Make improvements to GitCommitSha functionality.

- refactor GitCommitSha class according to suggestions by @justin808
- access GitCommitSha directly from pages_helper instead of going through controller
- display shorter version of the hash
- make the hash link to the corresponding commit on GitHub

Author: robwise

app/controllers/pages_controller.rb

@@ -1,7 +1,6 @@
 class PagesController < ApplicationController
   def index
     @comments = Comment.all
-    @git_commit_sha = GitCommitSha.current_sha
 
     # NOTE: The below notes apply if you want to set the value of the props in the controller, as
     # compared to he view. However, it's more convenient to use Jbuilder from the view. See

app/helpers/pages_helper.rb

@@ -1,2 +1,10 @@
 module PagesHelper
+  def git_commit_sha
+    GitCommitSha.current_sha
+  end
+
+  def git_commit_sha_short
+    full_sha = git_commit_sha
+    full_sha.slice(full_sha.size - 7, full_sha.size)
+  end
 end

app/models/git_commit_sha.rb

@@ -1,15 +1,14 @@
 class GitCommitSha
   def self.current_sha
-    return @commit_sha unless @commit_sha.blank?
-    @commit_sha = (retrieve_sha_from_env_var || retrieve_sha_from_git_folder)
+    @commit_sha ||= retrieve_sha_from_env_var.presence || retrieve_sha_from_git_folder
   end
 
   def self.current_sha=(sha)
     @commit_sha = sha
   end
 
   def self.reset_current_sha
-    self.current_sha = ""
+    self.current_sha = nil
   end
 
   def self.retrieve_sha_from_git_folder
@@ -18,6 +17,6 @@ def self.retrieve_sha_from_git_folder
 
   def self.retrieve_sha_from_env_var
     env_var = ENV["DEPLOYMENT_SHA"]
-    env_var.blank? ? false : env_var
+    env_var.blank? ? nil : env_var
   end
 end

app/views/pages/index.html.erb

@@ -1,8 +1,8 @@
 <h2>Using React + Redux + Rails Backend (using the react_on_rails gem)</h2>
-<p>current Git commit:
-  <span id="current-git-commit-sha">
-    <%= @git_commit_sha %>
-  </span>
+<p>Current Commit:
+  <%= link_to git_commit_sha_short,
+      "https://github.com/shakacode/react-webpack-rails-tutorial/commit/#{git_commit_sha}",
+      id: "git-commit-sha" %>
 </p>
 <ul>
   <li>

spec/features/pages_spec.rb

@@ -6,18 +6,20 @@
   after { ENV["DEPLOYMENT_SHA"] = old_sha }
   background { visit root_path }
   it "displays the current git commit" do
-    expect(page).to have_css("#current-git-commit-sha", text: sha)
+    expect(page).to have_css("#git-commit-sha", text: expected_text)
   end
 end
 
 feature "Git Commit SHA" do
   context "when env var is not set" do
     let(:sha) { "94d92356828a56db25fccff9d50f41c525eead5x" }
+    let(:expected_text) { "5eead5x" }
     before { GitCommitSha.current_sha = sha }
     it_behaves_like "Git Commit SHA"
   end
   context "when env var is set" do
     let(:sha) { "94d92356828a56db25fccff9d50f41c525eead5y" }
+    let(:expected_text) { "5eead5y" }
     before do
       ENV["DEPLOYMENT_SHA"] = sha
       GitCommitSha.reset_current_sha