Add simple, stdin based confirmator

src/confirmator.py

@@ -0,0 +1,9 @@
+import sys
+
+
+class Confirmator(object):
+
+    def confirm(self, text):
+        sys.stdout.write(text)
+        answer = sys.stdin.readline().strip()
+        return answer == 'y' or answer == 'Y' or answer == ''

tests/confirmator_test.py

@@ -0,0 +1,67 @@
+import sys
+
+from confirmator import Confirmator
+from test_helper import assert_printed, assert_not_printed, Test
+
+
+class FakeStdin(object):
+
+    def set_line(self, line):
+        self.line = line
+
+    def readline(self):
+        return self.line
+
+
+class TestConfirmator(Test):
+
+    def setUp(self):
+        Test.setUp(self)
+        self.real_stdin = sys.stdin
+        sys.stdin = self.stdin = FakeStdin()
+
+    def tearDown(self):
+        Test.tearDown(self)
+        sys.stdin = self.real_stdin
+
+    def test_confirm_when_y_entered(self):
+        confirmator = Confirmator()
+        self.stdin.set_line("y\n")
+
+        assert confirmator.confirm('Wanna?')
+        assert_printed('Wanna?')
+
+    def test_confirm_when_Y_entered(self):
+        confirmator = Confirmator()
+        self.stdin.set_line("Y\n")
+
+        assert confirmator.confirm('Wanna?')
+        assert_printed('Wanna?')
+
+    def test_confirm_when_enter_hit(self):
+        confirmator = Confirmator()
+        self.stdin.set_line("\n")
+
+        assert confirmator.confirm('Wanna?')
+        assert_printed('Wanna?')
+
+    def test_confirm_when_spaces_entered(self):
+        confirmator = Confirmator()
+        self.stdin.set_line("  \n")
+
+        assert confirmator.confirm('Wanna?')
+        assert_printed('Wanna?')
+
+    def test_confirm_when_n_entered(self):
+        confirmator = Confirmator()
+        self.stdin.set_line("n\n")
+
+        assert not confirmator.confirm('Wanna?')
+        assert_printed('Wanna?')
+
+    def test_confirm_when_foo_entered(self):
+        confirmator = Confirmator()
+        self.stdin.set_line("foo\n")
+
+        assert not confirmator.confirm('Wanna?')
+        assert_printed('Wanna?')