Auto merge of rust-lang#12751 - epage:color, r=arlosi

refactor: Switch from termcolor to anstream

### What does this PR try to resolve?

`anstream` asks the question "what if you took `fwdansi` and removed `termcolor` underneath it.  It wraps output streams, adapting ANSI escape codes to what is needed
- Pass through if its supported
- Strip if its not
- Adapt to wincon API if needed

Benefits
- Lower boilerplate: we can use `write!` with styled text rather than the back-and-forth between colors and writing that termcolor needs
- Allows richer styling as `Shell` can accept styled messages and adapt them as needed

Side effects
- We'll now respect [NO_COLOR](https://no-color.org/), [CLICOLOR_FORCE](https://bixense.com/clicolors/), and [CLICOLOR](jhasse/clicolors@3a22aaa)

Fixes rust-lang#12627

### How should we test and review this PR?

This is broken up by commits for easier browsing.

However, as there aren't really tests for colored output, this needs hand inspection to verify

### Additional information

This allowed us to remove the need for stripping ansi escape codes completely.  Even if it didn't, it exposes its internal stripping API for reuse, saving on a dependency and being significantly faster.

Cargo.toml

@@ -16,8 +16,8 @@ edition = "2021"
 license = "MIT OR Apache-2.0"
 
 [workspace.dependencies]
-anstyle = "1.0.3"
-anstyle-termcolor = "1.1.0"
+anstream = "0.6.3"
+anstyle = "1.0.4"
 anyhow = "1.0.75"
 base64 = "0.21.3"
 bytesize = "1.3"
@@ -31,7 +31,7 @@ cargo-test-macro = { path = "crates/cargo-test-macro" }
 cargo-test-support = { path = "crates/cargo-test-support" }
 cargo-util = { version = "0.2.6", path = "crates/cargo-util" }
 cargo_metadata = "0.17.0"
-clap = "4.4.4"
+clap = "4.4.6"
 color-print = "0.3.4"
 core-foundation = { version = "0.9.3", features = ["mac_os_10_7_support"] }
 crates-io = { version = "0.39.0", path = "crates/crates-io" }
@@ -40,7 +40,6 @@ curl = "0.4.44"
 curl-sys = "0.4.66"
 filetime = "0.2.22"
 flate2 = { version = "1.0.27", default-features = false, features = ["zlib"] }
-fwdansi = "1.1.0"
 git2 = "0.18.0"
 git2-curl = "0.19.0"
 gix = { version = "0.54.1", default-features = false, features = ["blocking-http-transport-curl", "progress-tree", "revision"] }
@@ -86,12 +85,10 @@ serde_json = "1.0.105"
 sha1 = "0.10.5"
 sha2 = "0.10.7"
 shell-escape = "0.1.5"
-snapbox = { version = "0.4.12", features = ["diff", "path"] }
-strip-ansi-escapes = "0.1.1"
+snapbox = { version = "0.4.13", features = ["diff", "path"] }
 syn = { version = "2.0.29", features = ["extra-traits", "full"] }
 tar = { version = "0.4.40", default-features = false }
 tempfile = "3.8.0"
-termcolor = "1.2.0"
 thiserror = "1.0.47"
 time = { version = "0.3", features = ["parsing", "formatting", "serde"] }
 toml = "0.7.6"
@@ -123,8 +120,8 @@ name = "cargo"
 path = "src/cargo/lib.rs"
 
 [dependencies]
+anstream.workspace = true
 anstyle.workspace = true
-anstyle-termcolor.workspace = true
 anyhow.workspace = true
 base64.workspace = true
 bytesize.workspace = true
@@ -175,11 +172,9 @@ serde_ignored.workspace = true
 serde_json = { workspace = true, features = ["raw_value"] }
 sha1.workspace = true
 shell-escape.workspace = true
-strip-ansi-escapes.workspace = true
 syn.workspace = true
 tar.workspace = true
 tempfile.workspace = true
-termcolor.workspace = true
 time.workspace = true
 toml.workspace = true
 toml_edit.workspace = true
@@ -194,9 +189,6 @@ walkdir.workspace = true
 [target.'cfg(not(windows))'.dependencies]
 openssl = { workspace = true, optional = true }
 
