Add admin page to show current test track assignments

For longer running experiments with a specific audience in my mind (like
preferred beta testers) it's useful to use the bulk assignments
capability to enable those features. However if there are mulitple
instances of "adding users to the beta", one doesn't have visibility
into what assignments may already be present.  This view is intended to
give admins more confidence that the intended assignments are in place.

Author: stevenjackson

app/assets/stylesheets/components/_tables.scss

@@ -129,6 +129,16 @@ mixin for generating a standard table
   @include standard-table(100%, 15%, 45%);
 }
 
+.FormulaTable {
+  @include standard-table(100%, 15%, 45%);
+  thead tr:first-child:not(tr:last-child) th {
+    border-bottom: none
+  }
+  tr td:last-child, th:last-child {
+    border-left: 4px double var(--color-border-default);
+  }
+}
+
 .EmptyTable {
   &--centered {
     text-align: center;

app/components/flash_component.rb

@@ -23,7 +23,7 @@ def banner_args(type)
   end
 
   def flash_types
-    %i(error success)
+    %i(error success warning)
   end
 
   def scheme_types

app/controllers/admin/split_assignments_controller.rb

@@ -0,0 +1,10 @@
+class Admin::SplitAssignmentsController  < AuthenticatedAdminController
+  VIEW_LIMIT = 1000
+
+  def index
+    split = Split.find(params.require(:split_id))
+    @split_name = split.name
+    @assignments = split.assignments.includes(visitor: { identifiers: :identifier_type }).order(updated_at: :desc).limit(VIEW_LIMIT)
+    flash.now[:warning] = "Only showing #{VIEW_LIMIT} of #{split.assignments.count} assignments" if split.assignments.count > VIEW_LIMIT
+  end
+end

app/views/admin/split_assignments/index.html.erb

@@ -0,0 +1,27 @@
+<article class="InfoCard py-5">
+  <div class="InfoCard-titleContainer">
+    <h1> <%= @split_name %> Assignments</h1>
+  </div>
+  <hr class="InfoCard-divider">
+  <div class="InfoCard-description">
+    <table class="FormulaTable">
+      <thead>
+        <tr><th colspan=2>Match visitor by</th><th>Set split to</th></tr>
+        <tr><th>attribute</th><th>value</th><th>variant</th></tr>
+      </thead>
+      <tbody>
+        <% @assignments.group_by(&:variant).each do |variant, assignments| %>
+          <% assignments.map(&:visitor).flat_map(&:identifiers).group_by { |identifier| identifier.identifier_type }.each do |type, identifiers| %>
+            <% identifiers.each do |identifier| %>
+              <tr>
+              <td ><%= type.name%></td>
+              <td ><%= identifier.value%></td>
+              <td><%= variant %></td>
+              </tr>
+              <%end %>
+          <% end %>
+        <% end %>
+      </tbody>
+    </table>
+  </div>
+</article>

app/views/admin/splits/_details.html.erb

@@ -10,7 +10,7 @@
         <td>Population Size</td>
         <td>
           <span class='population'>
-            <%= @split.assignments.count %><% if @split.feature_gate? %>* [<a href="#gate_population">feature gate</a>]<% end %>
+            <%= link_to @split.assignments.count, admin_split_assignments_path(split) %><% if @split.feature_gate? %>* [<a href="#gate_population">feature gate</a>]<% end %>
           </span>
         </td>
         <td>

config/routes.rb

@@ -111,6 +111,7 @@
     resources :splits, only: [:show] do
       resource :details, only: [:edit, :update], controller: 'split_details'
       resource :split_config, only: [:new, :create]
+      resources :assignments, only: [:index], controller: 'split_assignments'
       resources :bulk_assignments, only: [:new, :create]
       resources :decisions, only: [:new, :create]
       resources :variants, only: [] do

spec/support/pages/admin/split_assignments_page.rb

@@ -0,0 +1,5 @@
+class AdminSplitAssignmentsPage < SitePrism::Page
+  set_url "/admin/splits/{split_id}/assignments"
+
+  elements :assignments, ".AdminSplitAssignments--index table tbody tr"
+end

spec/system/admin_split_assignments_spec.rb

@@ -0,0 +1,41 @@
+require 'rails_helper'
+
+RSpec.describe 'bulk assign flow' do
+  let(:split_page) { app.admin_split_show_page }
+  let(:assignments_page) { app.admin_split_assignments_page }
+
+  let(:split) { FactoryBot.create(:split) }
+  let(:assignment_count) { 3 }
+  let!(:assignments) do
+    Assignment.transaction do
+      identifiers = FactoryBot.create_list(:identifier, assignment_count)
+      identifiers.map(&:visitor).map { |visitor| FactoryBot.create(:assignment, split:, visitor:) }
+    end
+  end
+
+  before do
+    login
+  end
+
+  it 'allows admins to view assignments' do
+    split_page.load split_id: split.id
+
+    expect(split_page.population_count).to have_content "3"
+    split_page.population_count.click
+
+    expect(assignments_page.assignments.length).to eq 3
+  end
+
+  context 'with too many assignments' do
+    let(:assignment_count) { 1005 }
+
+    it 'shows a limited number of assignments' do
+      split_page.load split_id: split.id
+
+      expect(split_page.population_count).to have_content "1005"
+      split_page.population_count.click
+
+      expect(assignments_page.assignments.length).to eq 1000
+    end
+  end
+end