I started my new job on the same day with another colleague. We both are senior software developers. The workload is manageable, so we both were looking for some side projects the company can benefit from.
He quickly found a small project that he completed in about 2 months. At first I offered to take part in it. Asked if I could help him, which he always denied because the project was too small.
Meanwhile I found my own bigger project, which I've been working on for over 4 months now. I would say it's about 80% complete. Suddenly my colleague asked me to explain my project to him. I proudly presented all the functions to him, including the problems that the project still has. He started to ask me questions and giving me suggestions. We use Git (tool for coordinating work among programmers collaboratively developing source code), so the source code is available to all developers within our company. He also wanted me to send him further data (access data, parameters for testing, etc.).
I independently recognized the need for that project, collected all information from other colleagues, read into complex topics and already wrote a lot of code. My supervisor is very happy with it and says that it would make our work a lot easier.
I understand that it is normal to work on projects with multiple developers, but the project does not have the dimension for additional developers. I don't want someone to jump in at the end of the project, add some code and then later claim that it is our project. We're both new to the company, so I don't know what kind of person my colleague is.
In our weekly team meetings, everyone shares what they're working on so everyone knows it's my project.
How can I make it clear to him that I don't want his help? I am able to complete the project on my own.