ダッシュボードに今が学習予定時間の人を表示する

app/components/users/current_user_icon_list_component.html.slim

@@ -0,0 +1,16 @@
+.current-user-icon-list
+  .l-container
+    .current-user-icon-list__inner
+      h2.current-user-icon-list__title
+        span.current-user-icon-list__title-label
+          | 現在学習中
+        br
+        span.current-user-icon-list__title-time
+          = time_range(Time.zone.now)
+      ul.current-user-icon-list__items
+        - @users.each do |user|
+          li.current-user-icon-list__item
+            = render 'users/icon',
+              user: user,
+              link_class: 'current-users__item-link',
+              image_class: 'current-users__item-icon'

app/components/users/current_user_icon_list_component.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Users::CurrentUserIconListComponent < ViewComponent::Base
+  include TimeRangeHelper
+
+  def initialize(users:)
+    @users = users
+  end
+end

app/controllers/home_controller.rb

@@ -53,6 +53,7 @@ def display_dashboard
     @calendar = NicoNicoCalendar.new(current_user, params[:niconico_calendar])
     @target_end_date = GrassDateParameter.new(params[:end_date]).target_end_date
     @times = Grass.times(current_user, @target_end_date)
+    @users_for_time_slot = User.currently_learning_except(current_user)
   end
 
   def display_events_on_dashboard

app/helpers/time_range_helper.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module TimeRangeHelper
+  def time_range(time)
+    start_hour = time.change(min: 0, sec: 0)
+    end_hour = start_hour + 1.hour
+
+    "(#{I18n.t('date.abbr_day_names')[time.wday]}) #{start_hour.strftime('%H:%M')} 〜 #{end_hour.strftime('%H:%M')}"
+  end
+end

app/javascript/stylesheets/application.sass

@@ -20,6 +20,7 @@
 
 @import application/blocks/course/courses
 
+@import application/blocks/dashboard/current-user-icon-list
 @import application/blocks/dashboard/dashboard-categories-item
 @import application/blocks/dashboard/dashboard-contents
 @import application/blocks/dashboard/welcome-message

app/javascript/stylesheets/application/blocks/dashboard/_current-user-icon-list.sass

@@ -0,0 +1,38 @@
+.current-user-icon-list
+  margin-bottom: 1rem
+  background-color: #eaeaf1
+  padding-block: .5rem
+  // fallback for older UA
+  padding-top: .5rem
+  padding-bottom: .5rem
+
+.current-user-icon-list__inner
+  display: flex
+  align-items: center
+  gap: .5rem
+
+.current-user-icon-list__items
+  display: flex
+  align-items: center
+  gap: .25rem
+  flex: 1 1 auto
+  min-width: 0
+  flex-wrap: nowrap
+  overflow-x: auto
+  scrollbar-gutter: stable both-edges
+
+.current-user-icon-list__item
+  flex: 0 0 2.5rem
+  +media-breakpoint-up(md)
+    flex: 0 0 3rem
+  +media-breakpoint-down(sm)
+    flex: 0 0 2rem
+
+.current-user-icon-list__title-label
+  +text-block(.875rem 1.4)
+  font-weight: 700
+  white-space: nowrap
+
+.current-user-icon-list__title-time
+  +text-block(.75rem 1.4)
+  white-space: nowrap

app/models/learning_time_frame.rb

@@ -5,4 +5,12 @@ class LearningTimeFrame < ApplicationRecord
   has_many :users, through: :learning_time_frames_users
 
   validates :week_day, :activity_time, presence: true
+
+  scope :active_now, lambda {
+    now = Time.current
+    weekday = I18n.t('date.abbr_day_names')[now.wday]
+    hour = now.hour
+
+    where(week_day: weekday, activity_time: hour)
+  }
 end

app/models/user.rb

@@ -487,6 +487,14 @@ class User < ApplicationRecord # rubocop:todo Metrics/ClassLength
     :description
   )
 
+  scope :currently_learning_except, lambda { |user|
+    students_and_trainees
+      .joins(:learning_time_frames)
+      .merge(LearningTimeFrame.active_now)
+      .where.not(id: user.id)
+      .with_attached_avatar
+  }
+
   class << self
     def notification_receiver(target)
       case target

app/views/home/index.html.slim

@@ -12,6 +12,10 @@
 
 .page-body.is-dash-board
   .page-body__inner.has-side-nav
+
+    - if @users_for_time_slot.present?
+      = render Users::CurrentUserIconListComponent.new(users: @users_for_time_slot)
+
     - if current_user.adviser?
       = render 'adviser_dashboard'
     - elsif current_user.mentor?

