Use safe_find_or_create_by to ensure build pending state

This also fixes `safe_find_or_create_by!` in case of arguments mismatch.

app/models/application_record.rb

@@ -48,6 +48,8 @@ class ApplicationRecord < ActiveRecord::Base
 
   def self.safe_find_or_create_by!(*args, &block)
     safe_find_or_create_by(*args, &block).tap do |record|
+      raise ActiveRecord::RecordNotFound unless record.present?
+
       record.validate! unless record.persisted?
     end
   end

app/services/ci/update_build_state_service.rb

@@ -163,16 +163,18 @@ module Ci
     end
 
     def ensure_pending_state
-      Ci::BuildPendingState.create_or_find_by!(
+      build_state = Ci::BuildPendingState.safe_find_or_create_by(
         build_id: build.id,
         state: params.fetch(:state),
         trace_checksum: params.fetch(:checksum),
         failure_reason: params.dig(:failure_reason)
       )
-    rescue ActiveRecord::RecordNotFound
-      metrics.increment_trace_operation(operation: :conflict)
 
-      build.pending_state
+      unless build_state.present?
+        metrics.increment_trace_operation(operation: :conflict)
+      end
+
+      build_state || build.pending_state
     end
 
     ##

spec/models/application_record_spec.rb

@@ -67,7 +67,8 @@ RSpec.describe ApplicationRecord do
       end
 
       it 'raises a validation error if the record was not persisted' do
-        expect { Suggestion.find_or_create_by!(note: nil) }.to raise_error(ActiveRecord::RecordInvalid)
+        expect { Suggestion.safe_find_or_create_by!(note: nil) }
+          .to raise_error(ActiveRecord::RecordInvalid)
       end
 
       it 'passes a block to find_or_create_by' do
@@ -75,6 +76,14 @@ RSpec.describe ApplicationRecord do
           Suggestion.safe_find_or_create_by!(suggestion_attributes, &block)
         end.to yield_with_args(an_object_having_attributes(suggestion_attributes))
       end
+
+      it 'raises a record not found error in case of attributes mismatch' do
+        suggestion = Suggestion.safe_find_or_create_by!(suggestion_attributes)
+        attributes = suggestion_attributes.merge(outdated: !suggestion.outdated)
+
+        expect { Suggestion.safe_find_or_create_by!(attributes) }
+          .to raise_error(ActiveRecord::RecordNotFound)
+      end
     end
   end