🐍 Fixing a `google-genai` Version Mismatch and Verifying the Behavior with pytest [1/3]

Introduction Hello from Japan! 🇯🇵 I am tosane932 , a professional truck driver working in logistics while teaching myself Python. In my previous article, I tested a Docker multi-stage build and measured the actual change in image size. At the end of that article, I said that I would write next about pytest and CI/CD. This article was supposed to be the practical follow-up. However, while preparing for that work, I encountered an unexpected side issue. I only intended to introduce Flask-Migrate. Instead, the pip installation logs revealed that the version of a library in my local development environment had been changed without me noticing. The library was: google-genai From there, I went through the following process: Identify the version mismatch Restore the version that had already been tested locally Update requirements.txt Manually verify the Gemini API functionality Run pytest to check for regressions This article records that process without hiding the inconvenient parts. https://github.com/tosane932/sales_data_app Overview While installing Flask-Migrate, I noticed a mismatch between: The version of google-genai installed in my local development environment The version declared in requirements.txt The local environment had been using: google-genai 2.10.0 However, requirements.txt still specified: google-genai==2.4.0 When I ran: pip install -r requirements.txt pip followed the configuration file and replaced the newer local version with the older declared version. This article explains how I discovered the issue, synchronized the environments, and verified the application behavior with automated tests. 1. The Problem and Its Background I was preparing to introduce Flask-Migrate. During that work, I ran: pip install -r requirements.txt The installation log contained the following lines: Attempting uninstall: google-genai Found existing installation: google-genai 2.10.0 Uninstalling google-genai-2.10.0: That message caught my attention. After checking the environ