suppress cookbook self-dependencies and warnlcg/warn-cb-self-dep

cookbooks with self-deps:

name 'foo'
depends 'foo'

are useless and can waste cycles in the depsolver (particularly in
the non-solution case), and likely limit the possible choices of
depsolvers that we could pick at some point to replace gecode.

filtering out the self-dep here will prevent the chef server depsolver
from seeing the self-dep and needing to do the work to strip it.

also warn the user so that they can remove the self-dep.

in the future this will be a hard error.

foodcritic also has a rule about removing these.

1 files changed, 7 insertions, 3 deletions

diff --git a/lib/chef/cookbook/metadata.rb b/lib/chef/cookbook/metadata.rb
index 4f12275a82..01a98fda39 100644
--- a/lib/chef/cookbook/metadata.rb
+++ b/lib/chef/cookbook/metadata.rb
@@ -286,9 +286,13 @@ class Chef
       # === Returns
       # versions<Array>:: Returns the list of versions for the platform
       def depends(cookbook, *version_args)
-        version = new_args_format(:depends, cookbook, version_args)
-        constraint = validate_version_constraint(:depends, cookbook, version)
-        @dependencies[cookbook] = constraint.to_s
+        if cookbook == name
+          Chef::Log.warn "Ignoring self-dependency in cookbook #{name}, please remove it (in the future this will be fatal)."
+        else
+          version = new_args_format(:depends, cookbook, version_args)
+          constraint = validate_version_constraint(:depends, cookbook, version)
+          @dependencies[cookbook] = constraint.to_s
+        end
         @dependencies[cookbook]
       end