Don't use Ansi Colors if not supported.

detect_secrets/util/color.py

@@ -1,4 +1,11 @@
 from enum import Enum
+from os import getenv
+from sys import stdout
+
+
+def supports_ansi_colors() -> bool:
+    return (getenv('CLICOLOR', '1') != '0' and stdout.isatty())\
+        or getenv('CLICOLOR_FORCE', '0') != '0'
 
 
 class AnsiColor(Enum):
@@ -11,6 +18,9 @@ class AnsiColor(Enum):
 
 
 def colorize(text: str, color: AnsiColor) -> str:
+    if not supports_ansi_colors():
+        return text
+
     return '\x1b{}{}\x1b{}'.format(
         color.value,
         text,

tests/util/color_test.py

@@ -0,0 +1,44 @@
+from sys import stdout
+
+from detect_secrets.util.color import AnsiColor
+from detect_secrets.util.color import colorize
+
+
+def colorize_enabled(text: str, color: AnsiColor) -> str:
+    return '\x1b{}{}\x1b{}'.format(
+        color.value,
+        text,
+        AnsiColor.RESET.value,
+    )
+
+
+def expect_enabled(text: str):
+    for color in AnsiColor:
+        expected = colorize_enabled(text, color)
+        assert colorize(text, color) == expected
+
+
+def expect_disabled(text: str):
+    for color in AnsiColor:
+        assert colorize(text, color) == text
+
+
+def test_colorize_enabled_terminal_disabled_piped(monkeypatch):
+    monkeypatch.setenv('CLICOLOR', '1')
+
+    if stdout.isatty():
+        expect_enabled('abc')
+    else:
+        expect_disabled('abc')
+
+
+def test_colorize_enabled_force(monkeypatch):
+    monkeypatch.setenv('CLICOLOR_FORCE', '1')
+
+    expect_enabled('abc')
+
+
+def test_colorize_disabled(monkeypatch):
+    monkeypatch.setenv('CLICOLOR', '0')
+
+    expect_disabled('abc')