Source reader should not hand back files with nil contents (#2003)

If a profile has a data files directory that looks like this:

```
files/platforms/one/data.json
files/platforms/two/data.json
files/platforms/three/data.json
```

... the source reader will return the directories in the list of files but with
nil contents. This causes an issue when Inspec::Profile tries to create a sha256
checksum of the profile contents only to try to cast nil to a string when
building the null-delimited profile contents string.

Files that are empty will have an empty string as its contents, so it's safe to
assume that file entries with nil contents are actually a directory and have no
affect on the profile's checksum. Therefore, this change will eliminate any file
entries in responses from the source readers where the contents are nil.

Signed-off-by: Adam Leff <adam@leff.co>

lib/source_readers/inspec.rb

@@ -54,21 +54,21 @@ module SourceReaders
       tests = @target.files.find_all do |path|
         path.start_with?('controls') && path.end_with?('.rb')
       end
-      Hash[tests.map { |x| [x, @target.read(x)] }]
+      Hash[tests.map { |x| [x, @target.read(x)] }.delete_if { |_file, contents| contents.nil? }]
     end
 
     def load_libs
       tests = @target.files.find_all do |path|
         path.start_with?('libraries') && path.end_with?('.rb')
       end
-      Hash[tests.map { |x| [x, @target.read(x)] }]
+      Hash[tests.map { |x| [x, @target.read(x)] }.delete_if { |_file, contents| contents.nil? }]
     end
 
     def load_data_files
       files = @target.files.find_all do |path|
         path.start_with?('files' + File::SEPARATOR)
       end
-      Hash[files.map { |x| [x, @target.read(x)] }]
+      Hash[files.map { |x| [x, @target.read(x)] }.delete_if { |_file, contents| contents.nil? }]
     end
   end
 end

test/unit/dsl/other_keywords_test.rb

@@ -46,7 +46,7 @@ describe 'inspec keyword' do
     end
 
     it 'lists all profile files when calling #files' do
-      load_in_profile('inspec.profile.files').must_equal %w{items.conf}
+      load_in_profile('inspec.profile.files').must_equal %w{a_sub_dir/sub_items.conf items.conf}
     end
   end
 

test/unit/file_provider_test.rb

@@ -86,7 +86,8 @@ describe Inspec::ZipProvider do
 
     it 'must contain all files' do
       subject.files.sort.must_equal %w{inspec.yml libraries libraries/testlib.rb
-        controls controls/filesystem_spec.rb files files/items.conf}.sort
+        controls controls/filesystem_spec.rb files files/a_sub_dir
+        files/a_sub_dir/sub_items.conf files/items.conf}.sort
     end
 
     it 'must not read if the file isnt included' do
@@ -108,7 +109,8 @@ describe Inspec::ZipProvider do
 
     it 'must contain all files' do
       subject.files.sort.must_equal %w{inspec.yml libraries libraries/testlib.rb
-        controls controls/filesystem_spec.rb files files/items.conf}.sort
+        controls controls/filesystem_spec.rb files files/a_sub_dir
+        files/a_sub_dir/sub_items.conf files/items.conf}.sort
     end
 
     it 'must not read if the file isnt included' do
@@ -129,7 +131,8 @@ describe Inspec::TarProvider do
 
     it 'must contain all files' do
       subject.files.sort.must_equal %w{inspec.yml libraries libraries/testlib.rb
-        controls controls/filesystem_spec.rb files files/items.conf}.sort
+        controls controls/filesystem_spec.rb files files/a_sub_dir
+        files/a_sub_dir/sub_items.conf files/items.conf}.sort
     end
 
     it 'must not read if the file isnt included' do

test/unit/mock/profiles/complete-profile/files/a_sub_dir/sub_items.conf

@@ -0,0 +1,2 @@
+[section]
+key = value

test/unit/profiles/profile_test.rb

@@ -70,7 +70,7 @@ describe Inspec::Profile do
     end
 
     it 'works on a complete profile' do
-      MockLoader.load_profile('complete-profile').sha256.must_equal 'b3dc0ec4603499ca9613e34da4a9476266875b8361b16be9284b39d1beacddd3'
+      MockLoader.load_profile('complete-profile').sha256.must_equal '5a129bd0a06f3d27589871a8dc8c65361d3730e802b926755191b610b7f99d3a'
     end
   end
 

test/unit/source_readers/inspec_test.rb

@@ -36,8 +36,9 @@ describe SourceReaders::InspecReader do
     end
 
     it 'retrieves all extra files' do
-      _(res.data_files.keys).must_equal %w{files/items.conf}
-      _(res.data_files.values[0]).must_equal "one\ntwo\nthree\n"
+      _(res.data_files.keys).must_equal %w{files/a_sub_dir/sub_items.conf files/items.conf}
+      _(res.data_files['files/items.conf']).must_equal "one\ntwo\nthree\n"
+      _(res.data_files['files/a_sub_dir/sub_items.conf']).must_equal "[section]\nkey = value\n"
     end
   end