GitDir: Add GitDirectory.commit_tree() method

This is used to create commit objects. This is used by build without
commit to provide the behind-the-scenes history.

2 files changed, 53 insertions, 0 deletions

diff --git a/morphlib/gitdir.py b/morphlib/gitdir.py
index 9020506a..aad507a6 100644
--- a/morphlib/gitdir.py
+++ b/morphlib/gitdir.py
@@ -17,6 +17,7 @@
 
 
 import cliapp
+import itertools
 import os
 
 import morphlib
@@ -242,6 +243,25 @@ class GitDirectory(object):
         return self._runcmd(['git', 'hash-object', '-t', 'blob',
                              '-w', '--stdin'], **kwargs).strip()
 
+    def commit_tree(self, tree, parent, message, **kwargs):
+        '''Create a commit'''
+        # NOTE: Will need extension for 0 or N parents.
+        env = {}
+        for who, info in itertools.product(('committer', 'author'),
+                                           ('name', 'email')):
+            argname = '%s_%s' % (who, info)
+            envname = 'GIT_%s_%s' % (who.upper(), info.upper())
+            if argname in kwargs:
+                env[envname] = kwargs[argname]
+        for who in ('committer', 'author'):
+            argname = '%s_date' % who
+            envname = 'GIT_%s_DATE' % who.upper()
+            if argname in kwargs:
+                env[envname] = kwargs[argname].isoformat()
+        return self._runcmd(['git', 'commit-tree', tree,
+                             '-p', parent, '-m', message],
+                            env=env).strip()
+
 
 def init(dirname):
     '''Initialise a new git repository.'''
diff --git a/morphlib/gitdir_tests.py b/morphlib/gitdir_tests.py
index a56df7c8..3063f5cf 100644
--- a/morphlib/gitdir_tests.py
+++ b/morphlib/gitdir_tests.py
@@ -16,6 +16,7 @@
 # =*= License: GPL-2 =*=
 
 
+import datetime
 import os
 import shutil
 import tempfile
@@ -178,3 +179,35 @@ class GitDirectoryContentsTests(unittest.TestCase):
         with open(os.path.join(self.tempdir, 'blob'), 'r') as f:
             sha1 = gd.store_blob(f)
         self.assertEqual('test string', gd.get_blob_contents(sha1))
+
+    def test_commit_tree(self):
+        gd = morphlib.gitdir.GitDirectory(self.dirname)
+        parent = gd.resolve_ref_to_commit(gd.HEAD)
+        tree = gd.resolve_ref_to_tree(parent)
+        aname = 'Author Name'
+        aemail = 'author@email'
+        cname = 'Committer Name'
+        cemail = 'committer@email'
+        pseudo_now = datetime.datetime.fromtimestamp(683074800)
+
+        now_str = "683074800"
+        message= 'MESSAGE'
+        expected = [
+            "tree %(tree)s",
+            "parent %(parent)s",
+            "author %(aname)s <%(aemail)s> %(now_str)s +0000",
+            "committer %(cname)s <%(cemail)s> %(now_str)s +0000",
+            "",
+            "%(message)s",
+            "",
+        ]
+        expected = [l % locals() for l in expected]
+        commit = gd.commit_tree(tree, parent, message=message,
+                                committer_name=cname,
+                                committer_email=cemail,
+                                committer_date=pseudo_now,
+                                author_name=aname,
+                                author_email=aemail,
+                                author_date=pseudo_now,
+                                )
+        self.assertEqual(expected, gd.get_commit_contents(commit).split('\n'))