More flexible version checking for compat tests.

We now check up to 4 components of the version number (e.g. 1.7.0.2).
Reorganized to make future changes easier. Added tests.

Change-Id: Id2f0bd5ba01cb77724d399d9c3a11af695eb2707

NEWS

@@ -73,6 +73,8 @@
 
   * Quiet logging output from web tests. (Dave Borowitz)
 
+  * More flexible version checking for compat tests. (Dave Borowitz)
+
  CLEANUP
 
   * Clean up file headers. (Dave Borowitz)

dulwich/tests/compat/test_utils.py

@@ -0,0 +1,91 @@
+# test_utils.py -- Tests for git compatibility utilities
+# Copyright (C) 2010 Google, Inc.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor,
+# Boston, MA  02110-1301, USA.
+
+"""Tests for git compatibility utilities."""
+
+from unittest import TestCase
+
+from dulwich.tests import (
+    TestSkipped,
+    )
+import utils
+
+
+class GitVersionTests(TestCase):
+
+    def setUp(self):
+        self._orig_run_git = utils.run_git
+        self._version_str = None  # tests can override to set stub version
+
+        def run_git(args, **unused_kwargs):
+            self.assertEqual(['--version'], args)
+            return 0, self._version_str
+        utils.run_git = run_git
+
+    def tearDown(self):
+        utils.run_git = self._orig_run_git
+
+    def test_git_version_none(self):
+        self._version_str = 'not a git version'
+        self.assertEqual(None, utils.git_version())
+
+    def test_git_version_3(self):
+        self._version_str = 'git version 1.6.6'
+        self.assertEqual((1, 6, 6, 0), utils.git_version())
+
+    def test_git_version_4(self):
+        self._version_str = 'git version 1.7.0.2'
+        self.assertEqual((1, 7, 0, 2), utils.git_version())
+
+    def test_git_version_extra(self):
+        self._version_str = 'git version 1.7.0.3.295.gd8fa2'
+        self.assertEqual((1, 7, 0, 3), utils.git_version())
+
+    def assertRequireSucceeds(self, required_version):
+        try:
+            utils.require_git_version(required_version)
+        except TestSkipped:
+            self.fail()
+
+    def assertRequireFails(self, required_version):
+        self.assertRaises(TestSkipped, utils.require_git_version,
+                          required_version)
+
+    def test_require_git_version(self):
+        try:
+            self._version_str = 'git version 1.6.6'
+            self.assertRequireSucceeds((1, 6, 6))
+            self.assertRequireSucceeds((1, 6, 6, 0))
+            self.assertRequireSucceeds((1, 6, 5))
+            self.assertRequireSucceeds((1, 6, 5, 99))
+            self.assertRequireFails((1, 7, 0))
+            self.assertRequireFails((1, 7, 0, 2))
+            self.assertRaises(ValueError, utils.require_git_version,
+                              (1, 6, 6, 0, 0))
+
+            self._version_str = 'git version 1.7.0.2'
+            self.assertRequireSucceeds((1, 6, 6))
+            self.assertRequireSucceeds((1, 6, 6, 0))
+            self.assertRequireSucceeds((1, 7, 0))
+            self.assertRequireSucceeds((1, 7, 0, 2))
+            self.assertRequireFails((1, 7, 0, 3))
+            self.assertRequireFails((1, 7, 1))
+        except TestSkipped, e:
+            # This test is designed to catch all TestSkipped exceptions.
+            self.fail('Test unexpectedly skipped: %s' % e)

dulwich/tests/compat/utils.py

@@ -35,6 +35,7 @@ from dulwich.tests import (
     )
 
 _DEFAULT_GIT = 'git'
+_VERSION_LEN = 4
 
 
 def git_version(git_path=_DEFAULT_GIT):
@@ -42,8 +43,8 @@ def git_version(git_path=_DEFAULT_GIT):
 
     :param git_path: Path to the git executable; defaults to the version in
         the system path.
-    :return: A tuple of ints of the form (major, minor, point), or None if no
-        git installation was found.
+    :return: A tuple of ints of the form (major, minor, point, sub-point), or
+        None if no git installation was found.
     """
     try:
         _, output = run_git(['--version'], git_path=git_path,
@@ -53,21 +54,40 @@ def git_version(git_path=_DEFAULT_GIT):
     version_prefix = 'git version '
     if not output.startswith(version_prefix):
         return None
-    output = output[len(version_prefix):]
-    nums = output.split('.')
-    if len(nums) == 2:
-        nums.add('0')
-    else:
-        nums = nums[:3]
-    try:
-        return tuple(int(x) for x in nums)
-    except ValueError:
-        return None
+
+    parts = output[len(version_prefix):].split('.')
+    nums = []
+    for part in parts:
+        try:
+            nums.append(int(part))
+        except ValueError:
+            break
+
+    while len(nums) < _VERSION_LEN:
+        nums.append(0)
+    return tuple(nums[:_VERSION_LEN])
 
 
 def require_git_version(required_version, git_path=_DEFAULT_GIT):
-    """Require git version >= version, or skip the calling test."""
+    """Require git version >= version, or skip the calling test.
+
+    :param required_version: A tuple of ints of the form (major, minor, point,
+        sub-point); ommitted components default to 0.
+    :param git_path: Path to the git executable; defaults to the version in
+        the system path.
+    :raise ValueError: if the required version tuple has too many parts.
+    :raise TestSkipped: if no suitable git version was found at the given path.
+    """
     found_version = git_version(git_path=git_path)
+    if len(required_version) > _VERSION_LEN:
+        raise ValueError('Invalid version tuple %s, expected %i parts' %
+                         (required_version, _VERSION_LEN))
+
+    required_version = list(required_version)
+    while len(found_version) < len(required_version):
+        required_version.append(0)
+    required_version = tuple(required_version)
+
     if found_version < required_version:
         required_version = '.'.join(map(str, required_version))
         found_version = '.'.join(map(str, found_version))