Adding []/[]= support to Scope

The interface to scope is much clearer this way anyway,
but this is needed to integrate Puppet with Hiera[1].
It just provides hash-like behavior to Scope, which Hiera
and others can now easily rely on.

I also went through all of the code that used Scope#lookupvar
and Scope#setvar and changed it if possible, and at the same
time cleaned up a lot of tests that were unnecessarily stubbing
(and thus making it difficult to tell if I had actually broken
anything).

1 - https://github.com/ripienaar/hiera

Signed-off-by: Luke Kanies <luke@puppetlabs.com>
Reviewed-by: Nick Lewis <nick@puppetlabs.com>

8 files changed, 56 insertions, 45 deletions

diff --git a/lib/puppet/parser/ast/leaf.rb b/lib/puppet/parser/ast/leaf.rb
index c8ebc9483..64a197492 100644
--- a/lib/puppet/parser/ast/leaf.rb
+++ b/lib/puppet/parser/ast/leaf.rb
@@ -124,7 +124,7 @@ class Puppet::Parser::AST
     # not include syntactical constructs, like '$' and '{}').
     def evaluate(scope)
       parsewrap do
-        if (var = scope.lookupvar(@value, :file => file, :line => line)) == :undefined
+        if (var = scope[@value, {:file => file, :line => line}]) == :undefined
           var = :undef
         end
         var
@@ -141,7 +141,7 @@ class Puppet::Parser::AST
 
     def evaluate_container(scope)
       container = variable.respond_to?(:evaluate) ? variable.safeevaluate(scope) : variable
-      (container.is_a?(Hash) or container.is_a?(Array)) ? container : scope.lookupvar(container, :file => file, :line => line)
+      (container.is_a?(Hash) or container.is_a?(Array)) ? container : scope[container, {:file => file, :line => line}]
     end
 
     def evaluate_key(scope)
diff --git a/lib/puppet/parser/compiler.rb b/lib/puppet/parser/compiler.rb
index c1daade4c..f43a31285 100644
--- a/lib/puppet/parser/compiler.rb
+++ b/lib/puppet/parser/compiler.rb
@@ -450,7 +450,7 @@ class Puppet::Parser::Compiler
   # Set the node's parameters into the top-scope as variables.
   def set_node_parameters
     node.parameters.each do |param, value|
-      @topscope.setvar(param, value)
+      @topscope[param] = value
     end
 
     # These might be nil.
@@ -473,7 +473,7 @@ class Puppet::Parser::Compiler
 
     Puppet.settings.each do |name, setting|
       next if name.to_s == "name"
-      scope.setvar name.to_s, environment[name]
+      scope[name.to_s] = environment[name]
     end
   end
 
diff --git a/lib/puppet/parser/functions/extlookup.rb b/lib/puppet/parser/functions/extlookup.rb
index 5fbf26cec..9ffca59a7 100644
--- a/lib/puppet/parser/functions/extlookup.rb
+++ b/lib/puppet/parser/functions/extlookup.rb
@@ -91,9 +91,9 @@ This is for back compatibility to interpolate variables with %. % interpolation
 
   raise Puppet::ParseError, ("extlookup(): wrong number of arguments (#{args.length}; must be <= 3)") if args.length > 3
 
-  extlookup_datadir = undef_as('',lookupvar('::extlookup_datadir'))
+  extlookup_datadir = undef_as('',self['::extlookup_datadir'])
 
-  extlookup_precedence = undef_as([],lookupvar('::extlookup_precedence')).collect { |var| var.gsub(/%\{(.+?)\}/) { lookupvar("::#{$1}") } }
+  extlookup_precedence = undef_as([],self['::extlookup_precedence']).collect { |var| var.gsub(/%\{(.+?)\}/) { self["::#{$1}"] } }
 
   datafiles = Array.new
 
@@ -121,9 +121,9 @@ This is for back compatibility to interpolate variables with %. % interpolation
           if result[0].length == 2
             val = result[0][1].to_s
 
