feat(stream_output): respect FORCE_COLOR (#343)

news/343.feat.md

@@ -0,0 +1 @@
+ANSI coloring detection now respects a `FORCE_COLOR` environment variable.

src/cleo/io/outputs/stream_output.py

@@ -87,6 +87,8 @@ def _has_color_support(self) -> bool:
         # Follow https://no-color.org/
         if "NO_COLOR" in os.environ:
             return False
+        if "FORCE_COLOR" in os.environ:
+            return True
 
         if os.getenv("TERM_PROGRAM") == "Hyper":
             return True

tests/io/outputs/test_stream_output.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+import os
+
+from io import StringIO
+
+import pytest
+
+from cleo.io.outputs.stream_output import StreamOutput
+
+
+@pytest.fixture()
+def stream() -> StringIO:
+    return StringIO()
+
+
+@pytest.mark.parametrize(
+    ["env", "is_decorated"],
+    [
+        ({"NO_COLOR": "1"}, False),
+        ({"FORCE_COLOR": "1"}, True),
+    ],
+)
+def test_is_decorated_respects_environment(
+    stream: StringIO, environ: None, env: dict[str, str], is_decorated: bool
+) -> None:
+    os.environ.update(env)
+
+    output = StreamOutput(stream)
+    output.write_line("<fg=blue>FooBar</>")
+    stream.seek(0)
+
+    assert output.is_decorated() == is_decorated
+    expected = "\x1b[34mFooBar\x1b[39m\n" if is_decorated else "FooBar\n"
+    assert stream.read() == expected