From cfa9613a8d750bacdffccc2f5b951208ee7f4127 Mon Sep 17 00:00:00 2001
From: Morgan Roderick <morgan@roderick.dk>
Date: Wed, 6 May 2026 12:15:35 +0200
Subject: [PATCH] fix: workshop capacity checks now properly compare attending
 count with available spaces

PR #2605 changed the capacity check methods from student_spaces?/
coach_spaces? to event_student_spaces?/event_coach_spaces?, but the
new methods in EventPresenter called model.student_spaces? which just
checks if the attribute is present (truthy), not if spaces are actually
available.

This fix adds proper event_student_spaces? and event_coach_spaces?
methods to WorkshopPresenter that correctly compare the number of
attending students/coaches with the available spaces from the workshop
model (using model.student_spaces and model.coach_spaces).

This ensures that:
- When 2 students attend a workshop with 2 spaces, event_student_spaces?
  returns false (correctly indicating the workshop is full)
- When 1 student attends a workshop with 2 spaces, event_student_spaces?
  returns true (correctly indicating space is available)

Fixes the bug where workshops showed as full even when spaces were
available, and vice versa.
---
 app/presenters/workshop_presenter.rb          |  8 ++
 .../workshop_presenter_capacity_spec.rb       | 75 +++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 spec/presenters/workshop_presenter_capacity_spec.rb

diff --git a/app/presenters/workshop_presenter.rb b/app/presenters/workshop_presenter.rb
index 84fecaa6d..ee4509171 100644
--- a/app/presenters/workshop_presenter.rb
+++ b/app/presenters/workshop_presenter.rb
@@ -74,6 +74,14 @@ def student_spaces
     venue.seats
   end
 
+  def event_student_spaces?
+    model.student_spaces > attending_students.length
+  end
+
+  def event_coach_spaces?
+    model.coach_spaces > attending_coaches.length
+  end
+
   def pairing_csv
     pairing_details = model.attendances.inject([PAIRING_HEADINGS]) do |content, invitation|
       member = MemberPresenter.new(invitation.member)
diff --git a/spec/presenters/workshop_presenter_capacity_spec.rb b/spec/presenters/workshop_presenter_capacity_spec.rb
new file mode 100644
index 000000000..6ba0e52ff
--- /dev/null
+++ b/spec/presenters/workshop_presenter_capacity_spec.rb
@@ -0,0 +1,75 @@
+require 'rails_helper'
+
+RSpec.describe 'WorkshopPresenter capacity checks', type: :model do
+  describe '#event_student_spaces?' do
+    let(:workshop) { Fabricate(:workshop, student_count: 2, coach_count: 2) }
+    let(:presenter) { WorkshopPresenter.new(workshop) }
+
+    context 'when workshop is at capacity' do
+      before do
+        # Create 2 attending students (at capacity)
+        2.times do
+          member = Fabricate(:member)
+          Fabricate(:workshop_invitation, workshop: workshop, member: member, role: 'Student', attending: true)
+        end
+      end
+
+      it 'returns false when no spaces are available' do
+        expect(workshop.attending_students.count).to eq(2)
+        expect(workshop.student_spaces).to eq(2)
+        expect(presenter.event_student_spaces?).to eq(false), 
+          "Expected event_student_spaces? to be false when at capacity (2/2), but got true"
+      end
+    end
+
+    context 'when workshop has available spaces' do
+      before do
+        # Create 1 attending student (below capacity)
+        member = Fabricate(:member)
+        Fabricate(:workshop_invitation, workshop: workshop, member: member, role: 'Student', attending: true)
+      end
+
+      it 'returns true when spaces are available' do
+        expect(workshop.attending_students.count).to eq(1)
+        expect(workshop.student_spaces).to eq(2)
+        expect(presenter.event_student_spaces?).to eq(true),
+          "Expected event_student_spaces? to be true when spaces available (1/2), but got false"
+      end
+    end
+  end
+
+  describe '#event_coach_spaces?' do
+    let(:workshop) { Fabricate(:workshop, student_count: 2, coach_count: 2) }
+    let(:presenter) { WorkshopPresenter.new(workshop) }
+
+    context 'when workshop is at coach capacity' do
+      before do
+        # Create 2 attending coaches (at capacity)
+        2.times do
+          member = Fabricate(:member)
+          Fabricate(:workshop_invitation, workshop: workshop, member: member, role: 'Coach', attending: true)
+        end
+      end
+
+      it 'returns false when no coach spaces are available' do
+        expect(workshop.attending_coaches.count).to eq(2)
+        expect(presenter.event_coach_spaces?).to eq(false),
+          "Expected event_coach_spaces? to be false when at capacity (2/2), but got true"
+      end
+    end
+
+    context 'when workshop has available coach spaces' do
+      before do
+        # Create 1 attending coach (below capacity)
+        member = Fabricate(:member)
+        Fabricate(:workshop_invitation, workshop: workshop, member: member, role: 'Coach', attending: true)
+      end
+
+      it 'returns true when coach spaces are available' do
+        expect(workshop.attending_coaches.count).to eq(1)
+        expect(presenter.event_coach_spaces?).to eq(true),
+          "Expected event_coach_spaces? to be true when spaces available (1/2), but got false"
+      end
+    end
+  end
+end