db/schema.rb

@@ -957,8 +957,6 @@
     t.text "mentor_memo"
     t.text "after_graduation_hope"
     t.date "training_ends_on"
-    t.boolean "negative_streak", default: false, null: false
-    t.integer "last_negative_report_id"
     t.datetime "last_activity_at"
     t.datetime "hibernated_at"
     t.string "profile_name"
@@ -979,6 +977,8 @@
     t.integer "career_path", default: 0, null: false
     t.text "career_memo"
     t.boolean "sent_student_before_auto_retire_mail", default: false
+    t.integer "last_negative_report_id"
+    t.boolean "negative_streak", default: false, null: false
     t.datetime "training_completed_at"
     t.index ["course_id"], name: "index_users_on_course_id"
     t.index ["email"], name: "index_users_on_email", unique: true

test/components/users/current_user_icon_list_component_test.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class CurrentUserIconListComponentTest < ViewComponent::TestCase
+  fixtures :users, :learning_time_frames
+
+  test 'shows user icons if multiple users have active learning time now' do
+    travel_to Time.zone.local(2025, 5, 28, 12, 0, 0) do
+      kimura = users(:kimura)
+      kensyu = users(:kensyu)
+
+      LearningTimeFramesUser.create!(user: kimura, learning_time_frame_id: 85)
+      LearningTimeFramesUser.create!(user: kensyu, learning_time_frame_id: 85)
+
+      users = User.students_and_trainees.joins(:learning_time_frames).merge(LearningTimeFrame.active_now)
+      assert_includes users, kimura
+      assert_includes users, kensyu
+    end
+  end
+
+  test 'excludes current user from the list even when they have active learning time' do
+    travel_to Time.zone.local(2025, 5, 28, 12, 0, 0) do
+      kimura = users(:kimura)
+      kensyu = users(:kensyu)
+      current_user = users(:hatsuno)
+
+      LearningTimeFramesUser.create!(user: kimura, learning_time_frame_id: 85)
+      LearningTimeFramesUser.create!(user: kensyu, learning_time_frame_id: 85)
+      LearningTimeFramesUser.create!(user: current_user, learning_time_frame_id: 85)
+
+      users_for_time_slot = User.students_and_trainees
+                                .joins(:learning_time_frames)
+                                .merge(LearningTimeFrame.active_now)
+                                .where.not(id: current_user.id)
+
+      assert_includes users_for_time_slot, kimura
+      assert_includes users_for_time_slot, kensyu
+      assert_not_includes users_for_time_slot, current_user
+    end
+  end
+end

test/fixtures/learning_time_frames.yml

@@ -1,9 +1,9 @@
 <% week_days = { '日' => 'sun', '月' => 'mon', '火' => 'tue', '水' => 'wed', '木' => 'thu', '金' => 'fri', '土' => 'sat' } %>
 <% week_days.each_with_index do |(day_name, day_prefix), day_index| %>
-  <% (0..23).each_with_index do |hour, hour_index| %>
-  <%= "#{day_prefix}#{hour}:" %>
-    id: <%= day_index * 24 + hour_index + 1 %>
-    week_day: <%= day_name %>
-    activity_time: <%= hour %>
-  <% end %>
+<% (0..23).each_with_index do |hour, hour_index| %>
+<%= "#{day_prefix}#{hour}:" %>
+  id: <%= day_index * 24 + hour_index + 1 %>
+  week_day: <%= day_name %>
+  activity_time: <%= hour %>
+<% end %>
 <% end %>

test/helpers/time_range_helper_test.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class TimeRangeHelperTest < ActionView::TestCase
+  test 'formats weekday and time correctly' do
+    time = Time.zone.local(2025, 8, 29, 14, 30)
+    assert_equal '(金) 14:00 〜 15:00', time_range(time)
+  end
+
+  test 'formats exactly on the hour' do
+    time = Time.zone.local(2025, 8, 29, 10, 0)
+    assert_equal '(金) 10:00 〜 11:00', time_range(time)
+  end
+
+  test 'formats time crossing midnight' do
+    time = Time.zone.local(2025, 8, 31, 23, 59)
+    assert_equal '(日) 23:00 〜 00:00', time_range(time)
+  end
+end