Add color to error and mismatch messages (#42)

Author: casey

Cargo.lock

@@ -19,6 +19,7 @@ clap = { version = "4.5.16", features = ["derive"] }
 clap_mangen = "0.2.23"
 indicatif = "0.17.8"
 lexiclean = "0.0.1"
+owo-colors = "4"
 serde = { version = "1.0.209", features = ["derive"] }
 serde_json = "1.0.127"
 snafu = "0.8.4"

Cargo.toml

@@ -75,7 +75,7 @@ pub(crate) enum Error {
     backtrace: Option<Backtrace>,
     path: DisplayPath,
   },
-  #[snafu(context(false))]
+  #[snafu(transparent)]
   WalkDir {
     backtrace: Option<Backtrace>,
     source: walkdir::Error,

src/error.rs

@@ -2,13 +2,15 @@ use {
   self::{
     arguments::Arguments, display_path::DisplayPath, entry::Entry, error::Error, hash::Hash,
     lint::Lint, lint_group::LintGroup, list::List, manifest::Manifest, options::Options,
-    relative_path::RelativePath, subcommand::Subcommand,
+    owo_colorize_ext::OwoColorizeExt, relative_path::RelativePath, style::Style,
+    subcommand::Subcommand,
   },
   blake3::Hasher,
   camino::{Utf8Component, Utf8Path, Utf8PathBuf},
   clap::{Parser, ValueEnum},
   indicatif::{ProgressBar, ProgressStyle},
   lexiclean::Lexiclean,
+  owo_colors::Styled,
   serde::{Deserialize, Deserializer, Serialize, Serializer},
   snafu::{ensure, ErrorCompat, OptionExt, ResultExt, Snafu},
   std::{
@@ -17,7 +19,7 @@ use {
     env,
     fmt::{self, Display, Formatter},
     fs::{self, File},
-    io,
+    io::{self, IsTerminal},
     path::{Path, PathBuf},
     process,
     str::{self, FromStr},
@@ -35,15 +37,22 @@ mod lint_group;
 mod list;
 mod manifest;
 mod options;
+mod owo_colorize_ext;
 mod progress_bar;
 mod relative_path;
+mod style;
 mod subcommand;
 
 type Result<T = (), E = Error> = std::result::Result<T, E>;
 
 fn main() {
   if let Err(err) = Arguments::parse().run() {
-    eprintln!("error: {err}");
+    let style = Style::stderr();
+    eprintln!(
+      "{}: {}",
+      "error".style(style.error()),
+      err.style(style.message()),
+    );
 
     let causes = err.iter_chain().skip(1).count();
 

src/main.rs

@@ -0,0 +1,11 @@
+use super::*;
+
+pub(crate) trait OwoColorizeExt {
+  fn style(&self, style: Style) -> Styled<&Self>;
+}
+
+impl<T: owo_colors::OwoColorize> OwoColorizeExt for T {
+  fn style(&self, style: Style) -> Styled<&Self> {
+    self.style(style.effective_style())
+  }
+}

src/owo_colorize_ext.rs

@@ -0,0 +1,52 @@
+use super::*;
+
+#[derive(Clone, Copy)]
+pub(crate) struct Style {
+  is_terminal: bool,
+  inner: owo_colors::Style,
+}
+
+impl Style {
+  pub(crate) fn bad(self) -> Self {
+    Self {
+      inner: self.inner.red(),
+      ..self
+    }
+  }
+
+  pub(crate) fn error(self) -> Self {
+    Self {
+      inner: self.inner.red(),
+      ..self
+    }
+  }
+
+  pub(crate) fn good(self) -> Self {
+    Self {
+      inner: self.inner.green(),
+      ..self
+    }
+  }
+
+  pub(crate) fn effective_style(self) -> owo_colors::Style {
+    if self.is_terminal {
+      self.inner
+    } else {
+      owo_colors::Style::default()
+    }
+  }
+
+  pub(crate) fn message(self) -> Self {
+    Self {
+      inner: self.inner.bold(),
+      ..self
+    }
+  }
+
+  pub(crate) fn stderr() -> Self {
+    Self {
+      is_terminal: io::stderr().is_terminal(),
+      inner: owo_colors::Style::default(),
+    }
+  }
+}

src/style.rs

@@ -70,12 +70,29 @@ impl Verify {
 
     if !mismatches.is_empty() {
       for (path, (actual, expected)) in &mismatches {
+        let style = Style::stderr();
+
+        let hash_style = if expected.hash == actual.hash {
+          style.good()
+        } else {
+          style.bad()
+        };
+
+        let size_style = if expected.size == actual.size {
+          style.good()
+        } else {
+          style.bad()
+        };
+
         eprintln!(
           "\
 mismatched file: `{path}`
        manifest: {} ({} bytes)
            file: {} ({} bytes)",
-          expected.hash, expected.size, actual.hash, actual.size,
+          expected.hash.style(style.good()),
+          expected.size.style(style.good()),
+          actual.hash.style(hash_style),
+          actual.size.style(size_style),
         );
       }