[CHEF-3806] add attribute value debug

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/chef/node/attribute.rb b/lib/chef/node/attribute.rb
index e2bb8b9cf9..a417406721 100644
--- a/lib/chef/node/attribute.rb
+++ b/lib/chef/node/attribute.rb
@@ -209,6 +209,34 @@ class Chef
          @combined_default = nil
        end
 
+       # Debug what's going on with an attribute. +args+ is a path spec to the
+       # attribute you're interested in. For example, to debug where the value
+       # of `node[:network][:default_interface]` is coming from, use:
+       #   debug_value(:network, :default_interface).
+       # The return value is an Array of Arrays. The first element is
+       # `["set_unless_enabled?", Boolean]`, which describes whether the
+       # attribute collection is in "set_unless" mode. The rest of the Arrays
+       # are pairs of `["precedence_level", value]`, where precedence level is
+       # the component, such as role default, normal, etc. and value is the
+       # attribute value set at that precedence level. If there is no value at
+       # that precedence level, +value+ will be the symbol +:not_present+.
+       def debug_value(*args)
+         components = COMPONENTS.map do |component|
+           ivar = instance_variable_get(component)
+           value = args.inject(ivar) do |so_far, key|
+             if so_far == :not_present
+               :not_present
+             elsif so_far.has_key?(key)
+               so_far[key]
+             else
+               :not_present
+             end
+           end
+           [component.to_s.sub(/^@/,""), value]
+         end
+         [["set_unless_enabled?", @set_unless_present]] + components
+       end
+
        # Enables or disables `||=`-like attribute setting. See, e.g., Node#set_unless
        def set_unless_value_present=(setting)
          @set_unless_present = setting