DRY up diff_for_path actions

1. Move render method to a concern, not a helper.
2. Let DiffHelper#diff_options automatically add the path option.
3. Move more instance var definitions to before filters.

1 files changed, 28 insertions, 40 deletions

diff --git a/app/controllers/projects/compare_controller.rb b/app/controllers/projects/compare_controller.rb
index 5e00d2d5aff..5f3ee71444d 100644
--- a/app/controllers/projects/compare_controller.rb
+++ b/app/controllers/projects/compare_controller.rb
@@ -1,60 +1,26 @@
 require 'addressable/uri'
 
 class Projects::CompareController < Projects::ApplicationController
+  include DiffForPath
   include DiffHelper
 
   # Authorize
   before_action :require_non_empty_project
   before_action :authorize_download_code!
-  before_action :assign_ref_vars, only: [:index, :show, :diff_for_path]
+  before_action :define_ref_vars, only: [:index, :show, :diff_for_path]
+  before_action :define_diff_vars, only: [:show, :diff_for_path]
   before_action :merge_request, only: [:index, :show]
 
   def index
   end
 
   def show
-    compare = CompareService.new.
-      execute(@project, @head_ref, @project, @start_ref)
-
-    if compare
-      @commits = Commit.decorate(compare.commits, @project)
-
-      @start_commit = @project.commit(@start_ref)
-      @commit = @project.commit(@head_ref)
-      @base_commit = @project.merge_base_commit(@start_ref, @head_ref)
-
-      @diffs = compare.diffs(diff_options)
-      @diff_refs = Gitlab::Diff::DiffRefs.new(
-        base_sha: @base_commit.try(:sha),
-        start_sha: @start_commit.try(:sha),
-        head_sha: @commit.try(:sha)
-      )
-
-      @diff_notes_disabled = true
-      @grouped_diff_notes = {}
-    end
   end
 
   def diff_for_path
-    compare = CompareService.new.
-      execute(@project, @head_ref, @project, @start_ref)
-
-    return render_404 unless compare
-
-    @start_commit = @project.commit(@start_ref)
-    @commit = @project.commit(@head_ref)
-    @base_commit = @project.merge_base_commit(@start_ref, @head_ref)
-    diffs = compare.diffs(diff_options.merge(paths: [params[:path]]))
-    diff_refs = Gitlab::Diff::DiffRefs.new(
-      base_sha: @base_commit.try(:sha),
-      start_sha: @start_commit.try(:sha),
-      head_sha: @commit.try(:sha)
-    )
-
-    @diff_notes_disabled = true
-    @grouped_diff_notes = {}
+    return render_404 unless @compare
 
-    render_diff_for_path(diffs, diff_refs, @project)
+    render_diff_for_path(@diffs, @diff_refs, @project)
   end
 
   def create
@@ -64,11 +30,33 @@ class Projects::CompareController < Projects::ApplicationController
 
   private
 
-  def assign_ref_vars
+  def define_ref_vars
     @start_ref = Addressable::URI.unescape(params[:from])
     @ref = @head_ref = Addressable::URI.unescape(params[:to])
   end
 
+  def define_diff_vars
+    @compare = CompareService.new.execute(@project, @head_ref, @project, @start_ref)
+
+    if @compare
+      @commits = Commit.decorate(@compare.commits, @project)
+
+      @start_commit = @project.commit(@start_ref)
+      @commit = @project.commit(@head_ref)
+      @base_commit = @project.merge_base_commit(@start_ref, @head_ref)
+
+      @diffs = @compare.diffs(diff_options)
+      @diff_refs = Gitlab::Diff::DiffRefs.new(
+        base_sha: @base_commit.try(:sha),
+        start_sha: @start_commit.try(:sha),
+        head_sha: @commit.try(:sha)
+      )
+
+      @diff_notes_disabled = true
+      @grouped_diff_notes = {}
+    end
+  end
+
   def merge_request
     @merge_request ||= @project.merge_requests.opened.
       find_by(source_project: @project, source_branch: @head_ref, target_branch: @start_ref)