Program slicing — finds the minimum set of statements that affect a value.

mix reach.trace lib/my_app/user_controller.ex:18
mix reach.trace MyApp.UserService.create/1 --variable changeset
mix reach.trace --forward lib/my_app/user_service.ex:30 --variable user
mix reach.trace lib/my_app_web/controllers/user_controller.ex:18 --format json

Options

• --forward — forward slice (where does this value flow to?)
• --variable — trace a specific variable name within the slice
• --format — output format: text (default), json, oneline