implement new experimental hooks for venv creation

8 files changed, 114 insertions, 53 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 3396dd7..4da6d0f 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -16,6 +16,13 @@
 - fix issue252: allow environment names with special characters.
   Thanks Julien Castets for initial PR and patience.
 
+- introduce experimental tox_testenv_create(venv, action) and 
+  tox_testenv_install_deps(venv, action) hooks to allow
+  plugins to do additional work on creation or installing
+  deps.  These hooks are experimental mainly because of
+  the involved "venv" object whose current public API is not 
+  fully guranteed.
+
 - internal: push some optional object creation into tests because
   tox core doesn't need it.
 
diff --git a/doc/plugins.txt b/doc/plugins.txt
index 8e7041c..be3665a 100644
--- a/doc/plugins.txt
+++ b/doc/plugins.txt
@@ -80,3 +80,9 @@ tox hook specifications and related API
 
 .. autoclass:: tox.config.TestenvConfig()
     :members:
+
+.. autoclass:: tox.venv.VirtualEnv()
+    :members:
+
+.. autoclass:: tox.session.Session()
+    :members:
diff --git a/tests/test_venv.py b/tests/test_venv.py
index 217b21e..4ab3b06 100644
--- a/tests/test_venv.py
+++ b/tests/test_venv.py
@@ -57,7 +57,7 @@ def test_create(monkeypatch, mocksession, newconfig):
     assert venv.path == envconfig.envdir
     assert not venv.path.check()
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) >= 1
     args = l[0].args
@@ -98,7 +98,7 @@ def test_create_sitepackages(monkeypatch, mocksession, newconfig):
     envconfig = config.envconfigs['site']
     venv = VirtualEnv(envconfig, session=mocksession)
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) >= 1
     args = l[0].args
@@ -108,7 +108,7 @@ def test_create_sitepackages(monkeypatch, mocksession, newconfig):
     envconfig = config.envconfigs['nosite']
     venv = VirtualEnv(envconfig, session=mocksession)
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) >= 1
     args = l[0].args
@@ -126,14 +126,14 @@ def test_install_deps_wildcard(newmocksession):
     """)
     venv = mocksession.getenv("py123")
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) == 1
     distshare = venv.session.config.distshare
     distshare.ensure("dep1-1.0.zip")
     distshare.ensure("dep1-1.1.zip")
 
-    venv.install_deps(action)
+    tox_testenv_install_deps(action=action, venv=venv)
     assert len(l) == 2
     args = l[-1].args
     assert l[-1].cwd == venv.envconfig.config.toxinidir
@@ -159,11 +159,11 @@ def test_install_downloadcache(newmocksession, monkeypatch, tmpdir, envdc):
     """)
     venv = mocksession.getenv("py123")
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) == 1
 
-    venv.install_deps(action)
+    tox_testenv_install_deps(action=action, venv=venv)
     assert len(l) == 2
     args = l[-1].args
     assert l[-1].cwd == venv.envconfig.config.toxinidir
@@ -189,12 +189,12 @@ def test_install_deps_indexserver(newmocksession):
     """)
     venv = mocksession.getenv('py123')
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) == 1
     l[:] = []
 
-    venv.install_deps(action)
+    tox_testenv_install_deps(action=action, venv=venv)
     # two different index servers, two calls
     assert len(l) == 3
     args = " ".join(l[0].args)
@@ -218,12 +218,12 @@ def test_install_deps_pre(newmocksession):
     """)
     venv = mocksession.getenv('python')
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) == 1
     l[:] = []
 
-    venv.install_deps(action)
+    tox_testenv_install_deps(action=action, venv=venv)
     assert len(l) == 1
     args = " ".join(l[0].args)
     assert "--pre " in args
@@ -355,7 +355,7 @@ def test_install_python3(tmpdir, newmocksession):
     """)
     venv = mocksession.getenv('py123')
     action = mocksession.newaction(venv, "getenv")
-    venv.create(action)
+    tox_testenv_create(action=action, venv=venv)
     l = mocksession._pcalls
     assert len(l) == 1
     args = l[0].args
@@ -649,3 +649,26 @@ def test_ignore_outcome_failing_cmd(newmocksession):
     assert venv.status == "ignored failed command"
     mocksession.report.expect("warning", "*command failed but result from "
                                          "testenv is ignored*")
+
+
+def test_tox_testenv_create(newmocksession):
+    l = []
+
+    class Plugin:
+        @hookimpl
+        def tox_testenv_create(self, action, venv):
+            l.append(1)
+
+        @hookimpl
+        def tox_testenv_install_deps(self, action, venv):
+            l.append(2)
+
+    mocksession = newmocksession([], """
+        [testenv]
+        commands=testenv_fail
+        ignore_outcome=True
+    """, plugins=[Plugin()])
+
+    venv = mocksession.getenv('python')
+    venv.update(action=mocksession.newaction(venv, "getenv"))
+    assert l == [1, 2]
diff --git a/tox/_pytestplugin.py b/tox/_pytestplugin.py
index ee85acc..f15d2ec 100644
--- a/tox/_pytestplugin.py
+++ b/tox/_pytestplugin.py
@@ -31,7 +31,7 @@ def pytest_report_header():
 
