Opional connection closing on shutdown hook

[n-nik]

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• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Currently, the SequelizeModule unconditionally closes the database connection during the onApplicationShutdown lifecycle hook. In applications that run long-running background tasks (e.g., RabbitMQ consumers), this creates a race condition. An active task may attempt a database query after the connection has been closed, leading to a ConnectionManager was closed error and preventing a truly graceful shutdown.

Issue Number: N/A

What is the new behavior?

This PR introduces a new boolean option, autoCloseConnection, to the module configuration options.

• It defaults to true to ensure full backward compatibility.
• When autoCloseConnection is set to false, the module will skip closing the connection during the shutdown lifecycle.

This gives developers control over the connection's lifecycle, allowing them to implement an orchestrated shutdown. For example, they can wait for all background tasks to complete before manually closing the Sequelize connection in their own onApplicationShutdown hook.

Does this PR introduce a breaking change?

• Yes
• No

Other information

This change enables more robust graceful shutdown patterns for applications with background workers. This PR also includes minor code formatting and dependency updates from npm audit fix to align with the project's standards.

Example Usage:

// In a module
SequelizeModule.forRoot({
  ...options,
  autoCloseConnection: false,
})

// In a custom shutdown service
@Injectable()
class CustomShutdownService implements OnApplicationShutdown {
  constructor(
    private readonly sequelize: Sequelize
  ) {}

  async onApplicationShutdown() {
    // Manually close the connection
    await this.sequelize.close();
  }
}