From bc04e1ac0062c0593f05c6ea9445e7419242c751 Mon Sep 17 00:00:00 2001
From: Lovecraftian Horror <LovecraftianHorror@pm.me>
Date: Thu, 9 Apr 2020 15:14:16 -0400
Subject: [PATCH] Disable styling for `--color auto` if the output is being
 piped

---
 Cargo.lock   |  1 +
 Cargo.toml   |  1 +
 src/main.rs  | 11 ++++++++---
 tests/lib.rs |  4 ++--
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index c23d2d35e..feeec7df1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1178,6 +1178,7 @@ dependencies = [
  "ansi_term 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "app_dirs2 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "assert_cmd 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "docopt 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "escargot 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/Cargo.toml b/Cargo.toml
index f82ae84e1..7246dbab1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,6 +17,7 @@ path = "src/main.rs"
 [dependencies]
 ansi_term = "0.12.0"
 app_dirs = { version = "2", package = "app_dirs2" }
+atty = "0.2"
 docopt = "1"
 env_logger = { version = "0.7", optional = true }
 flate2 = "1"
diff --git a/src/main.rs b/src/main.rs
index f1673e9a9..98e14076b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -25,6 +25,7 @@ use std::process;
 
 use ansi_term::{Color, Style};
 use app_dirs::AppInfo;
+use atty::Stream;
 use docopt::Docopt;
 #[cfg(not(target_os = "windows"))]
 use pager::Pager;
@@ -323,9 +324,13 @@ fn main() {
     let enable_styles = match args.flag_color {
         // Always use styling as long as there is `ansi_support`
         ColorOptions::Always => ansi_support,
-        // Disable if:
-        // * NO_COLOR env var is set to anything: https://no-color.org/
-        ColorOptions::Auto => ansi_support && env::var_os("NO_COLOR").is_none(),
+        // Enable styling if:
+        // * There is `ansi_support`
+        // * NO_COLOR env var isn't set: https://no-color.org/
+        // * The output stream is stdout (not being piped)
+        ColorOptions::Auto => {
+            ansi_support && env::var_os("NO_COLOR").is_none() && atty::is(Stream::Stdout)
+        }
         // Disable styling
         ColorOptions::Never => false,
     };
diff --git a/tests/lib.rs b/tests/lib.rs
index 856d537b0..b2b2aa541 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -253,7 +253,7 @@ fn _test_correct_rendering(input_file: &str, filename: &str) {
     let expected = include_str!("inkscape-default.expected");
     testenv
         .command()
-        .args(&["-f", &file_path.to_str().unwrap()])
+        .args(&["--color", "always", "-f", &file_path.to_str().unwrap()])
         .assert()
         .success()
         .stdout(similar(expected));
@@ -299,7 +299,7 @@ fn test_correct_rendering_with_config() {
 
     testenv
         .command()
-        .args(&["-f", &file_path.to_str().unwrap()])
+        .args(&["--color", "always", "-f", &file_path.to_str().unwrap()])
         .assert()
         .success()
         .stdout(similar(expected));