Intercom Software Engineer Product interview questions

I sent an email, including my cv and soon got a reply which had 3 tasks to complete. One was a general question, and the other two were coding tasks. They prefer email screening rather than phone or skype talks. I don't like coding a lot on interview exercises, before I have the slightest idea that they are interested in me. Anyway I did the coding task, but I didn't write any tests for my code, and I think they main reason I got rejected was that.