add a test for creating subclassed instances

spec/unit/puppet/provider/ini_setting/inheritance_spec.rb

@@ -0,0 +1,61 @@
+require 'spec_helper'
+
+# This is a reduced version of ruby_spec.rb just to ensure we can subclass as
+# documented
+$: << 'spec/fixtures/modules/inherit_ini_setting/lib'
+provider_class = Puppet::Type.type(:inherit_ini_setting).provider(:ini_setting)
+describe provider_class do
+  include PuppetlabsSpec::Files
+
+  let(:tmpfile) { tmpfilename('inherit_ini_setting_test') }
+
+  def validate_file(expected_content,tmpfile = tmpfile)
+    File.read(tmpfile).should == expected_content
+  end
+
+
+  before :each do
+    File.open(tmpfile, 'w') do |fh|
+      fh.write(orig_content)
+    end
+  end
+
+  context 'when calling instances' do
+    let(:orig_content) { '' }
+
+    it 'should parse nothing when the file is empty' do
+      provider_class.stubs(:file_path).returns(tmpfile)
+      provider_class.instances.should == []
+    end
+
+    context 'when the file has contents' do
+      let(:orig_content) {
+        <<-EOS
+# A comment
+red = blue
+green = purple
+        EOS
+      }
+
+      it 'should parse the results' do
+        provider_class.stubs(:file_path).returns(tmpfile)
+        provider_class.instances.size.should == 2
+      end
+    end
+  end
+
+  context 'when ensuring that a setting is present' do
+    let(:orig_content) { '' }
+
+    it 'should add a value to the file' do
+      provider_class.stubs(:file_path).returns(tmpfile)
+      resource = Puppet::Type::Inherit_ini_setting.new(
+        :setting => 'set_this',
+        :value   => 'to_that',
+      )
+      provider = described_class.new(resource)
+      provider.create
+      validate_file("set_this=to_that\n")
+    end
+  end
+end