Correct completion in interactive mode

Currently, in interactive mode, cliff shows cmd/cmd2 style
commands[1] matching written prefix in completion list but not cliff
style commands[2]:

* for command prefix without completer delimiter, InteractiveAPP uses
  cmd completion method (completenames) and returns only cmd/cmd2 style
  command candidates,
* for command prefix with completer delimiter, InteractiveAPP uses its
  completion method (completedefault) but with an incorrect filter and
  returns no or incorrect candidates.

This change defines completenames method to add cliff style commands in
completion and corrects completedefault method implementation.

[1]: commands defined through a do_$method in $method InteractiveApp
     class or subclasses. By consequence, $method contains no completer
     delimiter.
[2]: commands defined using cliff command-manager

Change-Id: I84a64212acb305e5bfcf25282ad21a694a6826a9
Closes-Bug: #1424053

1 files changed, 62 insertions, 0 deletions

diff --git a/cliff/tests/test_interactive.py b/cliff/tests/test_interactive.py
new file mode 100644
index 0000000..20306d1
--- /dev/null
+++ b/cliff/tests/test_interactive.py
@@ -0,0 +1,62 @@
+# -*- encoding: utf-8 -*-
+
+from cliff.interactive import InteractiveApp
+
+
+class FakeApp(object):
+    NAME = 'Fake'
+
+
+def make_interactive_app(*command_names):
+    fake_command_manager = [(x, None) for x in command_names]
+    return InteractiveApp(FakeApp, fake_command_manager,
+                          stdin=None, stdout=None)
+
+
+def _test_completenames(expecteds, prefix):
+    app = make_interactive_app('hips', 'hippo', 'nonmatching')
+    assert set(app.completenames(prefix)) == set(expecteds)
+
+
+def test_cmd2_completenames():
+    # cmd2.Cmd define do_help method
+    _test_completenames(['help'], 'he')
+
+
+def test_cliff_completenames():
+    _test_completenames(['hips', 'hippo'], 'hip')
+
+
+def test_no_completenames():
+    _test_completenames([], 'taz')
+
+
+def test_both_completenames():
+    # cmd2.Cmd define do_hi and do_history methods
+    _test_completenames(['hi', 'history', 'hips', 'hippo'], 'hi')
+
+
+def _test_completedefault(expecteds, line, begidx):
+    command_names = set(['show file', 'show folder', 'show  long', 'list all'])
+    app = make_interactive_app(*command_names)
+    observeds = app.completedefault(None, line, begidx, None)
+    assert set(observeds) == set(expecteds)
+    assert set([line[:begidx] + x for x in observeds]) <= command_names
+
+
+def test_empty_text_completedefault():
+    # line = 'show ' + begidx = 5 implies text = ''
+    _test_completedefault(['file', 'folder', ' long'], 'show ', 5)
+
+
+def test_nonempty_text_completedefault2():
+    # line = 'show f' + begidx = 6 implies text = 'f'
+    _test_completedefault(['file', 'folder'], 'show f', 5)
+
+
+def test_long_completedefault():
+    _test_completedefault(['long'], 'show  ', 6)
+
+
+def test_no_completedefault():
+    _test_completedefault([], 'taz ', 4)