Added version_info property to git command. Its cached and efficient, including test

Author: Byron

git/cmd.py

@@ -5,7 +5,10 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 import os, sys
-from util import *
+from util import (
+					LazyMixin, 
+					stream_copy
+				)
 from exc import GitCommandError
 
 from subprocess import (
@@ -26,7 +29,7 @@
 def dashify(string):
 	return string.replace('_', '-')
 
-class Git(object):
+class Git(LazyMixin):
 	"""
 	The Git class manages communication with the Git binary.
 	
@@ -41,7 +44,7 @@ class Git(object):
 		of the command to stdout.
 		Set its value to 'full' to see details about the returned values.
 	"""
-	__slots__ = ("_working_dir", "cat_file_all", "cat_file_header")
+	__slots__ = ("_working_dir", "cat_file_all", "cat_file_header", "_version_info")
 
 	# CONFIGURATION
 	# The size in bytes read from stdout when copying git's output to another stream
@@ -214,14 +217,30 @@ def __getattr__(self, name):
 		"""A convenience method as it allows to call the command as if it was 
 		an object.
 		:return: Callable object that will execute call _call_process with your arguments."""
-		if name[:1] == '_':
-			raise AttributeError(name)
+		if name[0] == '_':
+			return LazyMixin.__getattr__(self, name)
 		return lambda *args, **kwargs: self._call_process(name, *args, **kwargs)
 
+	def _set_cache_(self, attr):
+		if attr == '_version_info':
+			version_numbers = self._call_process('version').rpartition(' ')[2]
+			self._version_info = tuple(int(n) for n in version_numbers.split('.'))
+		else:
+			super(Git, self)._set_cache_(attr)
+		#END handle version info
+			
+
 	@property
 	def working_dir(self):
 		""":return: Git directory we are working on"""
 		return self._working_dir
+		
+	@property
+	def version_info(self):
+		""":return: tuple(int, ...) tuple with integers representing the major, minor
+			and additional version numbers as parsed from git version.
+			This value is generated on demand and is cached"""
+		return self._version_info
 
 	def execute(self, command,
 				istream=None,

git/test/test_git.py

@@ -5,80 +5,96 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 import os, sys
-from git.test.lib import *
+from git.test.lib import (
+							TestBase, 
+							patch_object, 
+							raises,
+							assert_equal,
+							assert_true,
+							assert_match,
+							fixture_path
+						)
 from git import Git, GitCommandError
 
-class TestGit(TestCase):
-    
-    @classmethod
-    def setUpAll(cls):
-        cls.git = Git(GIT_REPO)
+class TestGit(TestBase):
+	
+	@classmethod
+	def setUpAll(cls):
+		super(TestGit, cls).setUpAll()
+		cls.git = Git(cls.rorepo.working_dir)
 
-    @patch_object(Git, 'execute')
-    def test_call_process_calls_execute(self, git):
-        git.return_value = ''
-        self.git.version()
-        assert_true(git.called)
-        assert_equal(git.call_args, ((['git', 'version'],), {}))
+	@patch_object(Git, 'execute')
+	def test_call_process_calls_execute(self, git):
+		git.return_value = ''
+		self.git.version()
+		assert_true(git.called)
+		assert_equal(git.call_args, ((['git', 'version'],), {}))
 
-    @raises(GitCommandError)
-    def test_it_raises_errors(self):
-        self.git.this_does_not_exist()
+	@raises(GitCommandError)
+	def test_it_raises_errors(self):
+		self.git.this_does_not_exist()
 
 
-    def test_it_transforms_kwargs_into_git_command_arguments(self):
-        assert_equal(["-s"], self.git.transform_kwargs(**{'s': True}))
-        assert_equal(["-s5"], self.git.transform_kwargs(**{'s': 5}))
+	def test_it_transforms_kwargs_into_git_command_arguments(self):
+		assert_equal(["-s"], self.git.transform_kwargs(**{'s': True}))
+		assert_equal(["-s5"], self.git.transform_kwargs(**{'s': 5}))
 
-        assert_equal(["--max-count"], self.git.transform_kwargs(**{'max_count': True}))
-        assert_equal(["--max-count=5"], self.git.transform_kwargs(**{'max_count': 5}))
+		assert_equal(["--max-count"], self.git.transform_kwargs(**{'max_count': True}))
+		assert_equal(["--max-count=5"], self.git.transform_kwargs(**{'max_count': 5}))
 
