Fix undefined method error in facts

lib/facter/pip_version.rb

@@ -1,9 +1,26 @@
 # Make pip version available as a fact
 
+def get_pip_version(executable)
+  if Facter::Util::Resolution.which(executable) # rubocop:disable Style/GuardClause
+    results = Facter::Util::Resolution.exec("#{executable} --version 2>&1").match(%r{^pip (\d+\.\d+\.?\d*).*$})
+    results[1] if results
+  end
+end
+
 Facter.add('pip_version') do
   setcode do
-    if Facter::Util::Resolution.which('pip')
-      Facter::Util::Resolution.exec('pip --version 2>&1').match(%r{^pip (\d+\.\d+\.?\d*).*$})[1]
-    end
+    get_pip_version 'pip'
+  end
+end
+
+Facter.add('pip2_version') do
+  setcode do
+    get_pip_version 'pip2'
+  end
+end
+
+Facter.add('pip3_version') do
+  setcode do
+    get_pip_version 'pip3'
   end
 end

lib/facter/virtualenv_version.rb

@@ -3,7 +3,8 @@
 Facter.add('virtualenv_version') do
   setcode do
     if Facter::Util::Resolution.which('virtualenv')
-      Facter::Util::Resolution.exec('virtualenv --version 2>&1').match(%r{(\d+\.\d+\.?\d*).*$})[1]
+      results = Facter::Util::Resolution.exec('virtualenv --version 2>&1').match(%r{(\d+\.\d+\.?\d*).*$})
+      results[1] if results
     end
   end
 end

spec/unit/facter/pip_version_spec.rb

@@ -11,6 +11,18 @@
 EOS
   end
 
+  let(:pip2_version_output) do
+    <<-EOS
+pip 9.0.1 from /usr/lib/python2.7/dist-packages/pip (python 2.7)
+EOS
+  end
+
+  let(:pip3_version_output) do
+    <<-EOS
+pip 18.1 from /usr/lib/python3/dist-packages/pip (python 3.7)
+EOS
+  end
+
   describe 'pip_version' do
     context 'returns pip version when pip present' do
       it do
@@ -29,4 +41,42 @@
       end
     end
   end
+
+  describe 'pip2_version' do
+    context 'returns pip2 version when pip2 present' do
+      it do
+        Facter::Util::Resolution.stubs(:exec)
+        Facter::Util::Resolution.expects(:which).with('pip2').returns(true)
+        Facter::Util::Resolution.expects(:exec).with('pip2 --version 2>&1').returns(pip2_version_output)
+        expect(Facter.value(:pip2_version)).to eq('9.0.1')
+      end
+    end
+
+    context 'returns nil when pip2 not present' do
+      it do
+        Facter::Util::Resolution.stubs(:exec)
+        Facter::Util::Resolution.expects(:which).with('pip2').returns(false)
+        expect(Facter.value(:pip2_version)).to eq(nil)
+      end
+    end
+  end
+
+  describe 'pip3_version' do
+    context 'returns pip3 version when pip3 present' do
+      it do
+        Facter::Util::Resolution.stubs(:exec)
+        Facter::Util::Resolution.expects(:which).with('pip3').returns(true)
+        Facter::Util::Resolution.expects(:exec).with('pip3 --version 2>&1').returns(pip3_version_output)
+        expect(Facter.value(:pip3_version)).to eq('18.1')
+      end
+    end
+
+    context 'returns nil when pip3 not present' do
+      it do
+        Facter::Util::Resolution.stubs(:exec)
+        Facter::Util::Resolution.expects(:which).with('pip3').returns(false)
+        expect(Facter.value(:pip3_version)).to eq(nil)
+      end
+    end
+  end
 end