feat: Solid Cable channel browser

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Solid Cable channel browser — `GET /cable` lists all distinct channels with per-channel message count and last-message timestamp, ordered by most recent activity; a total-messages stat and channel-count stat are shown at the top; empty state shown when no messages exist; Cable subnav (Overview) added to the layout
+
 ## [0.5.0] - 2026-05-26
 
 ### Added

app/controllers/solid_stack_web/cable_controller.rb

@@ -2,7 +2,20 @@ module SolidStackWeb
   class CableController < ApplicationController
     def index
       @total_messages = ::SolidCable::Message.count
-      @channels       = ::SolidCable::Message.distinct.pluck(:channel).sort
+      @channels       = channel_rows
+    end
+
+    private
+
+    def channel_rows
+      ::SolidCable::Message
+        .group(:channel)
+        .order(Arel.sql("MAX(created_at) DESC"))
+        .pluck(:channel, Arel.sql("COUNT(*)"), Arel.sql("MAX(created_at)"))
+        .map do |ch, cnt, last_at|
+          last_at = Time.zone.parse(last_at) if last_at.is_a?(String)
+          { channel: ch, message_count: cnt, last_message_at: last_at }
+        end
     end
   end
 end

app/views/layouts/solid_stack_web/application.html.erb

@@ -35,6 +35,15 @@
     </nav>
   <% end %>
 
+  <% if current_section == :cable %>
+    <nav class="sqw-subnav">
+      <div class="sqw-subnav__inner">
+        <%= link_to "Overview", cable_path,
+              class: "sqw-subnav__link#{" sqw-subnav__link--active" if controller_name == "cable"}" %>
+      </div>
+    </nav>
+  <% end %>
+
   <% if current_section == :queue %>
     <nav class="sqw-subnav">
       <div class="sqw-subnav__inner">

app/views/solid_stack_web/cable/index.html.erb

@@ -16,12 +16,24 @@
 <% if @channels.any? %>
   <table class="sqw-table">
     <thead>
-      <tr><th>Channel</th></tr>
+      <tr>
+        <th>Channel</th>
+        <th>Messages</th>
+        <th>Last Message</th>
+      </tr>
     </thead>
     <tbody>
       <% @channels.each do |channel| %>
-        <tr><td class="sqw-monospace"><%= channel %></td></tr>
+        <tr>
+          <td class="sqw-monospace"><%= channel[:channel] %></td>
+          <td><%= channel[:message_count] %></td>
+          <td class="sqw-muted"><%= channel[:last_message_at]&.strftime("%b %d %H:%M") %></td>
+        </tr>
       <% end %>
     </tbody>
   </table>
+<% else %>
+  <div class="sqw-empty">
+    <p>No cable messages.</p>
+  </div>
 <% end %>

spec/rails_helper.rb

@@ -16,4 +16,5 @@
   config.use_transactional_fixtures = true
   config.infer_spec_type_from_file_location!
   config.filter_rails_from_backtrace!
+  config.include ActiveSupport::Testing::TimeHelpers
 end

spec/requests/solid_stack_web/cable_spec.rb

@@ -42,9 +42,36 @@
 
       get "#{engine_root}/cable"
 
-      # 2 distinct channels, stat value should be 2 (not 3 messages)
       expect(response.body).to include("Channels")
       expect(response.body).to match(/class="sqw-stat__value">\s*2\s*</)
     end
+
+    it "shows message count and last message time per channel" do
+      SolidCable::Message.broadcast("sports:scores", "goal!")
+      SolidCable::Message.broadcast("sports:scores", "offside")
+
+      get "#{engine_root}/cable"
+
+      expect(response.body).to include("sports:scores")
+      expect(response.body).to include("Messages")
+      expect(response.body).to include("Last Message")
+    end
+
+    it "orders channels by most recent message first" do
+      SolidCable::Message.broadcast("older:channel", "first")
+      travel 1.second do
+        SolidCable::Message.broadcast("newer:channel", "second")
+      end
+
+      get "#{engine_root}/cable"
+
+      expect(response.body.index("newer:channel")).to be < response.body.index("older:channel")
+    end
+
+    it "shows empty state when no messages exist" do
+      SolidCable::Message.delete_all
+      get "#{engine_root}/cable"
+      expect(response.body).to include("No cable messages")
+    end
   end
 end