turniere-backend/spec/e2e_known_behaviors.md

Backend E2E Known Behaviors

This file records non-obvious backend behaviors that the E2E suite intentionally preserves.

Group-stage tournaments cannot finish the playoff final through the normal match endpoint

Observed and covered by spec/requests/e2e/tournament_lifecycle_spec.rb:

• in tournaments that started with a group stage, the playoff final can be started and scored
• but PATCH /matches/:id with state=finished on that final returns:
  • status 422
  • error "Moving Team one stage down failed"
• the final remains in_progress

This appears to happen because playoff stages count down to level 0, while the old group stage still exists at level -1. The final-finish flow looks for a "stage below" using current_stage.level - 1, which resolves to the group stage for finals in group-stage tournaments. The E2E suite preserves this current behavior instead of changing backend code.

Group stage to playoff conversion with 3 groups and playoff_teams_amount = 4

Observed and covered by spec/requests/e2e/tournament_lifecycle_spec.rb:

• instant_finalists_amount becomes 3
• intermediate_round_participants_amount becomes 2
• this means 5 teams advance out of the group stage into the playoff tree
• the resulting playoff entry stage is an intermediate_stage with:
  • 3 single_team matches
  • 1 regular match

This can look surprising if playoff_teams_amount = 4 is read as "exactly four teams leave the group stage". The current backend instead models "four playoff slots after the intermediate round", which is the behavior the new E2E tests lock in.