Remove the `ForkedProjectLink` model

This removes the `ForkedProjectLink` model that has been replaced by
the `ForkNetworkMember` and `ForkNetwork` combination. All existing
relations have been adjusted to use these new models.

The `forked_project_link` table has been dropped.

The "Forks" count on the admin dashboard has been updated to count all
`ForkNetworkMember` rows and deduct the number of `ForkNetwork`
rows. This is because now the "root-project" of a fork network also
has a `ForkNetworkMember` row. This count could become inaccurate when
the root of a fork network is deleted.

4 files changed, 18 insertions, 10 deletions

diff --git a/spec/features/merge_request/user_edits_mr_spec.rb b/spec/features/merge_request/user_edits_mr_spec.rb
index 8c9e782aa76..3152707136c 100644
--- a/spec/features/merge_request/user_edits_mr_spec.rb
+++ b/spec/features/merge_request/user_edits_mr_spec.rb
@@ -1,11 +1,13 @@
 require 'rails_helper'
 
 describe 'Merge request > User edits MR' do
+  include ProjectForksHelper
+
   it_behaves_like 'an editable merge request'
 
   context 'for a forked project' do
     it_behaves_like 'an editable merge request' do
-      let(:source_project) { create(:project, :repository, forked_from_project: target_project) }
+      let(:source_project) { fork_project(target_project, nil, repository: true) }
     end
   end
 end
diff --git a/spec/features/merge_request/user_sees_mr_from_deleted_forked_project_spec.rb b/spec/features/merge_request/user_sees_mr_from_deleted_forked_project_spec.rb
index 029b66b5e8e..fc4a188d4a7 100644
--- a/spec/features/merge_request/user_sees_mr_from_deleted_forked_project_spec.rb
+++ b/spec/features/merge_request/user_sees_mr_from_deleted_forked_project_spec.rb
@@ -1,18 +1,20 @@
 require 'rails_helper'
 
 describe 'Merge request > User sees MR from deleted forked project', :js do
+  include ProjectForksHelper
+
   let(:project) { create(:project, :public, :repository) }
   let(:user) { project.creator }
-  let(:fork_project) { create(:project, :public, :repository, forked_from_project: project) }
+  let(:forked_project) { fork_project(project, nil, repository: true) }
   let!(:merge_request) do
-    create(:merge_request_with_diffs, source_project: fork_project,
+    create(:merge_request_with_diffs, source_project: forked_project,
                                       target_project: project,
                                       description: 'Test merge request')
   end
 
   before do
     MergeRequests::MergeService.new(project, user).execute(merge_request)
-    fork_project.destroy!
+    forked_project.destroy!
     sign_in(user)
     visit project_merge_request_path(project, merge_request)
   end
diff --git a/spec/features/merge_request/user_sees_notes_from_forked_project_spec.rb b/spec/features/merge_request/user_sees_notes_from_forked_project_spec.rb
index d4ad0b0a377..a6118453540 100644
--- a/spec/features/merge_request/user_sees_notes_from_forked_project_spec.rb
+++ b/spec/features/merge_request/user_sees_notes_from_forked_project_spec.rb
@@ -1,18 +1,20 @@
 require 'rails_helper'
 
 describe 'Merge request > User sees notes from forked project', :js do
+  include ProjectForksHelper
+
   let(:project) { create(:project, :public, :repository) }
   let(:user) { project.creator }
-  let(:fork_project) { create(:project, :public, :repository, forked_from_project: project) }
+  let(:forked_project) { fork_project(project, nil, repository: true) }
   let!(:merge_request) do
-    create(:merge_request_with_diffs, source_project: fork_project,
+    create(:merge_request_with_diffs, source_project: forked_project,
                                       target_project: project,
                                       description: 'Test merge request')
   end
 
   before do
     create(:note_on_commit, note: 'A commit comment',
-                            project: fork_project,
+                            project: forked_project,
                             commit_id: merge_request.commit_shas.first)
     sign_in(user)
   end
diff --git a/spec/features/merge_request/user_sees_pipelines_from_forked_project_spec.rb b/spec/features/merge_request/user_sees_pipelines_from_forked_project_spec.rb
index d30dcefc6aa..97093bbc2f6 100644
--- a/spec/features/merge_request/user_sees_pipelines_from_forked_project_spec.rb
+++ b/spec/features/merge_request/user_sees_pipelines_from_forked_project_spec.rb
@@ -1,17 +1,19 @@
 require 'rails_helper'
 
 describe 'Merge request > User sees pipelines from forked project', :js do
+  include ProjectForksHelper
+
   let(:target_project) { create(:project, :public, :repository) }
   let(:user) { target_project.creator }
-  let(:fork_project) { create(:project, :repository, forked_from_project: target_project) }
+  let(:forked_project) { fork_project(target_project, nil, repository: true) }
   let!(:merge_request) do
-    create(:merge_request_with_diffs, source_project: fork_project,
+    create(:merge_request_with_diffs, source_project: forked_project,
                                       target_project: target_project,
                                       description: 'Test merge request')
   end
   let(:pipeline) do
     create(:ci_pipeline,
-           project: fork_project,
+           project: forked_project,
            sha: merge_request.diff_head_sha,
            ref: merge_request.source_branch)
   end