 @pytest.fixture
 def newconfig(request, tmpdir):
-    def newconfig(args, source=None):
+    def newconfig(args, source=None, plugins=()):
         if source is None:
             source = args
             args = []
@@ -40,7 +40,7 @@ def newconfig(request, tmpdir):
         p.write(s)
         old = tmpdir.chdir()
         try:
-            return parseconfig(args)
+            return parseconfig(args, plugins=plugins)
         finally:
             old.chdir()
     return newconfig
@@ -168,9 +168,8 @@ def newmocksession(request):
     mocksession = request.getfuncargvalue("mocksession")
     newconfig = request.getfuncargvalue("newconfig")
 
-    def newmocksession(args, source):
-        config = newconfig(args, source)
-        mocksession.config = config
+    def newmocksession(args, source, plugins=()):
+        mocksession.config = newconfig(args, source, plugins=plugins)
         return mocksession
     return newmocksession
 
diff --git a/tox/config.py b/tox/config.py
index d34a597..ad80269 100644
--- a/tox/config.py
+++ b/tox/config.py
@@ -29,13 +29,17 @@ hookimpl = pluggy.HookimplMarker("tox")
 _dummy = object()
 
 
-def get_plugin_manager():
+def get_plugin_manager(plugins=()):
     # initialize plugin manager
+    import tox.venv
     pm = pluggy.PluginManager("tox")
     pm.add_hookspecs(hookspecs)
     pm.register(tox.config)
     pm.register(tox.interpreters)
+    pm.register(tox.venv)
     pm.load_setuptools_entrypoints("tox")
+    for plugin in plugins:
+        pm.register(plugin)
     pm.check_pending()
     return pm
 
@@ -186,7 +190,7 @@ class InstallcmdOption:
         return value
 
 
-def parseconfig(args=None):
+def parseconfig(args=None, plugins=()):
     """
     :param list[str] args: Optional list of arguments.
     :type pkg: str
@@ -194,7 +198,7 @@ def parseconfig(args=None):
     :raise SystemExit: toxinit file is not found
     """
 
-    pm = get_plugin_manager()
+    pm = get_plugin_manager(plugins)
 
     if args is None:
         args = sys.argv[1:]
diff --git a/tox/hookspecs.py b/tox/hookspecs.py
index 103bda5..36c539c 100644
--- a/tox/hookspecs.py
+++ b/tox/hookspecs.py
@@ -30,3 +30,14 @@ def tox_get_python_executable(envconfig):
     per-testenv configuration, notably the ``.envname`` and ``.basepython``
     setting.
     """
+
+
+@hookspec
+def tox_testenv_create(venv, action):
+    """ [experimental] perform creation action for this venv.
+    """
+
+
+@hookspec
+def tox_testenv_install_deps(venv, action):
+    """ [experimental] perform install dependencies action for this venv.  """
diff --git a/tox/session.py b/tox/session.py
index e5e654b..ffb52d6 100644
--- a/tox/session.py
+++ b/tox/session.py
@@ -313,6 +313,8 @@ class Reporter(object):
 
 
 class Session:
+    """ (unstable API).  the session object that ties
+    together configuration, reporting, venv creation, testing. """
 
     def __init__(self, config, popen=subprocess.Popen, Report=Reporter):
         self.config = config
diff --git a/tox/venv.py b/tox/venv.py
index bed7fb7..2e46098 100644
--- a/tox/venv.py
+++ b/tox/venv.py
@@ -5,7 +5,7 @@ import re
 import codecs
 import py
 import tox
-from .config import DepConfig
+from .config import DepConfig, hookimpl
 
 
 class CreationConfig:
@@ -58,6 +58,10 @@ class VirtualEnv(object):
         self.session = session
 
