merged and slightly modified PR81: new option --force-dep which allows to

override tox.ini specified dependencies in setuptools-style.
For example "--force-dep 'django<1.6'" will make sure
that any environment using "django" as a dependency will
get the latest 1.5 release.  Thanks Bruno Oliveria for
the complete PR.

3 files changed, 24 insertions, 12 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 439d88f..1736649 100755
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,13 @@
 1.6.2.dev
 ---------
 
+- merged PR81: new option --force-dep which allows to 
+  override tox.ini specified dependencies in setuptools-style.
+  For example "--force-dep 'django<1.6'" will make sure
+  that any environment using "django" as a dependency will 
+  get the latest 1.5 release.  Thanks Bruno Oliveria for 
+  the complete PR.
+  
 - merged PR125: tox now sets "PYTHONHASHSEED" to a random value
   and offers a "--hashseed" option to repeat a test run with a specific seed.
   You can also use --hashsheed=notset to instruct tox to leave the value
@@ -21,8 +28,8 @@
 
 - fix issue129: tox now uses Popen(..., universal_newlines=True) to force 
   creation of unicode stdout/stderr streams.  fixes a problem on specific
-  platform configs when creating virtualenvs with Python3.3. Thanks Jorgen Schäfer
-  or investigation and solution sketch.
+  platform configs when creating virtualenvs with Python3.3. Thanks
+  Jorgen Schäfer or investigation and solution sketch.
 
 - fix issue128: enable full substitution in install_command,
   thanks for the PR to Ronald Evers
diff --git a/tests/test_config.py b/tests/test_config.py
index 517ec29..84e4366 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -65,7 +65,7 @@ class TestVenvConfig:
     def test_force_dep_version(self, initproj):
         """
         Make sure we can override dependencies configured in tox.ini when using the command line option
-        --force-dep-version.
+        --force-dep.
         """
         initproj("example123-0.5", filedefs={
             'tox.ini': '''
@@ -80,8 +80,10 @@ class TestVenvConfig:
             '''
         })
         config = parseconfig(
-            ['--force-dep-version=dep1==1.5', '--force-dep-version=dep2==2.1', '--force-dep-version=dep3==3.0'])
-        assert config.option.force_dep_version == ['dep1==1.5', 'dep2==2.1', 'dep3==3.0']
+            ['--force-dep=dep1==1.5', '--force-dep=dep2==2.1',
+             '--force-dep=dep3==3.0'])
+        assert config.option.force_dep== [
+            'dep1==1.5', 'dep2==2.1', 'dep3==3.0']
         assert [str(x) for x in config.envconfigs['python'].deps] == [
             'dep1==1.5', 'dep2==2.1', 'dep3==3.0', 'dep4==4.0',
         ]
@@ -1194,7 +1196,8 @@ class TestCmdInvocation:
             r'*deps=*dep1==2.3, dep2*',
         ])
         # override dep1 specific version, and force version for dep2
-        result = cmd.run("tox", "--showconfig", "--force-dep-version=dep1", "--force-dep-version=dep2==5.0")
+        result = cmd.run("tox", "--showconfig", "--force-dep=dep1",
+                         "--force-dep=dep2==5.0")
         assert result.ret == 0
         result.stdout.fnmatch_lines([
             r'*deps=*dep1, dep2==5.0*',
diff --git a/tox/_config.py b/tox/_config.py
index 0348080..c20e251 100644
--- a/tox/_config.py
+++ b/tox/_config.py
@@ -125,10 +125,11 @@ def prepare_parse(pkgname):
         help="set PYTHONHASHSEED to SEED before running commands.  "
              "Defaults to a random integer in the range 1 to 4294967295.  "
              "Passing 'noset' suppresses this behavior.")
-    parser.add_argument("--force-dep-version", action="append",
-        metavar="DEP==VER", default=None,
+    parser.add_argument("--force-dep", action="append",
+        metavar="REQ", default=None,
         help="Forces a certain version of one of the dependencies "
-             "when configuring the virtual environment.")
+             "when configuring the virtual environment. REQ Examples "
+             "'pytest<2.4' or 'django>=1.6'.")
     parser.add_argument("args", nargs="*",
         help="additional arguments available to command positional substitution")
     return parser
@@ -400,9 +401,9 @@ class parseini:
         :param config: Config instance
         :return: the new dependency that should be used for virtual environments
         """
-        if not config.option.force_dep_version:
+        if not config.option.force_dep:
             return name
-        for forced_dep in config.option.force_dep_version:
+        for forced_dep in config.option.force_dep:
             if self._is_same_dep(forced_dep, name):
                 return forced_dep
         return name
@@ -410,7 +411,8 @@ class parseini:
     @classmethod
     def _is_same_dep(cls, dep1, dep2):
         """
-        Returns True if both dependency definitions refer to the same package, even if versions differ.
+        Returns True if both dependency definitions refer to the
+        same package, even if versions differ.
         """
         dep1_name = pkg_resources.Requirement.parse(dep1).project_name
         dep2_name = pkg_resources.Requirement.parse(dep2).project_name