-        assert_equal(["-s", "-t"], self.git.transform_kwargs(**{'s': True, 't': True}))
+		assert_equal(["-s", "-t"], self.git.transform_kwargs(**{'s': True, 't': True}))
 
-    def test_it_executes_git_to_shell_and_returns_result(self):
-        assert_match('^git version [\d\.]{2}.*$', self.git.execute(["git","version"]))
+	def test_it_executes_git_to_shell_and_returns_result(self):
+		assert_match('^git version [\d\.]{2}.*$', self.git.execute(["git","version"]))
 
-    def test_it_accepts_stdin(self):
-        filename = fixture_path("cat_file_blob")
-        fh = open(filename, 'r')
-        assert_equal("70c379b63ffa0795fdbfbc128e5a2818397b7ef8",
-                     self.git.hash_object(istream=fh, stdin=True))
-        fh.close()
+	def test_it_accepts_stdin(self):
+		filename = fixture_path("cat_file_blob")
+		fh = open(filename, 'r')
+		assert_equal("70c379b63ffa0795fdbfbc128e5a2818397b7ef8",
+					 self.git.hash_object(istream=fh, stdin=True))
+		fh.close()
 
-    @patch_object(Git, 'execute')
-    def test_it_ignores_false_kwargs(self, git):
-        # this_should_not_be_ignored=False implies it *should* be ignored
-        output = self.git.version(pass_this_kwarg=False)
-        assert_true("pass_this_kwarg" not in git.call_args[1])
-        
-    def test_persistent_cat_file_command(self):
-        # read header only
-        import subprocess as sp
-        hexsha = "b2339455342180c7cc1e9bba3e9f181f7baa5167"
-        g = self.git.cat_file(batch_check=True, istream=sp.PIPE,as_process=True)
-        g.stdin.write("b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
-        g.stdin.flush()
-        obj_info = g.stdout.readline()
-        
-        # read header + data
-        g = self.git.cat_file(batch=True, istream=sp.PIPE,as_process=True)
-        g.stdin.write("b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
-        g.stdin.flush()
-        obj_info_two = g.stdout.readline()
-        assert obj_info == obj_info_two
-        
-        # read data - have to read it in one large chunk
-        size = int(obj_info.split()[2])
-        data = g.stdout.read(size)
-        terminating_newline = g.stdout.read(1)
-        
-        # now we should be able to read a new object
-        g.stdin.write("b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
-        g.stdin.flush()
-        assert g.stdout.readline() == obj_info
-        
-        
-        # same can be achived using the respective command functions
-        hexsha, typename, size =  self.git.get_object_header(hexsha)
-        hexsha, typename_two, size_two, data = self.git.get_object_data(hexsha)
-        assert typename == typename_two and size == size_two
+	@patch_object(Git, 'execute')
+	def test_it_ignores_false_kwargs(self, git):
+		# this_should_not_be_ignored=False implies it *should* be ignored
+		output = self.git.version(pass_this_kwarg=False)
+		assert_true("pass_this_kwarg" not in git.call_args[1])
+		
+	def test_persistent_cat_file_command(self):
+		# read header only
+		import subprocess as sp
+		hexsha = "b2339455342180c7cc1e9bba3e9f181f7baa5167"
+		g = self.git.cat_file(batch_check=True, istream=sp.PIPE,as_process=True)
+		g.stdin.write("b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
+		g.stdin.flush()
+		obj_info = g.stdout.readline()
+		
+		# read header + data
+		g = self.git.cat_file(batch=True, istream=sp.PIPE,as_process=True)
+		g.stdin.write("b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
+		g.stdin.flush()
+		obj_info_two = g.stdout.readline()
+		assert obj_info == obj_info_two
+		
+		# read data - have to read it in one large chunk
+		size = int(obj_info.split()[2])
+		data = g.stdout.read(size)
+		terminating_newline = g.stdout.read(1)
+		
+		# now we should be able to read a new object
+		g.stdin.write("b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
+		g.stdin.flush()
+		assert g.stdout.readline() == obj_info
+		
+		
+		# same can be achived using the respective command functions
+		hexsha, typename, size =  self.git.get_object_header(hexsha)
+		hexsha, typename_two, size_two, data = self.git.get_object_data(hexsha)
+		assert typename == typename_two and size == size_two
+		
+	def test_version(self):
+		v = self.git.version_info
+		assert isinstance(v, tuple)
+		for n in v:
+			assert isinstance(n, int)
+		#END verify number types