Cover "list", "search" and "settings" commands with tests

tests/commands/test_settings.py

@@ -0,0 +1,24 @@
+# Copyright (C) Ivan Kravets <me@ikravets.com>
+# See LICENSE for details.
+
+
+from click.testing import CliRunner
+
+from platformio.commands.settings import cli
+from platformio import app
+
+runner = CliRunner()
+
+
+def validate_output(result):
+    assert result.exit_code == 0
+    assert not result.exception
+    assert "error" not in result.output.lower()
+
+
+def test_settings_check():
+    result = runner.invoke(cli, ["get"])
+    validate_output(result)
+    assert len(result.output)
+    for item in app.DEFAULT_SETTINGS.items():
+        assert item[0] in result.output