morphlib: Add MorphologyFinder class

MorphologyFinder is a small wrapper on top of GitDirectory that
allows the inspection of morphologies in the repository.

Its purpose is to isolate the logic for reading morphologies into one
place.

It is used by passing a GitDirectory and optionally a ref to the
MorpholgyFinder constructor, then list_morphologies and read_morphology
may be used.

The ref is passed directly to the GitDirectory, so its semantics for
a ref of None or omitted are used. i.e. It uses the working tree.

Ref resolving is deferred until a morphology is listed or read, so
it will not raise an exception for an invalid ref until then.

1 files changed, 111 insertions, 0 deletions

diff --git a/morphlib/morphologyfinder_tests.py b/morphlib/morphologyfinder_tests.py
new file mode 100644
index 00000000..ff83ccff
--- /dev/null
+++ b/morphlib/morphologyfinder_tests.py
@@ -0,0 +1,111 @@
+# Copyright (C) 2013  Codethink Limited
+#
+# 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; version 2 of the License.
+#
+# 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.
+#
+# =*= License: GPL-2 =*=
+
+
+import os
+import shutil
+import tempfile
+import unittest
+
+import morphlib
+
+
+class MorphologyFinderTests(unittest.TestCase):
+
+    def setUp(self):
+        self.tempdir = tempfile.mkdtemp()
+        self.dirname = os.path.join(self.tempdir, 'repo')
+        os.mkdir(self.dirname)
+        gd = morphlib.gitdir.init(self.dirname)
+        for fn in ('foo', 'bar.morph', 'baz.morph', 'quux'):
+            with open(os.path.join(self.dirname, fn), "w") as f:
+                f.write('dummy morphology text')
+        gd._runcmd(['git', 'add', '.'])
+        gd._runcmd(['git', 'commit', '-m', 'Initial commit'])
+
+        # Changes for difference between commited and work tree
+        newmorphpath = os.path.join(self.dirname, 'foo.morph')
+        os.unlink(os.path.join(self.dirname, 'foo'))
+        with open(newmorphpath, 'w') as f:
+            f.write("altered morphology text")
+
+        # Changes for bare repository
+        self.mirror = os.path.join(self.tempdir, 'mirror')
+        gd._runcmd(['git', 'clone', '--mirror', self.dirname, self.mirror])
+
+    def tearDown(self):
+        shutil.rmtree(self.tempdir)
+
+    def test_list_morphs_in_HEAD(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd, 'HEAD')
+        self.assertEqual(sorted(mf.list_morphologies()),
+                         ['bar', 'baz'])
+
+    def test_list_morphs_in_master(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd, 'master')
+        self.assertEqual(sorted(mf.list_morphologies()),
+                         ['bar', 'baz'])
+
+    def test_list_morphs_raises_with_invalid_ref(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd, 'invalid_ref')
+        self.assertRaises(morphlib.gitdir.InvalidRefError,
+                          mf.list_morphologies)
+
+    def test_list_morphs_in_work_tree(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd)
+        self.assertEqual(sorted(mf.list_morphologies()),
+                         ['bar', 'baz', 'foo'])
+
+    def test_list_morphs_raises_no_worktree_no_ref(self):
+        gd = morphlib.gitdir.GitDirectory(self.mirror)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd)
+        self.assertRaises(morphlib.gitdir.NoWorkingTreeError,
+                          mf.list_morphologies)
+
+    def test_read_morph_in_HEAD(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd, 'HEAD')
+        self.assertEqual(mf.read_morphology('bar')[0],
+                         "dummy morphology text")
+
+    def test_read_morph_in_master(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd, 'master')
+        self.assertEqual(mf.read_morphology('bar')[0],
+                         "dummy morphology text")
+
+    def test_read_morph_raises_with_invalid_ref(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd, 'invalid_ref')
+        self.assertRaises(morphlib.gitdir.InvalidRefError,
+                          mf.read_morphology, 'bar')
+
+    def test_read_morph_in_work_tree(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd)
+        self.assertEqual(mf.read_morphology('foo')[0],
+                         "altered morphology text")
+
+    def test_read_morph_raises_no_worktree_no_ref(self):
+        gd = morphlib.gitdir.GitDirectory(self.mirror)
+        mf = morphlib.morphologyfinder.MorphologyFinder(gd)
+        self.assertRaises(morphlib.gitdir.NoWorkingTreeError,
+                          mf.read_morphology, 'bar')