Add self-service event creation from nodes#show

nodes#show's events table now renders unconditionally (previously
hidden entirely for a zero-event node) and gains an "add event" link.
The suggested tag_list is derived from the page's own category tags
via NodesHelper::DEFAULT_EVENT_TAG_BY_PAGE_TAG (erfa-detail/
chaostreff-detail -> open-day) rather than hardcoded, and degrades to
a blank field for any node whose tags don't match - deliberately
universal, not chapter-specific, since Updates have historically
carried event dates the same way.

events#new surfaces *why* the tag was pre-filled via flash.now (not
flash - this is a same-request render, not a redirect), using an
explicit auto_tag_source param passed alongside tag_list rather than
having the controller re-derive the reason from node_id.

No destroy link added to nodes#show's events list - deliberate, per
existing subnav-semantics convention (destructive actions live on the
resource's own views). Covered directly by test.

Adds real coverage for EventsController, previously 100% commented-out
scaffold, plus unit tests for the new tag-mapping helper and the
weekday-abbreviation helpers from the prior commit.

5 files changed, 199 insertions, 41 deletions

diff --git a/test/controllers/events_controller_test.rb b/test/controllers/events_controller_test.rb
index 14e534e..9371ca7 100644
--- a/test/controllers/events_controller_test.rb
+++ b/test/controllers/events_controller_test.rb
@@ -1,45 +1,130 @@
 require 'test_helper'
 
 class EventsControllerTest < ActionController::TestCase
-  # test "should get index" do
-  #   get :index
-  #   assert_response :success
-  #   assert_not_nil assigns(:events)
-  # end
-  # 
-  # test "should get new" do
-  #   get :new
-  #   assert_response :success
-  # end
-  # 
-  # test "should create event" do
-  #   assert_difference('Event.count') do
-  #     post :create, params: { :event => { } }
-  #   end
-  # 
-  #   assert_redirected_to event_path(assigns(:event))
-  # end
-  # 
-  # test "should show event" do
-  #   get :show, params: { :id => events(:one).to_param }
-  #   assert_response :success
-  # end
-  # 
-  # test "should get edit" do
-  #   get :edit, params: { :id => events(:one).to_param }
-  #   assert_response :success
-  # end
-  # 
-  # test "should update event" do
-  #   put :update, params: { :id => events(:one).to_param, :event => { } }
-  #   assert_redirected_to event_path(assigns(:event))
-  # end
-  # 
-  # test "should destroy event" do
-  #   assert_difference('Event.count', -1) do
-  #     delete :destroy, params: { :id => events(:one).to_param }
-  #   end
-  # 
-  #   assert_redirected_to events_path
-  # end
+
+  test "should get index" do
+    login_as :quentin
+    get :index
+    assert_response :success
+    assert_not_nil assigns(:events)
+  end
+
+  test "should get new" do
+    login_as :quentin
+    get :new
+    assert_response :success
+  end
+
+  test "new pre-fills tag_list and explains it via flash when auto_tag_source is given" do
+    login_as :quentin
+    node = create_node_with_published_page
+
+    get :new, params: { node_id: node.id, tag_list: "open-day", auto_tag_source: "erfa-detail" }
+
+    assert_response :success
+    assert_equal "open-day", assigns(:event).tag_list.to_s
+    assert_match "open-day", flash[:notice]
+    assert_match "erfa-detail", flash[:notice]
+  end
+
+  test "new does not flash without an auto_tag_source" do
+    login_as :quentin
+
+    get :new, params: { tag_list: "open-day" }
+
+    assert_response :success
+    assert_nil flash[:notice]
+  end
+
+  test "new with no params renders a blank, unflashed form" do
+    login_as :quentin
+
+    get :new
+
+    assert_response :success
+    assert_nil assigns(:event).tag_list.presence
+    assert_nil flash[:notice]
+  end
+
+  test "should show event" do
+    login_as :quentin
+    node  = create_node_with_published_page
+    event = Event.create!(node_id: node.id, start_time: Time.now, end_time: Time.now + 1.hour)
+
+    get :show, params: { id: event.id }
+    assert_response :success
+  end
+
+  test "should get edit" do
+    login_as :quentin
+    node  = create_node_with_published_page
+    event = Event.create!(node_id: node.id, start_time: Time.now, end_time: Time.now + 1.hour)
+
+    get :edit, params: { id: event.id }
+    assert_response :success
+  end
+
+  test "should create event attached to a node" do
+    login_as :quentin
+    node = create_node_with_published_page
+
+    assert_difference('Event.count') do
+      post :create, params: {
+        event: {
+          node_id:    node.id,
+          start_time: Time.now,
+          end_time:   Time.now + 1.hour,
+          tag_list:   "open-day"
+        }
+      }
+    end
+
+    assert_redirected_to edit_node_path(node)
+    assert_equal 'Event was successfully created.', flash[:notice]
+  end
+
+  test "should not create an event without a title or a node_id" do
+    login_as :quentin
+
+    assert_no_difference('Event.count') do
+      post :create, params: { event: { start_time: Time.now, end_time: Time.now + 1.hour } }
+    end
+
+    assert_response :success # re-renders :new, not a redirect
+  end
+
+  test "should honour return_to on create" do
+    login_as :quentin
+    node = create_node_with_published_page
+
+    post :create, params: {
+      event:     { node_id: node.id, start_time: Time.now, end_time: Time.now + 1.hour },
+      return_to: node_path(node)
+    }
+
+    assert_redirected_to node_path(node)
+  end
+
+  test "should update event" do
+    login_as :quentin
+    node  = create_node_with_published_page
+    event = Event.create!(node_id: node.id, start_time: Time.now, end_time: Time.now + 1.hour)
+
+    put :update, params: { id: event.id, event: { title: "Updated title" } }
+
+    assert_redirected_to events_path
+    assert_equal "Updated title", event.reload.title
+  end
+
+  test "should destroy event" do
+    login_as :quentin
+    node  = create_node_with_published_page
+    event = Event.create!(node_id: node.id, start_time: Time.now, end_time: Time.now + 1.hour)
+
+    assert_difference('Event.count', -1) do
+      delete :destroy, params: { id: event.id }
+    end
+
+    assert_redirected_to events_url
+  end
 end
diff --git a/test/controllers/nodes_controller_test.rb b/test/controllers/nodes_controller_test.rb
index 53799f1..f14e27c 100644
--- a/test/controllers/nodes_controller_test.rb
+++ b/test/controllers/nodes_controller_test.rb
@@ -379,4 +379,37 @@ class NodesControllerTest < ActionController::TestCase
     get :index
   end
 
