Creating a singleton per arguments passed to git_version

Author: agross

GitVersionExe/GemAssets/lib/git_version.rb

@@ -2,6 +2,11 @@
 
 module GitVersion
   def git_version(args = nil)
-    Parser.new(args)
+    parsers.fetch(args) { |a| parsers[a] = Parser.new(a) }
+  end
+
+  private
+  def parsers
+    @parsers ||= {}
   end
 end

GitVersionExe/GemAssets/spec/lib/git_version_spec.rb

@@ -6,4 +6,30 @@
   it 'should create a ' + GitVersion::Parser.to_s do
     expect(git_version).to be_an_instance_of(GitVersion::Parser)
   end
+
+  it 'should create a singleton ' + GitVersion::Parser.to_s do
+    expect(git_version).to equal(git_version)
+  end
+
+  describe 'passing arguments' do
+    it 'should yield the same instance per argument' do
+      expect(git_version('foo')).to equal(git_version('foo'))
+    end
+
+    it 'should yield different instances for different arguments' do
+      expect(git_version('foo')).not_to equal_no_diff(git_version('bar'))
+    end
+
+    def equal_no_diff(expected)
+      expected = equal(expected)
+
+      # Turn off diffing for this matcher as it calls GitVersion::Parser#to_ary which will fail because GitVersion.exe
+      # cannot be found.
+      def expected.diffable?
+        false
+      end
+
+      expected
+    end
+  end
 end