feat: add option to only highlight the gutter for coverage info

assets/index.css

@@ -130,6 +130,14 @@
     @apply bg-red-400 hover:bg-red-500 dark:bg-red-800 dark:hover:bg-red-700;
   }
 
+  .gutter.covered {
+    @apply bg-green-400 dark:bg-green-800 !important;
+  }
+
+  .gutter.uncovered {
+    @apply bg-red-400 dark:bg-red-800 !important;
+  }
+
   .page-footer {
     @apply text-sm font-bold pl-4 pt-4;
   }

src/cli.rs

@@ -1,12 +1,13 @@
 //! Handling of command line arguments.
 
 use std::{
+    fmt::{self, Display},
     fs::OpenOptions,
     io::{self, BufWriter, Write},
 };
 
 use camino::{Utf8Path, Utf8PathBuf};
-use clap::{CommandFactory, Parser, Subcommand, ValueHint};
+use clap::{CommandFactory, Parser, Subcommand, ValueEnum, ValueHint};
 use clap_complete::Shell;
 use color_eyre::eyre::{ensure, Result, WrapErr};
 
@@ -24,6 +25,9 @@ pub struct Cli {
     /// The highlighting theme to use, if not disabled.
     #[arg(long, default_value_t = Theme::OneHalf)]
     pub theme: Theme,
+    /// Where to place the coverage color marker.
+    #[arg(long, default_value_t = CoverageStyle::Line)]
+    pub coverage_style: CoverageStyle,
     /// Location of the project's Cargo.toml, in case the default detection isn't sufficient.
     #[arg(long)]
     pub manifest_path: Option<Utf8PathBuf>,
@@ -40,6 +44,24 @@ impl Cli {
     }
 }
 
+/// The way in which to mark source code lines as covered or uncovered.
+#[derive(Clone, Copy, Eq, PartialEq, ValueEnum)]
+pub enum CoverageStyle {
+    /// Highlight the whole source line.
+    Line,
+    /// Only highlight the gutter (count column).
+    Gutter,
+}
+
+impl Display for CoverageStyle {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(match self {
+            Self::Line => "line",
+            Self::Gutter => "gutter",
+        })
+    }
+}
+
 #[derive(Subcommand)]
 pub enum Command {
     /// Generate auto-completions scripts for various shells.

src/main.rs

@@ -115,6 +115,7 @@ fn main() -> Result<()> {
                     base_dir: &"../".repeat(file.relative_path.ancestors().skip(2).count()),
                     lines: &lines,
                     info: &file,
+                    coverage_style: cli.coverage_style,
                     show_instantiations: cli.show_instantiations,
                 }
                 .render()?

src/templates.rs

@@ -6,7 +6,7 @@ use askama::Template;
 use camino::Utf8PathBuf;
 use time::OffsetDateTime;
 
-use crate::schema;
+use crate::{cli::CoverageStyle, schema};
 
 /// Global constant instance with this project's info, so it doesn't have to be included as part of
 /// each template struct.
@@ -62,6 +62,7 @@ pub struct Source<'a> {
     pub base_dir: &'a str,
     pub lines: &'a [String],
     pub info: &'a FileInfo,
+    pub coverage_style: CoverageStyle,
     pub show_instantiations: bool,
 }
 
@@ -148,8 +149,7 @@ mod tests {
     use camino::Utf8PathBuf;
     use time::OffsetDateTime;
 
-    use super::FileInfo;
-    use crate::schema;
+    use super::{schema, CoverageStyle, FileInfo};
 
     #[test]
     fn render_index() {
@@ -187,6 +187,7 @@ mod tests {
                 called: HashMap::default(),
                 uncalled: HashMap::default(),
             },
+            coverage_style: CoverageStyle::Line,
             show_instantiations: true,
         }
         .render()

templates/source.html

@@ -45,25 +45,26 @@
         <td>
           <a name="L{{loop.index}}" href="#L{{loop.index}}">{{loop.index}}</a>
         </td>
-        <td>
-          {% match self.get_coverage(loop.index) %}
-            {% when Coverage::Covered(count) %}
-              {{count}}
-            {% when Coverage::Uncovered(count) %}
-              {{count}}
-            {% when Coverage::Unknown %}
-          {% endmatch %}
-        </td>
+        {% let coverage = self.get_coverage(loop.index) %}
         {% let class %}
-        {% match self.get_coverage(loop.index) %}
+        {% match coverage %}
           {% when Coverage::Covered(_) %}
             {% let class = "covered" %}
           {% when Coverage::Uncovered(_) %}
             {% let class = "uncovered" %}
           {% when Coverage::Unknown %}
             {% let class = "" %}
         {% endmatch %}
-        <td class="{{class}}">
+        <td{% if coverage_style == CoverageStyle::Gutter %} class="gutter {{class}}"{% endif %}>
+          {% match coverage %}
+            {% when Coverage::Covered(count) %}
+              {{count}}
+            {% when Coverage::Uncovered(count) %}
+              {{count}}
+            {% when Coverage::Unknown %}
+          {% endmatch %}
+        </td>
+        <td{% if coverage_style == CoverageStyle::Line %} class="{{class}}"{% endif %}>
           <pre>{{line|safe}}</pre>
           {% if show_instantiations %}
             {% if let Some(functions) = self.info.uncalled.get(loop.index) %}