-            # parse %{}'s in the CSV into local variables using lookupvar()
+            # parse %{}'s in the CSV into local variables using the current scope
             while val =~ /%\{(.+?)\}/
-              val.gsub!(/%\{#{$1}\}/, lookupvar($1))
+              val.gsub!(/%\{#{$1}\}/, self[$1])
             end
 
             desired = val
@@ -134,9 +134,9 @@ This is for back compatibility to interpolate variables with %. % interpolation
             # Individual cells in a CSV result are a weird data type and throws
             # puppets yaml parsing, so just map it all to plain old strings
             desired = cells.map do |c|
-              # parse %{}'s in the CSV into local variables using lookupvar()
+              # parse %{}'s in the CSV into local variables using the current scope
               while c =~ /%\{(.+?)\}/
-                c.gsub!(/%\{#{$1}\}/, lookupvar($1))
+                c.gsub!(/%\{#{$1}\}/, self[$1])
               end
 
               c.to_s
diff --git a/lib/puppet/parser/functions/fqdn_rand.rb b/lib/puppet/parser/functions/fqdn_rand.rb
index 93ab98bcd..668802e73 100644
--- a/lib/puppet/parser/functions/fqdn_rand.rb
+++ b/lib/puppet/parser/functions/fqdn_rand.rb
@@ -7,6 +7,6 @@ Puppet::Parser::Functions::newfunction(:fqdn_rand, :type => :rvalue, :doc =>
       $random_number_seed = fqdn_rand(30,30)") do |args|
     require 'digest/md5'
     max = args.shift
-    srand(Digest::MD5.hexdigest([lookupvar('::fqdn'),args].join(':')).hex)
+    srand(Digest::MD5.hexdigest([self['::fqdn'],args].join(':')).hex)
     rand(max).to_s
 end
diff --git a/lib/puppet/parser/resource.rb b/lib/puppet/parser/resource.rb
index 3bb5f8601..305ba81e8 100644
--- a/lib/puppet/parser/resource.rb
+++ b/lib/puppet/parser/resource.rb
@@ -258,7 +258,7 @@ class Puppet::Parser::Resource < Puppet::Resource
 
   def add_backward_compatible_relationship_param(name)
     # Skip metaparams for which we get no value.
-    return unless val = scope.lookupvar(name.to_s) and val != :undefined
+    return unless val = scope[name.to_s] and val != :undefined
 
     # The default case: just set the value
     set_parameter(name, val) and return unless @parameters[name]
diff --git a/lib/puppet/parser/scope.rb b/lib/puppet/parser/scope.rb
index ed67cd141..67dcb1cb0 100644
--- a/lib/puppet/parser/scope.rb
+++ b/lib/puppet/parser/scope.rb
@@ -48,6 +48,35 @@ class Puppet::Parser::Scope
     end
   end
 
+  def [](name, options = {})
+    table = ephemeral?(name) ? @ephemeral.last : @symtable
+    # If the variable is qualified, then find the specified scope and look the variable up there instead.
+    if name =~ /^(.*)::(.+)$/
+      begin
+        qualified_scope($1)[$2,options]
+      rescue RuntimeError => e
+        location = (options[:file] && options[:line]) ? " at #{options[:file]}:#{options[:line]}" : ''
+        warning "Could not look up qualified variable '#{name}'; #{e.message}#{location}"
+        :undefined
+      end
+    elsif ephemeral_include?(name) or table.include?(name)
+      # We can't use "if table[name]" here because the value might be false
+      if options[:dynamic] and self != compiler.topscope
+        location = (options[:file] && options[:line]) ? " at #{options[:file]}:#{options[:line]}" : ''
+        Puppet.deprecation_warning "Dynamic lookup of $#{name}#{location} is deprecated.  Support will be removed in Puppet 2.8.  Use a fully-qualified variable name (e.g., $classname::variable) or parameterized classes."
+      end
+      table[name]
+    elsif parent
+      parent[name,options.merge(:dynamic => (dynamic || options[:dynamic]))]
+    else
+      :undefined
+    end
+  end
+
+  def []=(var, value)
+    setvar(var, value)
+  end
+
   # A demeterific shortcut to the catalog.
   def catalog
     compiler.catalog
@@ -223,29 +252,9 @@ class Puppet::Parser::Scope
   private :qualified_scope
 
   # Look up a variable.  The simplest value search we do.
+  # This method is effectively deprecated - use self[] instead.
   def lookupvar(name, options = {})
-    table = ephemeral?(name) ? @ephemeral.last : @symtable
-    # If the variable is qualified, then find the specified scope and look the variable up there instead.
-    if name =~ /^(.*)::(.+)$/
-      begin
-        qualified_scope($1).lookupvar($2,options)
-      rescue RuntimeError => e
-        location = (options[:file] && options[:line]) ? " at #{options[:file]}:#{options[:line]}" : ''
-        warning "Could not look up qualified variable '#{name}'; #{e.message}#{location}"
-        :undefined
-      end
-    elsif ephemeral_include?(name) or table.include?(name)
-      # We can't use "if table[name]" here because the value might be false
-      if options[:dynamic] and self != compiler.topscope
-        location = (options[:file] && options[:line]) ? " at #{options[:file]}:#{options[:line]}" : ''
-        Puppet.deprecation_warning "Dynamic lookup of $#{name}#{location} is deprecated.  Support will be removed in Puppet 2.8.  Use a fully-qualified variable name (e.g., $classname::variable) or parameterized classes."
-      end
-      table[name]
-    elsif parent
-      parent.lookupvar(name,options.merge(:dynamic => (dynamic || options[:dynamic])))
-    else
-      :undefined
-    end
+    self[name, options]
   end
 
