subcmds: stop instantiating at import time

The current subcmds design has singletons in all_commands.  This isn't
exactly unusual, but the fact that our main & help subcommand will then
attach members to the classes before invoking them is.  This makes it
hard to keep track of what members a command has access to, and the two
code paths (main & help) attach different members depending on what APIs
they then invoke.

Lets pull this back a step by storing classes in all_commands and leave
the instantiation step to when they're used.  This doesn't fully clean
up the confusion, but gets us closer.

Change-Id: I6a768ff97fe541e6f3228358dba04ed66c4b070a
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/259154
Tested-by: Mike Frysinger <vapier@google.com>
Reviewed-by: David Pursehouse <dpursehouse@collab.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/subcmds/__init__.py b/subcmds/__init__.py
index a49e7bd3..c3de9d1e 100644
--- a/subcmds/__init__.py
+++ b/subcmds/__init__.py
@@ -16,6 +16,7 @@
 
 import os
 
+# A mapping of the subcommand name to the class that implements it.
 all_commands = {}
 
 my_dir = os.path.dirname(__file__)
@@ -37,7 +38,7 @@ for py in os.listdir(my_dir):
                      ['%s' % name])
     mod = getattr(mod, name)
     try:
-      cmd = getattr(mod, clsn)()
+      cmd = getattr(mod, clsn)
     except AttributeError:
       raise SyntaxError('%s/%s does not define class %s' % (
           __name__, py, clsn))