if config.keep_plus_minus_markers {
+                Some(config.plus_style.paint("+"))
             } else {
-                ""
-            }),
+                None
+            },
             background_color_extends_to_terminal_width,
             config,
         ));
@@ -120,7 +120,7 @@ pub fn paint_zero_lines_side_by_side(
     output_buffer: &mut String,
     config: &Config,
     line_numbers_data: &mut Option<&mut line_numbers::LineNumbersData>,
-    painted_prefix: &ansi_term::ANSIString,
+    painted_prefix: Option<ansi_term::ANSIString>,
     background_color_extends_to_terminal_width: Option<bool>,
 ) {
     for (line_index, (syntax_sections, diff_sections)) in syntax_style_sections
@@ -134,7 +134,7 @@ pub fn paint_zero_lines_side_by_side(
             state,
             line_numbers_data,
             Some(PanelSide::Left),
-            painted_prefix,
+            painted_prefix.clone(),
             config,
         );
         // TODO: Avoid doing the superimpose_style_sections work twice.
@@ -160,7 +160,7 @@ pub fn paint_zero_lines_side_by_side(
             state,
             line_numbers_data,
             Some(PanelSide::Right),
-            painted_prefix,
+            painted_prefix.clone(),
             config,
         );
         right_fill_right_panel_line(
@@ -184,7 +184,7 @@ fn paint_left_panel_minus_line<'a>(
     diff_style_sections: &[Vec<(Style, &str)>],
     state: &'a State,
     line_numbers_data: &mut Option<&mut line_numbers::LineNumbersData>,
-    painted_prefix: &ansi_term::ANSIString,
+    painted_prefix: Option<ansi_term::ANSIString>,
     background_color_extends_to_terminal_width: Option<bool>,
     config: &Config,
 ) -> String {
@@ -218,7 +218,7 @@ fn paint_right_panel_plus_line<'a>(
     diff_style_sections: &[Vec<(Style, &str)>],
     state: &'a State,
     line_numbers_data: &mut Option<&mut line_numbers::LineNumbersData>,
-    painted_prefix: &ansi_term::ANSIString,
+    painted_prefix: Option<ansi_term::ANSIString>,
     background_color_extends_to_terminal_width: Option<bool>,
     config: &Config,
 ) -> String {
@@ -301,7 +301,7 @@ fn paint_minus_or_plus_panel_line(
     state: &State,
     line_numbers_data: &mut Option<&mut line_numbers::LineNumbersData>,
     panel_side: PanelSide,
-    painted_prefix: &ansi_term::ANSIString,
+    painted_prefix: Option<ansi_term::ANSIString>,
     config: &Config,
 ) -> (String, bool) {
     let (empty_line_syntax_sections, empty_line_diff_sections) = (Vec::new(), Vec::new());
diff --git a/src/paint.rs b/src/paint.rs
index 438f671b..bbff5a8b 100644
--- a/src/paint.rs
+++ b/src/paint.rs
@@ -163,14 +163,11 @@ impl<'a> Painter<'a> {
                     &mut self.output_buffer,
                     self.config,
                     &mut Some(&mut self.line_numbers_data),
-                    &self
-                        .config
-                        .minus_style
-                        .paint(if self.config.keep_plus_minus_markers {
-                            "-"
-                        } else {
-                            ""
-                        }),
+                    if self.config.keep_plus_minus_markers {
+                        Some(self.config.minus_style.paint("-"))
+                    } else {
+                        None
+                    },
                     Some(self.config.minus_empty_line_marker_style),
                     None,
                 );
@@ -183,14 +180,11 @@ impl<'a> Painter<'a> {
                     &mut self.output_buffer,
                     self.config,
                     &mut Some(&mut self.line_numbers_data),
-                    &self
-                        .config
-                        .plus_style
-                        .paint(if self.config.keep_plus_minus_markers {
-                            "+"
-                        } else {
-                            ""
-                        }),
+                    if self.config.keep_plus_minus_markers {
+                        Some(self.config.plus_style.paint("+"))
+                    } else {
+                        None
+                    },
                     Some(self.config.plus_empty_line_marker_style),
                     None,
                 );
@@ -202,13 +196,11 @@ impl<'a> Painter<'a> {
 
     pub fn paint_zero_line(&mut self, line: &str) {
         let state = State::HunkZero;
-        let painted_prefix = &self.config.zero_style.paint(
-            if self.config.keep_plus_minus_markers && !line.is_empty() {
-                &line[..1]
-            } else {
-                ""
-            },
-        );
+        let painted_prefix = if self.config.keep_plus_minus_markers && !line.is_empty() {
+            Some(self.config.zero_style.paint(&line[..1]))
+        } else {
+            None
+        };
         let lines = vec![(self.prepare(line, true), state.clone())];
         let syntax_style_sections = Painter::get_syntax_style_sections_for_lines(
             &lines,
@@ -254,7 +246,7 @@ impl<'a> Painter<'a> {
         output_buffer: &mut String,
         config: &config::Config,
         line_numbers_data: &mut Option<&mut line_numbers::LineNumbersData>,
-        painted_prefix: &ansi_term::ANSIString,
+        painted_prefix: Option<ansi_term::ANSIString>,
         empty_line_style: Option<Style>, // a style with background color to highlight an empty line
         background_color_extends_to_terminal_width: Option<bool>,
     ) {
@@ -276,7 +268,7 @@ impl<'a> Painter<'a> {
                 state,
                 line_numbers_data,
                 None,
-                painted_prefix,
+                painted_prefix.clone(),
                 config,
             );
             let (should_right_fill_background_color, fill_style) =
@@ -387,7 +379,7 @@ impl<'a> Painter<'a> {
         state: &State,
         line_numbers_data: &mut Option<&mut line_numbers::LineNumbersData>,
         side_by_side_panel: Option<side_by_side::PanelSide>,
-        painted_prefix: &ansi_term::ANSIString,
+        painted_prefix: Option<ansi_term::ANSIString>,
         config: &config::Config,
     ) -> (String, bool) {
         let output_line_numbers = config.line_numbers && line_numbers_data.is_some();
@@ -424,8 +416,8 @@ impl<'a> Painter<'a> {
             config.null_syntect_style,
         ) {
             if !handled_prefix {
-                if &**painted_prefix != "" {
-                    ansi_strings.push(painted_prefix.clone());
+                if let Some(painted_prefix) = painted_prefix.clone() {
+                    ansi_strings.push(painted_prefix);
                 }
                 if !text.is_empty() {
                     text.remove(0);
diff --git a/src/tests/ansi_test_utils.rs b/src/tests/ansi_test_utils.rs
index e7b25e47..d0456d92 100644
--- a/src/tests/ansi_test_utils.rs
+++ b/src/tests/ansi_test_utils.rs
@@ -145,7 +145,7 @@ pub mod ansi_test_utils {
             &mut output_buffer,
             config,
             &mut None,
-            &config.null_style.paint(prefix),
+            Some(config.null_style.paint(prefix)),
             None,
             None,
         );