cli: add formatter config

This class will be used across the codebase serving as global
configuration for colors, utf-8 support and suggestions on the CLI.

Signed-off-by: Renan Rodrigo <[email protected]>

uaclient/cli/formatter.py

@@ -0,0 +1,38 @@
+import os
+import sys
+
+from uaclient.config import UAConfig
+
+
+# Class attributes and methods so we don't need singletons or globals for this
+class ProOutputFormatterConfig:
+    use_utf8 = True
+    use_color = True
+    show_suggestions = True
+
+    # Initializing the class after the import is useful for unit testing
+    @classmethod
+    def init(cls, cfg: UAConfig):
+        cls.use_utf8 = (
+            sys.stdout.encoding is not None
+            and "UTF-8" in sys.stdout.encoding.upper()
+        )
+
+        cls.use_color = (
+            sys.stdout.isatty()
+            and os.getenv("NO_COLOR") is None
+            and cfg.cli_color
+        )
+
+        cls.show_suggestions = cfg.cli_suggestions
+
+    @classmethod
+    def disable_color(cls) -> None:
+        cls.use_color = False
+
+    @classmethod
+    def disable_suggestions(cls) -> None:
+        cls.show_suggestions = False
+
+
+ProOutputFormatterConfig.init(cfg=UAConfig())

uaclient/cli/tests/test_cli_formatter.py

@@ -0,0 +1,65 @@
+import mock
+import pytest
+
+from uaclient.cli.formatter import ProOutputFormatterConfig as POFC
+
+M_PATH = "uaclient.cli.formatter."
+
+
+class TestProFormatterConfig:
+    @pytest.mark.parametrize(
+        "system_encoding,expected_use_utf8",
+        ((None, False), ("iso-8859-13", False), ("utf-8", True)),
+    )
+    def test_use_utf8(self, system_encoding, expected_use_utf8, FakeConfig):
+        cfg = FakeConfig()
+
+        with mock.patch(M_PATH + "sys.stdout") as m_stdout:
+            m_stdout.encoding = system_encoding
+            POFC.init(cfg)
+
+        assert POFC.use_utf8 is expected_use_utf8
+
+    @pytest.mark.parametrize("config_value", (True, False))
+    @pytest.mark.parametrize("is_tty", (True, False))
+    @pytest.mark.parametrize("env_no_color", ("True", None))
+    @mock.patch(M_PATH + "sys.stdout.isatty")
+    @mock.patch(M_PATH + "os.getenv")
+    def test_color_config(
+        self,
+        m_getenv,
+        m_is_tty,
+        config_value,
+        is_tty,
+        env_no_color,
+        FakeConfig,
+    ):
+        cfg = FakeConfig()
+        cfg.user_config.cli_color = config_value
+
+        m_is_tty.return_value = is_tty
+
+        m_getenv.return_value = env_no_color
+
+        POFC.init(cfg)
+
+        expected_result = True
+        if any((config_value is False, not is_tty, env_no_color)):
+            expected_result = False
+
+        assert POFC.use_color is expected_result
+
+        POFC.disable_color()
+        assert POFC.use_color is False
+
+    @pytest.mark.parametrize("config_value", (True, False))
+    def test_suggestions_config(self, config_value, FakeConfig):
+        cfg = FakeConfig()
+        cfg.user_config.cli_suggestions = config_value
+
+        POFC.init(cfg)
+
+        assert POFC.show_suggestions is config_value
+
+        POFC.disable_suggestions()
+        assert POFC.show_suggestions is False