dash_e: fixes #109 and #111

Behaviour of -e has not changed, but can be set by passing True or False
as a parameter multi_dash_e to tox/_config.py: prepare_parse()

This parameter should come from a user specifyable default value
for backwards compatibility. Default should preferable be True after
that is implemented.

_split_env() was factored out of class parseini to enable testing

The issue #111: error on specifying same env twice ("tox -e py27,py27")
fixed. Multiple specifications of the same environment result in
multiple invocation (this could also be selectable in a
configuration file)

3 files changed, 80 insertions, 4 deletions

diff --git a/tests/test_config.py b/tests/test_config.py
index ce3044d..6870af1 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -7,6 +7,7 @@ from textwrap import dedent
 import py
 from tox._config import IniReader, CommandParser
 from tox._config import parseconfig
+from tox._config import prepare_parse, _split_env
 
 class TestVenvConfig:
     def test_config_parsing_minimal(self, tmpdir, newconfig):
@@ -927,6 +928,42 @@ class TestCmdInvocation:
             "*ERROR*tox.ini*not*found*",
         ])
 
+
+class TestArgumentParser:
+
+    def test_dash_e_silent1(self):
+        parser = prepare_parse('testpkg', None)
+        args = parser.parse_args('-e py26 -e py33'.split())
+        envlist = _split_env(args.env)
+        assert envlist == ['py33']
+
+    def test_dash_e_silent2(self):
+        parser = prepare_parse('testpkg', None)
+        args = parser.parse_args('-e py26,py33'.split())
+        envlist = _split_env(args.env)
+        assert envlist == ['py26', 'py33']
+
+    def test_dash_e_silent3(self):
+        parser = prepare_parse('testpkg', None)
+        args = parser.parse_args('-e py26,py26'.split())
+        envlist = _split_env(args.env)
+        assert envlist == ['py26', 'py26']
+
+    def test_dash_e_warn(self, capsys):
+        parser = prepare_parse('testpkg', False)
+        args = parser.parse_args('-e py26,py32 -e py33'.split())
+        envlist = _split_env(args.env)
+        out, err = capsys.readouterr()
+        assert 'WARNING: previous optional argument "-e py26' in out
+        assert envlist == ['py33']
+
+    def test_dash_e_combine(self):
+        parser = prepare_parse('testpkg', True)
+        args = parser.parse_args('-e py26,py25,py33 -e py33,py27'.split())
+        envlist = _split_env(args.env)
+        assert envlist == ['py26', 'py25', 'py33', 'py33', 'py27']
+
+
 class TestCommandParser:
 
     def test_command_parser_for_word(self):
diff --git a/tox/_config.py b/tox/_config.py
index 0d86f10..16cd288 100644
--- a/tox/_config.py
+++ b/tox/_config.py
@@ -66,7 +66,25 @@ class CountAction(argparse.Action):
         else:
             setattr(namespace, self.dest, 0)
 
-def prepare_parse(pkgname):
+class CheckSingleStoreAction(argparse.Action):
+    """issue a warning when the store action is called multiple times"""
+    def __call__(self, parser, namespace, values, option_string=None):
+        if getattr(namespace, self.dest, None) is not None:
+            py.builtin.print_(
+                'WARNING: previous optional argument "' + option_string + " " +
+                getattr(namespace, self.dest) + '" overwritten by "' +
+                option_string + " " + values + '"')
+        setattr(namespace, self.dest, values)
+
+
+def prepare_parse(pkgname, multi_dash_e=None):
+    """setup ArgumentParser
+
+    multi_dash_e:
+        None -> silently ignore all but last -e pyXY option (old behaviour
+        False -> take last -e pyXY option, but warn on sys.stdout
+        True -> concatenate
+    """
     parser = argparse.ArgumentParser(description=__doc__,)
         #formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.pkgname = pkgname
@@ -83,7 +101,13 @@ def prepare_parse(pkgname):
     parser.add_argument("-c", action="store", default="tox.ini",
         dest="configfile",
         help="use the specified config file name.")
-    parser.add_argument("-e", action="store", dest="env",
+    if multi_dash_e is None:
+        dash_e_action = "store"
+    elif multi_dash_e is False:
+        dash_e_action = CheckSingleStoreAction
+    elif multi_dash_e is True:
+        dash_e_action = "append"
+    parser.add_argument("-e", action=dash_e_action, dest="env",
         metavar="envlist",
         help="work against specified environments (ALL selects all).")
     parser.add_argument("--notest", action="store_true", dest="notest",
@@ -346,9 +370,21 @@ class parseini:
             envlist = list(self.config.envconfigs)
             envlist.sort()
         else:
-            envlist = env.split(",")
+            envlist = _split_env(env)
         return envlist
 
+def _split_env(env):
+    """if handed a list, action="append" was used for -e """
+    envlist = []
+    if not isinstance(env, list):
+        env = [env]
+    for to_split in env:
+        for single_env in to_split.split(","):
+            # "remove True or", if not allowing multiple same runs, update tests
+            if True or single_env not in envlist:
+                envlist.append(single_env)
+    return envlist
+
 class DepConfig:
     def __init__(self, name, indexserver=None):
         self.name = name
diff --git a/tox/_venv.py b/tox/_venv.py
index 362009a..0c87319 100644
--- a/tox/_venv.py
+++ b/tox/_venv.py
@@ -325,7 +325,10 @@ class VirtualEnv(object):
             self.session.make_emptydir(self.envconfig.envtmpdir)
             cwd = self.envconfig.changedir
             for i, argv in enumerate(self.envconfig.commands):
-                message = "commands[%s] | %s" % (i, ' '.join(argv))
+                # have to make strings as _pcall changes argv[0] to a local()
+                # happens if the same environment is invoked twice
+                message = "commands[%s] | %s" % (i, ' '.join(
+                    [str(x) for x in argv]))
                 action.setactivity("runtests", message)
                 try:
                     self._pcall(argv, cwd=cwd, action=action, redirect=redirect)