lib/r10k/feature.rb in r10k-1.5.1 vs lib/r10k/feature.rb in r10k-2.0.0

@@ -1,9 +1,13 @@
+require 'r10k/logging'
+
 module R10K
   # Detect whether a given feature is present or absent
   class Feature
 
+    include R10K::Logging
+
     # @attribute [r] name
     #   @return [Symbol] The name of this feature
     attr_reader :name
 
     # @param name [Symbol] The name of this feature
@@ -13,23 +17,40 @@
     # @option opts [String, Array<String>] :libraries One or more libraries to
     #   require to make sure this feature is present.
     def initialize(name, opts = {}, &block)
       @name      = name
       @libraries = Array(opts.delete(:libraries))
-      @block     = block || lambda { true }
+      @block     = block
     end
 
     # @return [true, false] Is this feature available?
     def available?
-      @libraries.all? { |lib| library_available?(lib) } && !!@block.call
+      logger.debug1 { "Testing to see if feature #{@name} is available." }
+      rv = @libraries.all? { |lib| library_available?(lib) } && proc_available?
+      msg = rv ? "is" : "is not"
+      logger.debug1 { "Feature #{@name} #{msg} available." }
+      rv
     end
 
     private
 
     def library_available?(lib)
+      logger.debug2 { "Attempting to load library '#{lib}' for feature #{@name}" }
       require lib
       true
-    rescue ScriptError
+    rescue ScriptError => e
+      logger.debug2 { "Error while loading library #{lib} for feature #{@name}: #{e.message}" }
       false
+    end
+
+    def proc_available?
+      if @block
+        logger.debug2 { "Evaluating proc #{@block.inspect} to test for feature #{@name}" }
+        output = @block.call
+        logger.debug2 { "Proc #{@block.inspect} for feature #{@name} returned #{output.inspect}" }
+        !!output
+      else
+        true
+      end
     end
   end
 end