4 files changed, 36 insertions, 2 deletions
diff --git a/app/models/event.rb b/app/models/event.rb
index f0cc99a9242..e855ed02274 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -392,6 +392,9 @@ class Event < ActiveRecord::Base
   end
 
   def track_user_contributed_projects
-    UserContributedProjects.track(self)
+    # Note the call to .available? is due to earlier migrations
+    # that would otherwise conflict with the call to .track
+    # (because the table does not exist yet).
+    UserContributedProjects.track(self) if UserContributedProjects.available?
   end
 end
diff --git a/app/models/user_contributed_projects.rb b/app/models/user_contributed_projects.rb
index 1f8e9a3f480..2965b956f3f 100644
--- a/app/models/user_contributed_projects.rb
+++ b/app/models/user_contributed_projects.rb
@@ -7,6 +7,9 @@ class UserContributedProjects < ActiveRecord::Base
 
   CACHE_EXPIRY_TIME = 1.day
 
+  # Schema version required for this model
+  REQUIRED_SCHEMA_VERSION = 20180223120443
+
   class << self
     def track(event)
       # For events without a project, we simply don't care.
@@ -35,6 +38,11 @@ class UserContributedProjects < ActiveRecord::Base
       end
     end
 
+    # Check if we can safely call .track (table exists)
+    def available?
+      @available_flag ||= ActiveRecord::Migrator.current_version >= REQUIRED_SCHEMA_VERSION # rubocop:disable Gitlab/PredicateMemoization
+    end
+
     private
 
     def cached_exists?(project_id:, user_id:, &block)
diff --git a/spec/models/event_spec.rb b/spec/models/event_spec.rb
index 11f6ae74712..445de37d2b1 100644
--- a/spec/models/event_spec.rb
+++ b/spec/models/event_spec.rb
@@ -51,11 +51,19 @@ describe Event do
     end
 
     describe 'after_create :track_user_contributed_projects' do
+      let(:event) { build(:push_event, project: project, author: project.owner) }
+
       it 'passes event to UserContributedProjects.track' do
-        event = build(:push_event, project: project, author: project.owner)
+        expect(UserContributedProjects).to receive(:available?).and_return(true)
         expect(UserContributedProjects).to receive(:track).with(event)
         event.save
       end
+
+      it 'does not call UserContributedProjects.track if its not yet available' do
+        expect(UserContributedProjects).to receive(:available?).and_return(false)
+        expect(UserContributedProjects).not_to receive(:track)
+        event.save
+      end
     end
   end
 
diff --git a/spec/models/user_contributed_projects_spec.rb b/spec/models/user_contributed_projects_spec.rb
index f92a9d91f8b..092821c8aea 100644
--- a/spec/models/user_contributed_projects_spec.rb
+++ b/spec/models/user_contributed_projects_spec.rb
@@ -40,6 +40,21 @@ describe UserContributedProjects do
     end
   end
 
+  describe '.available?' do
+    before do
+      described_class.instance_variable_set('@available_flag', nil)
+    end
+
+    it 'checks schema version and properly caches positive result' do
+      expect(ActiveRecord::Migrator).to receive(:current_version).and_return(described_class::REQUIRED_SCHEMA_VERSION - 1 - rand(1000))
+      expect(described_class.available?).to be_falsey
+      expect(ActiveRecord::Migrator).to receive(:current_version).and_return(described_class::REQUIRED_SCHEMA_VERSION + rand(1000))
+      expect(described_class.available?).to be_truthy
+      expect(ActiveRecord::Migrator).not_to receive(:current_version)
+      expect(described_class.available?).to be_truthy # cached response
+    end
+  end
+
   it { is_expected.to validate_presence_of(:project) }
   it { is_expected.to validate_presence_of(:user) }
 end