Agenda

  1. Warm-up: Name That Error β€” a traceback from a file you have never opened
  2. Read before you change: run it, find the entry point, name the nouns, follow one path, then change one small thing on purpose
  3. Launch: The Maintenance Sprint β€” extend and fix a program your team did not write, without breaking what already worked
  4. Sprint work period: run it, follow one path, then write the characterisation tests that capture what it already does β€” all of that before a single line is changed. Every commit gets a message a stranger could act on a year from now.

Things to do before our next class

  • Milestone: the inherited program runs on your machine, and you can say in one sentence what it does.
  • Project milestone: open your team’s first feature branch.