Merge branch 'dz-straight-diffs' into 'master'

Straight diffs support

Based on https://gitlab.com/gitlab-org/gitlab_git/merge_requests/41. 

All credentials to @ben.boeckel 

See merge request !125

CHANGELOG

+v 10.6.8
+  - Add straight parameter to Compare#initialize and straight option to Diff.between
+
 v 10.6.7
   - Commit.find returns nil and no longer throws an error on an empty repository

lib/gitlab_git/compare.rb

 module Gitlab
   module Git
     class Compare
-      attr_reader :head, :base
-      def initialize(repository, base, head)
+      attr_reader :head, :base, :straight
+      def initialize(repository, base, head, straight = false)
         @repository = repository
+        @straight = straight
         unless base && head
           @commits = []
@@ -34,6 +35,7 @@ module Gitlab
         end
         paths = options.delete(:paths) || []
+        options[:straight] = @straight
         Gitlab::Git::Diff.between(@repository, @head.id, @base.id, options, *paths)
       end
     end

lib/gitlab_git/diff.rb

@@ -21,13 +21,22 @@ module Gitlab
       class << self
         def between(repo, head, base, options = {}, *paths)
-          # Only show what is new in the source branch compared to the target branch, not the other way around.
-          # The linex below with merge_base is equivalent to diff with three dots (git diff branch1...branch2)
-          # From the git documentation: "git diff A...B" is equivalent to "git diff $(git-merge-base A B) B"
-          common_commit = repo.merge_base_commit(head, base)
+          straight = options.delete(:straight) || false
+
+          common_commit = if straight
+                            base
+                          else
+                            # Only show what is new in the source branch
+                            # compared to the target branch, not the other way
+                            # around. The linex below with merge_base is
+                            # equivalent to diff with three dots (git diff
+                            # branch1...branch2) From the git documentation:
+                            # "git diff A...B" is equivalent to "git diff
+                            # $(git-merge-base A B) B"
+                            repo.merge_base_commit(head, base)
+                          end
           options ||= {}
-          break_rewrites = options[:break_rewrites]
           actual_options = filter_diff_options(options)
           repo.diff(common_commit, head, actual_options, *paths)
         end

spec/compare_spec.rb

@@ -2,7 +2,8 @@ require "spec_helper"
 describe Gitlab::Git::Compare do
   let(:repository) { Gitlab::Git::Repository.new(TEST_REPO_PATH) }
-  let(:compare) { Gitlab::Git::Compare.new(repository, SeedRepo::BigCommit::ID, SeedRepo::Commit::ID) }
+  let(:compare) { Gitlab::Git::Compare.new(repository, SeedRepo::BigCommit::ID, SeedRepo::Commit::ID, false) }
+  let(:compare_straight) { Gitlab::Git::Compare.new(repository, SeedRepo::BigCommit::ID, SeedRepo::Commit::ID, true) }
   describe :commits do
     subject do
@@ -12,6 +13,7 @@ describe Gitlab::Git::Compare do
     it 'has 8 elements' do
       expect(subject.size).to eq(8)
     end
+
     it { is_expected.to include(SeedRepo::Commit::PARENT_ID) }
     it { is_expected.not_to include(SeedRepo::BigCommit::PARENT_ID) }
@@ -48,6 +50,7 @@ describe Gitlab::Git::Compare do
     it 'has 10 elements' do
       expect(subject.size).to eq(10)
     end
+
     it { is_expected.to include('files/ruby/popen.rb') }
     it { is_expected.not_to include('LICENSE') }
@@ -77,4 +80,30 @@ describe Gitlab::Git::Compare do
       it { is_expected.to eq(true) }
     end
   end
+
+  describe :commits_straight do
+    subject do
+      compare_straight.commits.map(&:id)
+    end
+
+    it 'has 8 elements' do
+      expect(subject.size).to eq(8)
+    end
+
+    it { is_expected.to include(SeedRepo::Commit::PARENT_ID) }
+    it { is_expected.not_to include(SeedRepo::BigCommit::PARENT_ID) }
+  end
+
+  describe :diffs_straight do
+    subject do
+      compare_straight.diffs.map(&:new_path)
+    end
+
+    it 'has 10 elements' do
+      expect(subject.size).to eq(10)
+    end
+
+    it { is_expected.to include('files/ruby/popen.rb') }
+    it { is_expected.not_to include('LICENSE') }
+  end
 end

spec/diff_spec.rb

@@ -94,6 +94,26 @@ EOT
     end
   end
+  describe 'straight diffs' do
+    let(:options) { { :straight => true } }
+    let(:diffs) { Gitlab::Git::Diff.between(repository, 'feature', 'master', options) }
+    subject { diffs }
+
+    describe '#size' do
+      subject { super().size }
+
+      it { is_expected.to eq(24) }
+    end
+
+    context :diff do
+      subject { diffs.first }
+
+      it { should be_kind_of Gitlab::Git::Diff }
+      its(:new_path) { should == '.DS_Store' }
+      its(:diff) { should include 'Binary files /dev/null and b/.DS_Store differ' }
+    end
+  end
+
   describe :between do
     let(:diffs) { Gitlab::Git::Diff.between(repository, 'feature', 'master') }
     subject { diffs }
@@ -102,6 +122,7 @@ EOT
     describe '#size' do
       subject { super().size }
+
       it { is_expected.to eq(1) }
     end
@@ -112,11 +133,13 @@ EOT
       describe '#new_path' do
         subject { super().new_path }
+
         it { is_expected.to eq('files/ruby/feature.rb') }
       end
       describe '#diff' do
         subject { super().diff }
+
         it { is_expected.to include '+class Feature' }
       end
     end