     @property
+    def hook(self):
+        return self.envconfig.config.pluginmanager.hook
+
+    @property
     def path(self):
         """ Path to environment base dir. """
         return self.envconfig.envdir
@@ -76,7 +80,8 @@ class VirtualEnv(object):
 
     def getcommandpath(self, name, venv=True, cwd=None):
         """ return absolute path (str or localpath) for specified
-        command name.  If venv is True we will check if the
+        command name.  If it's a localpath we will rewrite it as
+        as a relative path.  If venv is True we will check if the
         command is coming from the venv or is whitelisted to come
         from external. """
         name = str(name)
@@ -138,13 +143,14 @@ class VirtualEnv(object):
         else:
             action.setactivity("recreate", self.envconfig.envdir)
         try:
-            self.create(action)
+            self.hook.tox_testenv_create(action=action, venv=self)
+            self.just_created = True
         except tox.exception.UnsupportedInterpreter:
             return sys.exc_info()[1]
         except tox.exception.InterpreterNotFound:
             return sys.exc_info()[1]
         try:
-            self.install_deps(action)
+            self.hook.tox_testenv_install_deps(action=action, venv=self)
         except tox.exception.InvocationError:
             v = sys.exc_info()[1]
             return "could not install deps %s; v = %r" % (
@@ -180,28 +186,6 @@ class VirtualEnv(object):
     def matching_platform(self):
         return re.match(self.envconfig.platform, sys.platform)
 
-    def create(self, action):
-        # if self.getcommandpath("activate").dirpath().check():
-        #    return
-        config_interpreter = self.getsupportedinterpreter()
-        args = [sys.executable, '-m', 'virtualenv']
-        if self.envconfig.sitepackages:
-            args.append('--system-site-packages')
-        # add interpreter explicitly, to prevent using
-        # default (virtualenv.ini)
-        args.extend(['--python', str(config_interpreter)])
-        # if sys.platform == "win32":
-        #    f, path, _ = py.std.imp.find_module("virtualenv")
-        #    f.close()
-        #    args[:1] = [str(config_interpreter), str(path)]
-        # else:
-        self.session.make_emptydir(self.path)
-        basepath = self.path.dirpath()
-        basepath.ensure(dir=1)
-        args.append(self.path.basename)
-        self._pcall(args, venv=False, action=action, cwd=basepath)
-        self.just_created = True
-
     def finish(self):
         self._getliveconfig().writeconfig(self.path_config)
 
@@ -244,13 +228,6 @@ class VirtualEnv(object):
             extraopts = ['-U', '--no-deps']
         self._install([sdistpath], extraopts=extraopts, action=action)
 
-    def install_deps(self, action):
-        deps = self._getresolvedeps()
-        if deps:
-            depinfo = ", ".join(map(str, deps))
-            action.setactivity("installdeps", "%s" % depinfo)
-            self._install(deps, action=action)
-
     def _installopts(self, indexserver):
         l = []
         if indexserver:
@@ -390,3 +367,35 @@ def getdigest(path):
     if not path.check(file=1):
         return "0" * 32
     return path.computehash()
+
+
+@hookimpl
+def tox_testenv_create(venv, action):
+    # if self.getcommandpath("activate").dirpath().check():
+    #    return
+    config_interpreter = venv.getsupportedinterpreter()
+    args = [sys.executable, '-m', 'virtualenv']
+    if venv.envconfig.sitepackages:
+        args.append('--system-site-packages')
+    # add interpreter explicitly, to prevent using
+    # default (virtualenv.ini)
+    args.extend(['--python', str(config_interpreter)])
+    # if sys.platform == "win32":
+    #    f, path, _ = py.std.imp.find_module("virtualenv")
+    #    f.close()
+    #    args[:1] = [str(config_interpreter), str(path)]
+    # else:
+    venv.session.make_emptydir(venv.path)
+    basepath = venv.path.dirpath()
+    basepath.ensure(dir=1)
+    args.append(venv.path.basename)
+    venv._pcall(args, venv=False, action=action, cwd=basepath)
+
+
+@hookimpl
+def tox_testenv_install_deps(venv, action):
+    deps = venv._getresolvedeps()
+    if deps:
+        depinfo = ", ".join(map(str, deps))
+        action.setactivity("installdeps", "%s" % depinfo)
+        venv._install(deps, action=action)