From 177881c6a3b8f43bebd3f391c91a66f5b7e2fa25 Mon Sep 17 00:00:00 2001
From: MsfPablo <pablogarciacaceres5@gmail.com>
Date: Thu, 13 Aug 2026 15:44:49 +0200
Subject: [PATCH] Honor NO_COLOR without suppressing text attributes

Per <https://no-color.org/>, the NO_COLOR convention is intended to
disable *color* output, not text attributes such as bold, italic, or
underline. The current behavior of the StyledObject fmt implementation
drops the attribute escapes whenever colors are disabled (which NO_COLOR
triggers), contradicting the spec.

Likewise, an empty value like `NO_COLOR=""` should not disable color,
but `env::var("NO_COLOR").is_ok()` returns true for any value,
including the empty string.

This commit:
* moves the attribute escape emission in impl_fmt! outside the
  colors_enabled() gate so attrs survive when colors are suppressed;
* changes `env::var("NO_COLOR").is_ok()` in the unix and windows
  backends to a non-empty check that matches the spec;
* adds a regression test exercising both behaviors.

Fixes #291
---
 src/unix_term.rs        |  2 +-
 src/utils.rs            | 53 +++++++++++++++++++++++++++++++++++++++++
 src/windows_term/mod.rs |  2 +-
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/src/unix_term.rs b/src/unix_term.rs
index 815d976a..154af2c7 100644
--- a/src/unix_term.rs
+++ b/src/unix_term.rs
@@ -27,7 +27,7 @@ pub(crate) fn is_a_color_terminal(out: &Term) -> bool {
         return false;
     }
 
-    if env::var("NO_COLOR").is_ok() {
+    if env::var_os("NO_COLOR").is_some_and(|v| !v.is_empty()) {
         return false;
     }
 
diff --git a/src/utils.rs b/src/utils.rs
index 3a48628e..e4537e4f 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -823,6 +823,16 @@ macro_rules! impl_fmt {
                         write!(f, "{}", self.style.attrs)?;
                         reset = true;
                     }
+                } else {
+                    // NO_COLOR and similar controls disable color, but per
+                    // <https://no-color.org/> text attributes (bold, italic,
+                    // underline, etc.) are not "color" and should remain
+                    // visible. Emit them outside the colors_enabled gate so
+                    // they survive when colors are suppressed.
+                    if !self.style.attrs.is_empty() {
+                        write!(f, "{}", self.style.attrs)?;
+                        reset = true;
+                    }
                 }
                 fmt::$name::fmt(&self.val, f)?;
                 if reset {
@@ -1227,3 +1237,46 @@ fn test_style_from_non_ascii_bg() {
     // silently ignores non-ascii
     assert_eq!(parsed_style, Style::default());
 }
+
+#[test]
+fn test_attrs_survive_colors_disabled() {
+    // Regression test for <https://github.com/console-rs/console/issues/291>:
+    // per <https://no-color.org/>, `NO_COLOR` suppresses *color*, not text
+    // attributes. When color output is otherwise disabled, attributes such as
+    // bold/italic/underline should still be emitted (with a trailing reset).
+    let prev = colors_enabled();
+    set_colors_enabled(false);
+
+    let bold = style("foo").bold().to_string();
+    assert!(
+        bold.contains("\x1b[1m"),
+        "bold escape sequence missing when colors are disabled: {bold:?}"
+    );
+    assert!(
+        bold.ends_with("\x1b[0m"),
+        "reset escape sequence missing after bold: {bold:?}"
+    );
+
+    let italic = style("bar").italic().to_string();
+    assert!(
+        italic.contains("\x1b[3m"),
+        "italic escape sequence missing when colors are disabled: {italic:?}"
+    );
+    assert!(
+        italic.ends_with("\x1b[0m"),
+        "reset escape sequence missing after italic: {italic:?}"
+    );
+
+    // Foreground color is *still* suppressed when colors are disabled.
+    let colored = style("baz").red().to_string();
+    assert!(
+        !colored.contains("\x1b[31m"),
+        "foreground color escape sequence should be suppressed when colors are disabled: {colored:?}"
+    );
+    assert!(
+        !colored.contains("\x1b[0m"),
+        "reset escape sequence should not be emitted when nothing is styled: {colored:?}"
+    );
+
+    set_colors_enabled(prev);
+}
diff --git a/src/windows_term/mod.rs b/src/windows_term/mod.rs
index 8d8a7803..a967c094 100644
--- a/src/windows_term/mod.rs
+++ b/src/windows_term/mod.rs
@@ -63,7 +63,7 @@ pub(crate) fn is_a_color_terminal(out: &Term) -> bool {
     if !is_a_terminal(out) {
         return false;
     }
-    if env::var("NO_COLOR").is_ok() {
+    if env::var_os("NO_COLOR").is_some_and(|v| !v.is_empty()) {
         return false;
     }
     if msys_tty_on(out) {