First past at unit test for persistent history feature

Added pexpect to modules required for running unit tests.

This opens the door for carefully crafted complex unit tests to verify intricate behavior.  Tests like this are somewhat painful to write and slow to execute.  However, they can enable testing complicated interactive behavior that we otherwise probably would not be able to test.

Author: tleonhardt

Diff for: docs/requirements.txt

@@ -1,3 +1,4 @@
 pyparsing
 six
 pyperclip
+contextlib2

Diff for: examples/persistent_history.py

@@ -13,6 +13,7 @@ class Cmd2PersistentHistory(cmd2.Cmd):
     def __init__(self):
         """"""
         cmd2.Cmd.__init__(self, persistent_history_file='~/.persistent_history.cmd2', persistent_history_length=500)
+        self.prompt = 'ph> '
 
     # ... your class code here ...
 

Diff for: setup.py

@@ -77,7 +77,7 @@
     INSTALL_REQUIRES += ['subprocess32']
 
 # unittest.mock was added in Python 3.3.  mock is a backport of unittest.mock to all versions of Python
-TESTS_REQUIRE = ['mock', 'pytest']
+TESTS_REQUIRE = ['mock', 'pytest', 'pexpect']
 DOCS_REQUIRE = ['sphinx', 'sphinx_rtd_theme', 'pyparsing', 'pyperclip', 'six']
 
 setup(

Diff for: tests/test_cmd2.py

@@ -11,6 +11,7 @@
 import tempfile
 
 import mock
+import pexpect
 import pytest
 import six
 
@@ -1525,3 +1526,29 @@ def test_poutput_none(base_app):
     out = base_app.stdout.buffer
     expected = ''
     assert out == expected
+
+
+def test_persistent_history(request):
+    test_dir = os.path.dirname(request.module.__file__)
+    persistent_app = os.path.join(test_dir, '..', 'examples', 'persistent_history.py')
+
+    # STart an instance of the persistent history example and send it a few commands
+    child = pexpect.spawn(persistent_app)
+    prompt = 'ph> '
+    child.expect(prompt)
+    child.sendline('help')
+    child.expect(prompt)
+    child.sendline('help history')
+    child.expect(prompt)
+    child.sendline('quit')
+    child.close()
+
+    # Start a 2nd instance of the persistent history example and send it an up arrow to verify persistent history
+    up_arrow = '\x1b[A'
+    child2 = pexpect.spawn(persistent_app)
+    child2.expect(prompt)
+    child2.send(up_arrow)
+    child2.expect('quit', timeout=5)
+    assert child2.after == b'quit'
+
+

Diff for: tox.ini

@@ -13,6 +13,7 @@ setenv =
 deps =
   codecov
   mock
+  pexpect
   pyparsing
   pyperclip
   pytest
@@ -28,6 +29,7 @@ commands =
 deps =
   codecov
   mock
+  pexpect
   pyparsing
   pyperclip
   pyreadline
@@ -43,6 +45,7 @@ commands =
 [testenv:py34]
 deps =
   mock
+  pexpect
   pyparsing
   pyperclip
   pytest
@@ -53,6 +56,7 @@ commands = py.test -v -n2
 [testenv:py35]
 deps =
   mock
+  pexpect
   pyparsing
   pyperclip
   pytest
@@ -63,6 +67,7 @@ commands = py.test -v -n2
 [testenv:py35-win]
 deps =
   mock
+  pexpect
   pyparsing
   pyperclip
   pyreadline
@@ -75,6 +80,7 @@ commands = py.test -v -n2
 deps =
   codecov
   mock
+  pexpect
   pyparsing
   pyperclip
   pytest
@@ -88,6 +94,7 @@ commands =
 [testenv:py36-win]
 deps =
   mock
+  pexpect
   pyparsing
   pyperclip
   pyreadline
@@ -99,6 +106,7 @@ commands = py.test -v -n2
 [testenv:py37]
 deps =
   mock
+  pexpect
   pyparsing
   pyperclip
   pytest