formatter: add support for underlined text

CHANGELOG.md

@@ -42,8 +42,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * The `ui.relative-timestamps` option now also affects `jj op log`.
 
-* Background colors and bold text are now supported. You can set e.g.
-  `color.error = { bg = "red", bold = true }` in your `~/.jjconfig.toml`.
+* Background colors, bold text, and underlining are now supported. You can set
+  e.g. `color.error = { bg = "red", bold = true, underline = true }` in your
+  `~/.jjconfig.toml`.
 
 ### Fixed bugs
 

src/formatter.rs

@@ -155,6 +155,7 @@ pub struct Style {
     pub fg_color: Option<Color>,
     pub bg_color: Option<Color>,
     pub bold: Option<bool>,
+    pub underlined: Option<bool>,
 }
 
 impl Style {
@@ -162,6 +163,7 @@ impl Style {
         self.fg_color = other.fg_color.or(self.fg_color);
         self.bg_color = other.bg_color.or(self.bg_color);
         self.bold = other.bold.or(self.bold);
+        self.underlined = other.underlined.or(self.underlined);
     }
 }
 
@@ -243,6 +245,13 @@ impl<W: Write> ColorFormatter<W> {
                     self.current_style = Style::default();
                 }
             }
+            if new_style.underlined != self.current_style.underlined {
+                if new_style.underlined.unwrap_or_default() {
+                    queue!(self.output, SetAttribute(Attribute::Underlined))?;
+                } else {
+                    queue!(self.output, SetAttribute(Attribute::NoUnderline))?;
+                }
+            }
             if new_style.fg_color != self.current_style.fg_color {
                 queue!(
                     self.output,
@@ -275,6 +284,7 @@ fn rules_from_config(config: &config::Config) -> HashMap<Vec<String>, Style> {
                         fg_color: color_for_name(&color_name),
                         bg_color: None,
                         bold: None,
+                        underlined: None,
                     };
                     result.insert(labels, style);
                 }
@@ -295,6 +305,11 @@ fn rules_from_config(config: &config::Config) -> HashMap<Vec<String>, Style> {
                             style.bold = Some(*value);
                         }
                     }
+                    if let Some(value) = style_table.get("underlined") {
+                        if let config::ValueKind::Boolean(value) = &value.kind {
+                            style.underlined = Some(*value);
+                        }
+                    }
                     result.insert(labels, style);
                 }
                 _ => {}
@@ -455,7 +470,8 @@ mod tests {
         colors.red_fg = { fg = "red" }
         colors.blue_bg = { bg = "blue" }
         colors.bold_font = { bold = true }
-        colors.multiple = { fg = "green", bg = "yellow", bold = true }
+        colors.underlined_text = { underlined = true }
+        colors.multiple = { fg = "green", bg = "yellow", bold = true, underlined = true }
         "#,
         );
         let mut output: Vec<u8> = vec![];
@@ -472,6 +488,10 @@ mod tests {
         formatter.write_str(" bold only ").unwrap();
         formatter.remove_label().unwrap();
         formatter.write_str("\n").unwrap();
+        formatter.add_label("underlined_text").unwrap();
+        formatter.write_str(" underlined only ").unwrap();
+        formatter.remove_label().unwrap();
+        formatter.write_str("\n").unwrap();
         formatter.add_label("multiple").unwrap();
         formatter.write_str(" single rule ").unwrap();
         formatter.remove_label().unwrap();
@@ -486,7 +506,8 @@ mod tests {
          fg only 
          bg only 
          bold only 
-         single rule 
+         underlined only 
+         single rule 
          two rules 
         "###);
     }
@@ -496,7 +517,7 @@ mod tests {
         // Test that we don't lose other attributes when we reset the bold attribute.
         let config = config_from_string(
             r#"
-        colors.not_bold = { fg = "red", bg = "blue" }
+        colors.not_bold = { fg = "red", bg = "blue", underlined = true }
         colors.bold_font = { bold = true }
         "#,
         );
@@ -509,7 +530,7 @@ mod tests {
         formatter.remove_label().unwrap();
         formatter.write_str(" not bold again ").unwrap();
         formatter.remove_label().unwrap();
-        insta::assert_snapshot!(String::from_utf8(output).unwrap(), @" not bold  bold  not bold again ");
+        insta::assert_snapshot!(String::from_utf8(output).unwrap(), @" not bold  bold  not bold again ");
     }
 
     #[test]