Fail when trying to join a nonexisting mob session

[simonharrer]

As a regular mob user in our remote team, we are doing trunk based development. When we want to work on a new story, the first one in the mob starts a new session with mob start -b STORY-1234-add-feature (or similar). After the handover with ´mob next´, the next person wants to continue with this session. So they also have to input the same command on their machine. We just tell the other person what the current "branch" name is (i.e. "Just join the session STORY-1234-add-feature"). However, when the person mispells the exact session name, then instead of joining the existing session, a new session is started. You then have to delete this session and retry with the correct name. The desired behaviour in our case would be to FAIL the mob start command IF the given session does not yet exist.

#socrates2024

Problem

# Alice
mob start -b STORY-1234-add-feature
# do so some work
mob next

# Bob
mob start -b STORY-123-add-feature
# we are on branch mob/STORY-123-add-feature, but we want to be on mob/STORY-1234-add-feature

Solution

# Alice
mob start -b STORY-1234-add-feature
# do so some work
mob next

# Bob
mob start -b STORY-123-add-feature --join # or use -j
# expectation: fails