Controller testing

[s2oBCN]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

As said in this request: #9253
Dify is becoming increasingly unstable due to contributions. Even though the project is still in an early development phase, Dify is already being used in production environments.

Especially recently, breaking changes and critical errors have been introduced that have caused problems for many users.

2. Additional context or comments

Before creating e2e test, I think it is better to create integration tests.
I'll create a PR with an example of an integration test for the controllers.
In this case I created an IT that helped me identify some problems we had, but the IT that I will upload is just a simple example

3. Can you help us with this feature?

• I am interested in contributing to this feature.