Gracefully handle SQL parse errors in Sentry error tracker

If a SQL query cannot be parsed, previously the Sentry error tracker
would throw a `PgQuery::ParseError` instead of handling it gracefully.
This commit fixes a spec failure that occurred when a bad SQL query gets
caught by the cross-join detector and bubbles up to the Sentry error
tracker.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/348207

lib/gitlab/error_tracking.rb

@@ -142,11 +142,18 @@ module Gitlab
       def inject_context_for_exception(event, ex)
         case ex
         when ActiveRecord::StatementInvalid
-          event.extra[:sql] = PgQuery.normalize(ex.sql.to_s)
+          # StatementInvalid may be caused by a statement timeout or a bad query
+          event.extra[:sql] = normalize_query(ex.sql.to_s)
         else
           inject_context_for_exception(event, ex.cause) if ex.cause.present?
         end
       end
+
+      def normalize_query(sql)
+        PgQuery.normalize(sql)
+      rescue PgQuery::ParseError
+        sql
+      end
     end
   end
 end

spec/lib/gitlab/error_tracking_spec.rb

@@ -215,6 +215,16 @@ RSpec.describe Gitlab::ErrorTracking do
         expect(sentry_event.dig('extra', 'sql')).to eq('SELECT "users".* FROM "users" WHERE "users"."id" = $2 AND "users"."foo" = $1')
       end
     end
+
+    context 'when the `ActiveRecord::StatementInvalid` is a bad query' do
+      it 'injects the query as-is into extra' do
+        allow(exception).to receive(:cause).and_return(ActiveRecord::StatementInvalid.new(sql: 'SELECT SELECT FROM SELECT'))
+
+        track_exception
+
+        expect(sentry_event.dig('extra', 'sql')).to eq('SELECT SELECT FROM SELECT')
+      end
+    end
   end
 
   context 'event processors' do