refactor: Use is-terminal instead of atty

This follows suit with clap, which also changed to is-terminal, to
eliminate a redundant dependency and perhaps have a better maintained
library.

Refs: clap-rs/clap#4249

Cargo.toml

@@ -18,7 +18,6 @@ name = "stg"
 
 [dependencies]
 anyhow = "1.0"
-atty = "0.2"
 bstr = { version = "1.0", default-features = false, features = ["std"] }
 chrono = { version = "0.4", default-features = false, features = ["clock"] }
 clap = { version = "4.0", default-features = false, features = [
@@ -34,6 +33,7 @@ ctrlc = "3.2"
 encoding_rs = "0.8"
 git2 = { version = "0.15", default-features = false }
 indexmap = "1.8"
+is-terminal = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 strsim = "0.10"

src/color.rs

@@ -5,6 +5,7 @@
 use std::ffi::OsString;
 
 use clap::{Arg, ArgMatches};
+use is_terminal::IsTerminal;
 use termcolor::StandardStream;
 
 pub(crate) fn get_color_arg() -> Arg {
@@ -56,7 +57,7 @@ pub(crate) fn termcolor_choice_to_clap(color_choice: termcolor::ColorChoice) ->
 /// Get [`termcolor::StandardStream`] for stdout based on `--color` option.
 pub(crate) fn get_color_stdout(matches: &ArgMatches) -> StandardStream {
     let mut choice = get_color_choice(Some(matches));
-    if choice == termcolor::ColorChoice::Auto && atty::isnt(atty::Stream::Stdout) {
+    if choice == termcolor::ColorChoice::Auto && !std::io::stdout().is_terminal() {
         choice = termcolor::ColorChoice::Never;
     }
     StandardStream::stdout(choice)
@@ -65,7 +66,7 @@ pub(crate) fn get_color_stdout(matches: &ArgMatches) -> StandardStream {
 /// Get [`termcolor::StandardStream`] for stderr based on `--color` option.
 pub(crate) fn get_color_stderr(matches: &ArgMatches) -> StandardStream {
     let mut choice = get_color_choice(Some(matches));
-    if choice == termcolor::ColorChoice::Auto && atty::isnt(atty::Stream::Stderr) {
+    if choice == termcolor::ColorChoice::Auto && !std::io::stderr().is_terminal() {
         choice = termcolor::ColorChoice::Never;
     }
     StandardStream::stderr(choice)
@@ -85,7 +86,7 @@ pub(crate) fn get_color_choice(maybe_matches: Option<&ArgMatches>) -> termcolor:
 pub(crate) fn use_color(matches: &ArgMatches) -> bool {
     match crate::color::get_color_choice(Some(matches)) {
         termcolor::ColorChoice::Always | termcolor::ColorChoice::AlwaysAnsi => true,
-        termcolor::ColorChoice::Auto => atty::is(atty::Stream::Stdout),
+        termcolor::ColorChoice::Auto => std::io::stdout().is_terminal(),
         termcolor::ColorChoice::Never => false,
     }
 }

src/main.rs

@@ -572,8 +572,9 @@ pub(crate) fn print_warning_message(matches: &ArgMatches, msg: &str) {
 
 /// Print user-facing error message to stderr.
 fn print_error_message(color_choice: Option<termcolor::ColorChoice>, err: &anyhow::Error) {
+    use is_terminal::IsTerminal;
     let color_choice = color_choice.unwrap_or_else(|| {
-        if atty::is(atty::Stream::Stderr) {
+        if std::io::stderr().is_terminal() {
             termcolor::ColorChoice::Auto
         } else {
             termcolor::ColorChoice::Never