add test to ensure seed is idempotent

db/seeds.rb

@@ -88,4 +88,4 @@
 end
 
 # reindex all talk in MeiliSearch
-Talk.reindex!
+Talk.reindex! unless Rails.env.test?

test/tasks/db_seed_test.rb

@@ -0,0 +1,22 @@
+require "test_helper"
+
+class DbSeedTest < ActiveSupport::TestCase
+  setup do
+    @event = events(:one)
+    Rails.application.load_tasks
+    Rake::Task["db:environment:set"].reenable
+    Rake::Task["db:schema:load"].invoke
+  end
+
+  test "db:seed runs successfully" do
+    assert_nothing_raised do
+      Rake::Task["db:seed"].invoke
+    end
+
+    # Ensuring idempotency
+    assert_no_difference "Talk.maximum(:created_at)" do
+      Rake::Task["db:seed"].reenable
+      Rake::Task["db:seed"].invoke
+    end
+  end
+end