   # Return a hash containing our variables and their values, optionally (and
@@ -312,6 +321,8 @@ class Puppet::Parser::Scope
   # Set a variable in the current scope.  This will override settings
   # in scopes above, but will not allow variables in the current scope
   # to be reassigned.
+  #   It's preferred that you use self[]= instead of this; only use this
+  # when you need to set options.
   def setvar(name,value, options = {})
     table = options[:ephemeral] ? @ephemeral.last : @symtable
     if table.include?(name)
@@ -329,7 +340,7 @@ class Puppet::Parser::Scope
       table[name] = value
     else # append case
       # lookup the value in the scope if it exists and insert the var
-      table[name] = undef_as('',lookupvar(name))
+      table[name] = undef_as('',self[name])
       # concatenate if string, append if array, nothing for other types
       case value
       when Array
diff --git a/lib/puppet/parser/templatewrapper.rb b/lib/puppet/parser/templatewrapper.rb
index 27d75bf92..83d18cc3f 100644
--- a/lib/puppet/parser/templatewrapper.rb
+++ b/lib/puppet/parser/templatewrapper.rb
@@ -25,7 +25,7 @@ class Puppet::Parser::TemplateWrapper
 
   # Should return true if a variable is defined, false if it is not
   def has_variable?(name)
-    scope.lookupvar(name.to_s, :file => file, :line => script_line) != :undefined
+    scope[name.to_s, {:file => file, :line => script_line}] != :undefined
   end
 
   # Allow templates to access the defined classes
@@ -56,7 +56,7 @@ class Puppet::Parser::TemplateWrapper
   # the missing_method definition here until we declare the syntax finally
   # dead.
   def method_missing(name, *args)
-    value = scope.lookupvar(name.to_s,:file => file,:line => script_line)
+    value = scope[name.to_s, {:file => file,:line => script_line}]
     if value != :undefined
       return value
     else
diff --git a/lib/puppet/resource/type.rb b/lib/puppet/resource/type.rb
index f8d820b77..7b251e8c7 100644
--- a/lib/puppet/resource/type.rb
+++ b/lib/puppet/resource/type.rb
@@ -225,22 +225,22 @@ class Puppet::Resource::Type
       param = param.to_sym
       fail Puppet::ParseError, "#{resource.ref} does not accept attribute #{param}" unless valid_parameter?(param)
 
-      exceptwrap { scope.setvar(param.to_s, value) }
+      exceptwrap { scope[param.to_s] = value }
 
       set[param] = true
     end
 
     if @type == :hostclass
-      scope.setvar("title", resource.title.to_s.downcase) unless set.include? :title
-      scope.setvar("name",  resource.name.to_s.downcase ) unless set.include? :name
+      scope["title"] = resource.title.to_s.downcase unless set.include? :title
+      scope["name"] =  resource.name.to_s.downcase  unless set.include? :name
     else
-      scope.setvar("title", resource.title              ) unless set.include? :title
-      scope.setvar("name",  resource.name               ) unless set.include? :name
+      scope["title"] = resource.title               unless set.include? :title
+      scope["name"] =  resource.name                unless set.include? :name
     end
-    scope.setvar("module_name", module_name) if module_name and ! set.include? :module_name
+    scope["module_name"] = module_name if module_name and ! set.include? :module_name
 
     if caller_name = scope.parent_module_name and ! set.include?(:caller_module_name)
-      scope.setvar("caller_module_name", caller_name)
+      scope["caller_module_name"] = caller_name
     end
     scope.class_set(self.name,scope) if hostclass? or node?
     # Verify that all required arguments are either present or
@@ -253,7 +253,7 @@ class Puppet::Resource::Type
       fail Puppet::ParseError, "Must pass #{param} to #{resource.ref}" unless default
 
       value = default.safeevaluate(scope)
-      scope.setvar(param.to_s, value)
+      scope[param.to_s] = value
 
       # Set it in the resource, too, so the value makes it to the client.
       resource[param] = value