feat(output): allow forcing colored/coloured output (#218)

Fixes #182

Author: msabramo

radon/cli/colors.py

@@ -2,12 +2,23 @@
 terminal.
 '''
 
+import os
 import sys
 
+
+def color_enabled():
+    COLOR_ENV = os.getenv('COLOR', 'auto')
+    if COLOR_ENV == 'auto' and sys.stdout.isatty():
+        return True
+    if COLOR_ENV == 'yes':
+        return True
+    return False
+
+
 try:
     import colorama
 
-    colorama.init(strip=(not sys.stdout.isatty()))
+    colorama.init(strip=not color_enabled())
     GREEN, YELLOW, RED = (
         colorama.Fore.GREEN,
         colorama.Fore.YELLOW,

radon/tests/test_cli_colors.py

@@ -0,0 +1,22 @@
+import radon.cli.colors as colors
+
+
+def test_color_enabled_yes(monkeypatch):
+    monkeypatch.setenv("COLOR", "yes")
+    assert colors.color_enabled()
+
+
+def test_color_enabled_no(monkeypatch):
+    monkeypatch.setenv("COLOR", "no")
+    assert not colors.color_enabled()
+
+
+def test_color_enabled_auto(monkeypatch, mocker):
+    monkeypatch.setenv("COLOR", "auto")
+    isatty_mock = mocker.patch('sys.stdout.isatty')
+
+    isatty_mock.return_value = True
+    assert colors.color_enabled()
+
+    isatty_mock.return_value = False
+    assert not colors.color_enabled()