Add --stdout and --stderr args for base Command class

also refactor its `run()` method to allow more customizing ability

tests/commands/test_base.py

@@ -7,9 +7,10 @@ from unittest.mock import MagicMock, patch
 
 from wuttjamaican.commands import base
 from wuttjamaican.commands.setup import Setup
+from wuttjamaican.testing import FileConfigTestCase
 
 
-class TestCommand(TestCase):
+class TestCommand(FileConfigTestCase):
 
     def test_base(self):
         # base command is for 'wutta' and has a 'setup' subcommand
@@ -133,6 +134,37 @@ class TestCommand(TestCase):
         cmd.run('hello', '--foo')
         run_with.assert_called_once_with(foo=True)
 
+    def test_run_uses_stdout_stderr_params(self):
+        myout = self.write_file('my.out', '')
+        myerr = self.write_file('my.err', '')
+
+        class Hello(base.Subcommand):
+            name = 'hello'
+            def run(self, args):
+                self.stdout.write("hello world")
+                self.stderr.write("error text")
+
+        with patch('wuttjamaican.commands.base.sys') as sys:
+
+            cmd = base.Command(subcommands={'hello': Hello})
+
+            # sys.stdout and sys.stderr should be used by default
+            cmd.run('hello')
+            sys.exit.assert_not_called()
+            sys.stdout.write.assert_called_once_with('hello world')
+            sys.stderr.write.assert_called_once_with('error text')
+
+            # but our files may be used instead if specified
+            sys.reset_mock()
+            cmd.run('hello', '--stdout', myout, '--stderr', myerr)
+            sys.exit.assert_not_called()
+            sys.stdout.write.assert_not_called()
+            sys.stderr.write.assert_not_called()
+            with open(myout, 'rt') as f:
+                self.assertEqual(f.read(), 'hello world')
+            with open(myerr, 'rt') as f:
+                self.assertEqual(f.read(), 'error text')
+
 
 class TestCommandArgumentParser(TestCase):