manifest_xml: refactor manifest parsing from client management

We conflate the manifest & parsing logic with the management of the
repo client checkout in a single class.  This makes testing just one
part (the manifest parsing) hard as it requires a full checkout too.

Start splitting the two apart into separate classes to make it easy
to reason about & test.

Change-Id: Iaf897c93db9c724baba6044bfe7a589c024523b2
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/288682
Reviewed-by: Michael Mortensen <mmortensen@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

1 files changed, 55 insertions, 25 deletions

diff --git a/manifest_xml.py b/manifest_xml.py
index e1ef330f..95c67d73 100644
--- a/manifest_xml.py
+++ b/manifest_xml.py
@@ -187,12 +187,24 @@ class _XmlRemote(object):
 class XmlManifest(object):
   """manages the repo configuration file"""
 
-  def __init__(self, repodir):
+  def __init__(self, repodir, manifest_file, local_manifests=None):
+    """Initialize.
+
+    Args:
+      repodir: Path to the .repo/ dir for holding all internal checkout state.
+          It must be in the top directory of the repo client checkout.
+      manifest_file: Full path to the manifest file to parse.  This will usually
+          be |repodir|/|MANIFEST_FILE_NAME|.
+      local_manifests: Full path to the directory of local override manifests.
+          This will usually be |repodir|/|LOCAL_MANIFESTS_DIR_NAME|.
+    """
+    # TODO(vapier): Move this out of this class.
+    self.globalConfig = GitConfig.ForUser()
+
     self.repodir = os.path.abspath(repodir)
     self.topdir = os.path.dirname(self.repodir)
-    self.manifestFile = os.path.join(self.repodir, MANIFEST_FILE_NAME)
-    self.globalConfig = GitConfig.ForUser()
-    self.isGitcClient = False
+    self.manifestFile = manifest_file
+    self.local_manifests = local_manifests
     self._load_local_manifests = True
 
     self.repoProject = MetaProject(self, 'repo',
@@ -602,20 +614,11 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
       nodes.append(self._ParseManifestXml(self.manifestFile,
                                           self.manifestProject.worktree))
 
-      if self._load_local_manifests:
-        if os.path.exists(os.path.join(self.repodir, LOCAL_MANIFEST_NAME)):
-          print('error: %s is not supported; put local manifests in `%s`'
-                'instead' % (LOCAL_MANIFEST_NAME,
-                             os.path.join(self.repodir, LOCAL_MANIFESTS_DIR_NAME)),
-                file=sys.stderr)
-          sys.exit(1)
-
-        local_dir = os.path.abspath(os.path.join(self.repodir,
-                                                 LOCAL_MANIFESTS_DIR_NAME))
+      if self._load_local_manifests and self.local_manifests:
         try:
-          for local_file in sorted(platform_utils.listdir(local_dir)):
+          for local_file in sorted(platform_utils.listdir(self.local_manifests)):
             if local_file.endswith('.xml'):
-              local = os.path.join(local_dir, local_file)
+              local = os.path.join(self.local_manifests, local_file)
               nodes.append(self._ParseManifestXml(local, self.repodir))
         except OSError:
           pass
@@ -1253,15 +1256,7 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
 
 
 class GitcManifest(XmlManifest):
-
-  def __init__(self, repodir, gitc_client_name):
-    """Initialize the GitcManifest object."""
-    super(GitcManifest, self).__init__(repodir)
-    self.isGitcClient = True
-    self.gitc_client_name = gitc_client_name
-    self.gitc_client_dir = os.path.join(gitc_utils.get_gitc_manifest_dir(),
-                                        gitc_client_name)
-    self.manifestFile = os.path.join(self.gitc_client_dir, '.manifest')
+  """Parser for GitC (git-in-the-cloud) manifests."""
 
   def _ParseProject(self, node, parent=None):
     """Override _ParseProject and add support for GITC specific attributes."""
@@ -1272,3 +1267,38 @@ class GitcManifest(XmlManifest):
     """Output GITC Specific Project attributes"""
     if p.old_revision:
       e.setAttribute('old-revision', str(p.old_revision))
+
+
+class RepoClient(XmlManifest):
+  """Manages a repo client checkout."""
+
+  def __init__(self, repodir, manifest_file=None):
+    self.isGitcClient = False
+
+    if os.path.exists(os.path.join(repodir, LOCAL_MANIFEST_NAME)):
+      print('error: %s is not supported; put local manifests in `%s` instead' %
+            (LOCAL_MANIFEST_NAME, os.path.join(repodir, LOCAL_MANIFESTS_DIR_NAME)),
+            file=sys.stderr)
+      sys.exit(1)
+
+    if manifest_file is None:
+      manifest_file = os.path.join(repodir, MANIFEST_FILE_NAME)
+    local_manifests = os.path.abspath(os.path.join(repodir, LOCAL_MANIFESTS_DIR_NAME))
+    super(RepoClient, self).__init__(repodir, manifest_file, local_manifests)
+
+    # TODO: Completely separate manifest logic out of the client.
+    self.manifest = self
+
+
+class GitcClient(RepoClient, GitcManifest):
+  """Manages a GitC client checkout."""
+
+  def __init__(self, repodir, gitc_client_name):
+    """Initialize the GitcManifest object."""
+    self.gitc_client_name = gitc_client_name
+    self.gitc_client_dir = os.path.join(gitc_utils.get_gitc_manifest_dir(),
+                                        gitc_client_name)
+
+    super(GitcManifest, self).__init__(
+        repodir, os.path.join(self.gitc_client_dir, '.manifest'))
+    self.isGitcClient = True