+  test "show renders events row and add-link for zero-event chapter node" do
+    login_as :quentin
+    node = create_node_with_published_page
+    node.head.tag_list = "erfa-detail"
+    node.head.save!
+
+    get :show, params: { id: node.id }
+    assert_response :success
+    assert_select "a", text: "add event"
+    assert_select "a[href*='tag_list=open-day']"
+    assert_select "a[href*='auto_tag_source=erfa-detail']"
+  end
+
+  test "show renders events row without a tag default for untagged node" do
+    login_as :quentin
+    node = create_node_with_published_page
+
+    get :show, params: { id: node.id }
+    assert_response :success
+    assert_select "a", text: "add event"
+    assert_select "a[href*='tag_list=']", count: 0
+  end
+
+  test "show never renders a destroy link for events" do
+    login_as :quentin
+    node = create_node_with_published_page
+    Event.create!(node_id: node.id, start_time: Time.now, end_time: Time.now + 1.hour)
+
+    get :show, params: { id: node.id }
+    assert_response :success
+    assert_select "form.button_to.destructive", count: 0
+  end
+
 end
diff --git a/test/models/concerns/rrule_humanizer_test.rb b/test/models/concerns/rrule_humanizer_test.rb
index 500dbc7..279ff73 100644
--- a/test/models/concerns/rrule_humanizer_test.rb
+++ b/test/models/concerns/rrule_humanizer_test.rb
@@ -81,4 +81,19 @@ class RruleHumanizerTest < ActiveSupport::TestCase
   test "falls back to english for unknown locale" do
     assert_equal "Every Tuesday", humanize("FREQ=WEEKLY;BYDAY=TU", :fr)
   end
+
+  test "wday_abbr returns the correct German abbreviation for each day" do
+    monday = Time.parse("2026-07-06") # confirmed Monday
+    assert_equal "Mo", RruleHumanizer.wday_abbr(monday, :de)
+    assert_equal "Di", RruleHumanizer.wday_abbr(monday + 1.day, :de)
+    assert_equal "Mi", RruleHumanizer.wday_abbr(monday + 2.days, :de)
+    assert_equal "Do", RruleHumanizer.wday_abbr(monday + 3.days, :de)
+    assert_equal "Fr", RruleHumanizer.wday_abbr(monday + 4.days, :de)
+    assert_equal "Sa", RruleHumanizer.wday_abbr(monday + 5.days, :de)
+    assert_equal "So", RruleHumanizer.wday_abbr(monday + 6.days, :de)
+  end
+
+  test "wday_abbr falls back to :de for an unrecognized locale" do
+    assert_equal "Mo", RruleHumanizer.wday_abbr(Time.parse("2026-07-06"), :fr)
+  end
 end
diff --git a/test/models/helpers/content_helper_test.rb b/test/models/helpers/content_helper_test.rb
index 2da82d7..a7ed478 100644
--- a/test/models/helpers/content_helper_test.rb
+++ b/test/models/helpers/content_helper_test.rb
@@ -1,4 +1,8 @@
 require 'test_helper'
 
 class ContentHelperTest < ActionView::TestCase
+  test "weekday_abbr delegates through the current I18n locale" do
+    I18n.locale = :de
+    assert_equal "Mo", weekday_abbr(Time.parse("2026-07-06"))
+  end
 end
diff --git a/test/models/helpers/nodes_helper_test.rb b/test/models/helpers/nodes_helper_test.rb
index 13011de..5d91a88 100644
--- a/test/models/helpers/nodes_helper_test.rb
+++ b/test/models/helpers/nodes_helper_test.rb
@@ -1,4 +1,25 @@
 require 'test_helper'
 
 class NodesHelperTest < ActionView::TestCase
+  FakePage = Struct.new(:tag_list)
+
+  test "default_event_tag_mapping matches erfa-detail" do
+    page = FakePage.new(["erfa-detail"])
+    assert_equal ["erfa-detail", "open-day"], default_event_tag_mapping(page)
+  end
+
+  test "default_event_tag_mapping matches chaostreff-detail" do
+    page = FakePage.new(["chaostreff-detail"])
+    assert_equal ["chaostreff-detail", "open-day"], default_event_tag_mapping(page)
+  end
+
+  test "default_event_tag_mapping returns nil for unrelated tags" do
+    page = FakePage.new(["update"])
+    assert_nil default_event_tag_mapping(page)
+  end
+
+  test "default_event_tag_list is nil without a matching tag" do
+    page = FakePage.new([])
+    assert_nil default_event_tag_list(page)
+  end
 end