Rails测试遇ActiveRecord::NotNullViolation：created_at非空约束失败

使用 Ruby 3.3.3 + Rails 7.1.3.4 进行测试时，触发错误：ActiveRecord::NotNullViolation: RuntimeError: NOT NULL constraint failed: drives.created_at。根据 ActiveRecord 文档，Fixtures 应自动填充 created_at 字段，但当前项目无法实现该功能，干净的 Rails 环境中则正常运行。

相关代码与日志 #

Drive 模型代码 #

class Drive < ApplicationRecord
  with_options presence: true do
    validates :name
    validates :provider
    validates :credentials
  end

  encrypts :credentials
end

迁移文件代码 #

class CreateDrives < ActiveRecord::Migration[7.1]
  def change
    create_table :drives do |t|
      t.string :name
      t.string :provider
      t.text :credentials

      t.timestamps
    end
  end
end

Fixtures 代码 #

# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html

one:
  name: MyString
  provider: MyString
  credentials: MyText

two:
  name: MyString
  provider: MyString
  credentials: MyText

测试日志片段 #

[1m[36mTRANSACTION (0.0ms)[0m  [1m[36mbegin transaction[0m
  [1m[36mFixtures Load (0.2ms)[0m  [1m[31mDELETE FROM "drives";
INSERT INTO "drives" ("name", "provider", "credentials") VALUES ('MyString', 'MyString', 'MyText');
INSERT INTO "drives" ("name", "provider", "credentials") VALUES ('MyString', 'MyString', 'MyText')[0m
  [1m[36mTRANSACTION (0.0ms)[0m  [1m[31mrollback transaction[0m

排查与解决步骤 #

• 检查 Fixture 全局配置
  查看 test_helper.rb 或 config/application.rb，确认是否存在禁用自动时间戳填充的配置：

  # 若存在此行需移除
  ActiveRecord::FixtureSet.enable_transactional_fixtures = false
  

• 验证模型时间戳设置
  检查 Drive 模型是否禁用了自动时间戳记录，若有如下代码需移除：

  self.record_timestamps = false
  # 或
  self.ignored_columns = [:created_at, :updated_at]
  

• 排查加密字段干扰
  临时注释掉模型中的 encrypts :credentials 配置，重新运行测试。若恢复正常，需确认加密逻辑未修改模型初始化流程，可尝试更新 Rails 加密相关依赖或调整加密配置。

• 手动指定时间戳（临时方案）
  若以上方法无效，可在 Fixtures 文件中手动添加时间戳字段：

  one:
    name: MyString
    provider: MyString
    credentials: MyText
    created_at: <%= Time.now %>
    updated_at: <%= Time.now %>
  
  two:
    name: MyString
    provider: MyString
    credentials: MyText
    created_at: <%= Time.now %>
    updated_at: <%= Time.now %>
  

• 重置测试数据库
  执行以下命令确保测试数据库迁移正确：

  rails db:test:prepare
  

内容的提问来源于stack exchange，提问作者Ghassen Rjab