implement feedback from review

Signed-off-by: kzwin <kz@example.org>

2 files changed, 29 insertions, 4 deletions

diff --git a/lib/chef/provider/git.rb b/lib/chef/provider/git.rb
index 29714ecf43..5b16e98427 100644
--- a/lib/chef/provider/git.rb
+++ b/lib/chef/provider/git.rb
@@ -105,11 +105,15 @@ class Chef
         end
       end
 
+      def git_has_single_branch_option?
+        @git_has_single_branch_option ||= !git_gem_version.nil? && git_gem_version >=  Gem::Version.new("1.7.10")
+      end
+
       def git_gem_version
+        defined?(@git_gem_version) and return @git_gem_version
         output = git("--version").stdout
         match = GIT_VERSION_PATTERN.match(output)
-        raise ArgumentError, "unparsable git version number #{output}" unless match
-        @git_gem_version ||= Gem::Version.new(match[1])
+        @git_gem_version ||= match ? Gem::Version.new(match[1]) : nil
       end
 
       def existing_git_clone?
@@ -147,7 +151,7 @@ class Chef
           clone_cmd = ["clone"]
           clone_cmd << "-o #{remote}" unless remote == "origin"
           clone_cmd << "--depth #{new_resource.depth}" if new_resource.depth
-          clone_cmd << "--no-single-branch" if new_resource.depth && git_gem_version >= Gem::Version.new("1.7.10")
+          clone_cmd << "--no-single-branch" if new_resource.depth && git_has_single_branch_option?
           clone_cmd << "\"#{new_resource.repository}\""
           clone_cmd << "\"#{cwd}\""
 
diff --git a/spec/unit/provider/git_spec.rb b/spec/unit/provider/git_spec.rb
index 1b52b05a91..cacee0baaa 100644
--- a/spec/unit/provider/git_spec.rb
+++ b/spec/unit/provider/git_spec.rb
@@ -109,7 +109,28 @@ describe Chef::Provider::Git do
       expect(@provider).to receive(:shell_out!)
         .with("git --version", log_tag: "git[web2.0 app]")
         .and_return(double("ShellOut result", stdout: "git version home-grown-git-99"))
-      expect { @provider.git_gem_version }.to raise_error(ArgumentError, /unparsable git version/)
+      expect(@provider.git_gem_version).to be_nil
+    end
+
+    it "determines single branch option when it fails to parse git version" do
+      expect(@provider).to receive(:shell_out!)
+        .with("git --version", log_tag: "git[web2.0 app]")
+        .and_return(double("ShellOut result", stdout: "git version home-grown-git-99"))
+      expect(@provider.git_has_single_branch_option?).to be false
+    end
+
+    it "determines single branch option as true when it parses git version and version is large" do
+      expect(@provider).to receive(:shell_out!)
+        .with("git --version", log_tag: "git[web2.0 app]")
+        .and_return(double("ShellOut result", stdout: "git version 1.8.0"))
+      expect(@provider.git_has_single_branch_option?).to be true
+    end
+
+    it "determines single branch option as false when it parses git version and version is small" do
+      expect(@provider).to receive(:shell_out!)
+        .with("git --version", log_tag: "git[web2.0 app]")
+        .and_return(double("ShellOut result", stdout: "git version 1.7.4"))
+      expect(@provider.git_has_single_branch_option?).to be false
     end
 
     it "is compatible with git in travis" do