Assure commit_count is set after migration cleanupjprovazn-migrate-missing-commit-counts

!17513 cleaned up migration which adds commit_count to
MergeRequestDiffs. It's also necessary to assure that there
are not any records with commit_count unset (in case sidekiq
queue was killed for example).

Related to #41698

3 files changed, 60 insertions, 1 deletions

diff --git a/db/migrate/20180306131009_assure_commits_count_for_merge_request_diff.rb b/db/migrate/20180306131009_assure_commits_count_for_merge_request_diff.rb
new file mode 100644
index 00000000000..9172146e3f9
--- /dev/null
+++ b/db/migrate/20180306131009_assure_commits_count_for_merge_request_diff.rb
@@ -0,0 +1,27 @@
+class AssureCommitsCountForMergeRequestDiff < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class MergeRequestDiff < ActiveRecord::Base
+    self.table_name = 'merge_request_diffs'
+
+    include ::EachBatch
+  end
+
+  def up
+    # Background migration queue is cleaned up in
+    # db/migrate/20180304204842_clean_commits_count_migration.rb.
+    MergeRequestDiff.where(commits_count: nil).each_batch(of: 50) do |batch|
+      range = batch.pluck('MIN(id)', 'MAX(id)').first
+
+      Gitlab::BackgroundMigration::AddMergeRequestDiffCommitsCount.new.perform(*range)
+    end
+  end
+
+  def down
+    # noop
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 0881a1af945..d4f3a088473 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180305144721) do
+ActiveRecord::Schema.define(version: 20180306131009) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
diff --git a/spec/migrations/assure_commits_count_for_merge_request_diff_spec.rb b/spec/migrations/assure_commits_count_for_merge_request_diff_spec.rb
new file mode 100644
index 00000000000..ea252b24cc6
--- /dev/null
+++ b/spec/migrations/assure_commits_count_for_merge_request_diff_spec.rb
@@ -0,0 +1,32 @@
+require 'spec_helper'
+require Rails.root.join('db', 'migrate', '20180306131009_assure_commits_count_for_merge_request_diff.rb')
+
+describe AssureCommitsCountForMergeRequestDiff, :migration, :sidekiq, :redis do
+  let(:migration) { spy('migration') }
+
+  before do
+    allow(Gitlab::BackgroundMigration::AddMergeRequestDiffCommitsCount)
+      .to receive(:new).and_return(migration)
+  end
+
+  context 'when there are still unmigrated commit_counts afterwards' do
+    let(:namespaces) { table('namespaces') }
+    let(:projects) { table('projects') }
+    let(:merge_requests) { table('merge_requests') }
+    let(:diffs) { table('merge_request_diffs') }
+
+    before do
+      namespace = namespaces.create(name: 'foo', path: 'foo')
+      project = projects.create!(namespace_id: namespace.id)
+      merge_request = merge_requests.create!(source_branch: 'x', target_branch: 'y', target_project_id: project.id)
+      diffs.create!(commits_count: nil, merge_request_id: merge_request.id)
+      diffs.create!(commits_count: nil, merge_request_id: merge_request.id)
+    end
+
+    it 'migrates commit_counts sequentially in batches' do
+      migrate!
+
+      expect(migration).to have_received(:perform).once
+    end
+  end
+end