[CHEF-5162] Support DelayedEvaluator for remote_file's source attribute

This commit adds the ability to pass a single DelayedEvaluator to the
source attribute of the remote_file resource.  If more than one
DelayedEvalutor is passed, an error will be raised.

The source attribute now accepts:

- A single string argument,
- Multiple string arguments
- A single array argument
- A single delayed evaluator argument

Technically, it also accepts

- An array of arrays

but this case is not tested.

2 files changed, 49 insertions, 6 deletions

diff --git a/lib/chef/resource/remote_file.rb b/lib/chef/resource/remote_file.rb
index 24d2562a9b..a10a0996a6 100644
--- a/lib/chef/resource/remote_file.rb
+++ b/lib/chef/resource/remote_file.rb
@@ -41,12 +41,24 @@ class Chef
       end
 
       def source(*args)
-        if not args.empty?
-          args = Array(args).flatten
-          validate_source(args)
-          @source = args
-        elsif self.instance_variable_defined?(:@source) == true
-          @source
+        arg = if args.empty?
+                nil
+              elsif args[0].is_a?(Chef::DelayedEvaluator) && args.count == 1
+                args[0]
+              elsif args.any? {|a| a.is_a?(Chef::DelayedEvaluator)} && args.count > 1
+                raise Exceptions::InvalidRemoteFileURI, "Only 1 DelayedEvaluator is allowed"
+              else
+                Array(args).flatten
+              end
+        ret = set_or_return(:source,
+                            arg,
+                            { :callbacks => {
+                                :validate_source => method(:validate_source)
+                              }})
+        if ret.is_a? String
+          Array(ret)
+        else
+          ret
         end
       end
 
@@ -107,6 +119,7 @@ class Chef
       private
 
       def validate_source(source)
+        source = Array(source).flatten
         raise ArgumentError, "#{resource_name} has an empty source" if source.empty?
         source.each do |src|
           unless absolute_uri?(src)
@@ -114,6 +127,7 @@ class Chef
               "#{src.inspect} is not a valid `source` parameter for #{resource_name}. `source` must be an absolute URI or an array of URIs."
           end
         end
+        true
       end
 
       def absolute_uri?(source)
diff --git a/spec/unit/resource/remote_file_spec.rb b/spec/unit/resource/remote_file_spec.rb
index 643bc8ba21..8f1633119d 100644
--- a/spec/unit/resource/remote_file_spec.rb
+++ b/spec/unit/resource/remote_file_spec.rb
@@ -50,20 +50,49 @@ describe Chef::Resource::RemoteFile do
       @resource.source.should eql([ "http://opscode.com/" ])
     end
 
+    it "should accept a delayed evalutator (string) for the remote file source" do
+      @resource.source Chef::DelayedEvaluator.new {"http://opscode.com/"}
+      @resource.source.should eql([ "http://opscode.com/" ])
+    end
+
     it "should accept an array of URIs for the remote file source" do
       @resource.source([ "http://opscode.com/", "http://puppetlabs.com/" ])
       @resource.source.should eql([ "http://opscode.com/", "http://puppetlabs.com/" ])
     end
 
+    it "should accept a delated evaluator (array) for the remote file source" do
+      @resource.source Chef::DelayedEvaluator.new { [ "http://opscode.com/", "http://puppetlabs.com/" ] }
+      @resource.source.should eql([ "http://opscode.com/", "http://puppetlabs.com/" ])
+    end
+
     it "should accept an multiple URIs as arguments for the remote file source" do
       @resource.source("http://opscode.com/", "http://puppetlabs.com/")
       @resource.source.should eql([ "http://opscode.com/", "http://puppetlabs.com/" ])
     end
 
+    it "should only accept a single argument if a delayed evalutor is used" do
+      lambda {
+        @resource.source("http://opscode.com/", Chef::DelayedEvaluator.new {"http://opscode.com/"})
+      }.should raise_error(Chef::Exceptions::InvalidRemoteFileURI)
+    end
+
+    it "should only accept a single array item if a delayed evalutor is used" do
+      lambda {
+        @resource.source(["http://opscode.com/", Chef::DelayedEvaluator.new {"http://opscode.com/"}])
+      }.should raise_error(Chef::Exceptions::InvalidRemoteFileURI)
+    end
+
     it "does not accept a non-URI as the source" do
       lambda { @resource.source("not-a-uri") }.should raise_error(Chef::Exceptions::InvalidRemoteFileURI)
     end
 
+    it "does not accept a non-URI as the source when read from a delayed evaluator" do
+      lambda {
+        @resource.source(Chef::DelayedEvaluator.new {"not-a-uri"})
+        @resource.source
+      }.should raise_error(Chef::Exceptions::InvalidRemoteFileURI)
+    end
+
     it "should raise an exception when source is an empty array" do
       lambda { @resource.source([]) }.should raise_error(ArgumentError)
     end