-[target.'cfg(windows)'.dependencies]
-fwdansi.workspace = true
-
 [target.'cfg(windows)'.dependencies.windows-sys]
 workspace = true
 features = [

crates/cargo-test-support/Cargo.toml

@@ -10,6 +10,8 @@ publish = false
 doctest = false
 
 [dependencies]
+anstream.workspace = true
+anstyle.workspace = true
 anyhow.workspace = true
 cargo-test-macro.workspace = true
 cargo-util.workspace = true
@@ -24,7 +26,6 @@ serde = { workspace = true, features = ["derive"] }
 serde_json.workspace = true
 snapbox.workspace = true
 tar.workspace = true
-termcolor.workspace = true
 time.workspace = true
 toml.workspace = true
 url.workspace = true

crates/cargo-test-support/src/diff.rs

@@ -7,7 +7,6 @@
 
 use std::fmt;
 use std::io::Write;
-use termcolor::{Ansi, Color, ColorSpec, NoColor, WriteColor};
 
 /// A single line change to be applied to the original.
 #[derive(Debug, Eq, PartialEq)]
@@ -111,42 +110,35 @@ where
 }
 
 pub fn render_colored_changes<T: fmt::Display>(changes: &[Change<T>]) -> String {
-    // termcolor is not very ergonomic, but I don't want to bring in another dependency.
-    let mut red = ColorSpec::new();
-    red.set_fg(Some(Color::Red));
-    let mut green = ColorSpec::new();
-    green.set_fg(Some(Color::Green));
-    let mut dim = ColorSpec::new();
-    dim.set_dimmed(true);
-    let mut v = Vec::new();
-    let mut result: Box<dyn WriteColor> = if crate::is_ci() {
+    // anstyle is not very ergonomic, but I don't want to bring in another dependency.
+    let red = anstyle::AnsiColor::Red.on_default().render();
+    let green = anstyle::AnsiColor::Green.on_default().render();
+    let dim = (anstyle::Style::new() | anstyle::Effects::DIMMED).render();
+    let bold = (anstyle::Style::new() | anstyle::Effects::BOLD).render();
+    let reset = anstyle::Reset.render();
+
+    let choice = if crate::is_ci() {
         // Don't use color on CI. Even though GitHub can display colors, it
         // makes reading the raw logs more difficult.
-        Box::new(NoColor::new(&mut v))
+        anstream::ColorChoice::Never
     } else {
-        Box::new(Ansi::new(&mut v))
+        anstream::AutoStream::choice(&std::io::stdout())
     };
+    let mut buffer = anstream::AutoStream::new(Vec::new(), choice);
 
     for change in changes {
         let (nums, sign, color, text) = match change {
-            Change::Add(i, s) => (format!("    {:<4} ", i), '+', &green, s),
-            Change::Remove(i, s) => (format!("{:<4}     ", i), '-', &red, s),
-            Change::Keep(x, y, s) => (format!("{:<4}{:<4} ", x, y), ' ', &dim, s),
+            Change::Add(i, s) => (format!("    {:<4} ", i), '+', green, s),
+            Change::Remove(i, s) => (format!("{:<4}     ", i), '-', red, s),
+            Change::Keep(x, y, s) => (format!("{:<4}{:<4} ", x, y), ' ', dim, s),
         };
-        result.set_color(&dim).unwrap();
-        write!(result, "{}", nums).unwrap();
-        let mut bold = color.clone();
-        bold.set_bold(true);
-        result.set_color(&bold).unwrap();
-        write!(result, "{}", sign).unwrap();
-        result.reset().unwrap();
-        result.set_color(&color).unwrap();
-        write!(result, "{}", text).unwrap();
-        result.reset().unwrap();
-        writeln!(result).unwrap();
+        write!(
+            buffer,
+            "{dim}{nums}{reset}{bold}{sign}{reset}{color}{text}{reset}"
+        )
+        .unwrap();
     }
-    drop(result);
-    String::from_utf8(v).unwrap()
+    String::from_utf8(buffer.into_inner()).unwrap()
 }
 
 #[cfg(test)]