Add --color setting to CLI.

src/config.rs

@@ -137,6 +137,12 @@ impl GlobalConfig {
         &mut self.stderr
     }
 
+    pub fn set_color_choice(mut self, choice: ColorChoice) -> Self {
+        self.stdout = StandardStream::stdout(choice);
+        self.stderr = StandardStream::stderr(choice);
+        self
+    }
+
     /// Print a message with a colored title in the style of Cargo shell messages.
     pub fn shell_print(
         &mut self,

src/lib.rs

@@ -35,6 +35,7 @@ pub struct Check {
     current: Rustdoc,
     baseline: Rustdoc,
     log_level: Option<log::Level>,
+    color_choice: Option<termcolor::ColorChoice>,
     release_type: Option<ReleaseType>,
     current_feature_config: rustdoc_gen::FeatureConfig,
     baseline_feature_config: rustdoc_gen::FeatureConfig,
@@ -247,6 +248,7 @@ impl Check {
             current,
             baseline: Rustdoc::from_registry_latest_crate_version(),
             log_level: Default::default(),
+            color_choice: None,
             release_type: None,
             current_feature_config: rustdoc_gen::FeatureConfig::default_for_current(),
             baseline_feature_config: rustdoc_gen::FeatureConfig::default_for_baseline(),
@@ -283,6 +285,21 @@ impl Check {
         self.log_level.as_ref()
     }
 
+    /// Set the termcolor [color choice](termcolor::ColorChoice)
+    /// If `None`, the use of colors will be determined automatically by
+    /// CARGO_TERM_COLOR env var and tty type of output`
+    pub fn with_color_choice(&mut self, choice: Option<termcolor::ColorChoice>) -> &mut Self {
+        self.color_choice = choice;
+        self
+    }
+
+    /// Get the current color choice.  If `None`, the use of colors is determined
+    /// by the `CARGO_TERM_COLOR` env var and whether the output is a tty
+    #[inline]
+    pub fn color_choice(&self) -> Option<&termcolor::ColorChoice> {
+        self.color_choice.as_ref()
+    }
+
     pub fn with_release_type(&mut self, release_type: ReleaseType) -> &mut Self {
         self.release_type = Some(release_type);
         self
@@ -386,6 +403,12 @@ impl Check {
 
     pub fn check_release(&self) -> anyhow::Result<Report> {
         let mut config = GlobalConfig::new().set_level(self.log_level);
+        // we don't want to set auto if the choice is not set because it would overwrite
+        // the value if the CARGO_TERM_COLOR env var read in GlobalConfig::new() if it is set
+        if let Some(choice) = self.color_choice {
+            config = config.set_color_choice(choice);
+        }
+
         let rustdoc_cmd = RustdocCommand::new().deps(false).silence(config.is_info());
 
         // If both the current and baseline rustdoc are given explicitly as a file path,

src/main.rs

@@ -25,6 +25,13 @@ fn main() {
         exit_on_error(true, || {
             let mut config =
                 GlobalConfig::new().set_level(args.check_release.verbosity.log_level());
+
+            // we don't want to set auto if the choice is not set because it would overwrite
+            // the value if the CARGO_TERM_COLOR env var read in GlobalConfig::new() if it is set
+            if let Some(choice) = args.check_release.color_choice {
+                config = config.set_color_choice(choice);
+            }
+
             let queries = SemverQuery::all_queries();
             let mut rows = vec![["id", "type", "description"], ["==", "====", "==========="]];
             for query in queries.values() {
@@ -282,6 +289,14 @@ struct CheckRelease {
 
     #[command(flatten)]
     verbosity: clap_verbosity_flag::Verbosity<clap_verbosity_flag::InfoLevel>,
+
+    #[arg(value_enum, long = "color")]
+    /// Whether to print colors to the terminal:
+    /// always, alwaysansi (always use only ANSI color codes),
+    /// auto (based on whether output is a tty), and never
+    ///
+    /// Default is auto (use colors if output is a TTY, otherwise don't use colors)
+    color_choice: Option<termcolor::ColorChoice>,
 }
 
 impl From<CheckRelease> for cargo_semver_checks::Check {
@@ -344,6 +359,7 @@ impl From<CheckRelease> for cargo_semver_checks::Check {
         }
 
         check.with_log_level(value.verbosity.log_level());
+        check.with_color_choice(value.color_choice);
 
         if let Some(release_type) = value.release_type {
             check.with_release_type(release_type);