Ask the model for its DOM name instead of approximating it

CHANGELOG.md

@@ -6,6 +6,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+ - `attributes_table_selector`, `form_selector` and `table_selector` now ask the
+   model for its DOM name (`model_name.singular` / `.plural`, the same source
+   Arbre and ActiveAdmin use) instead of `gsub(' ', '_')`. A namespaced name
+   previously kept its `::` and produced `div.attributes_table.billing::employee`
+   — not a selector, so it aborted the example instead of failing it.
+   `table_selector` also accepts a model class now.
+
 ### Changed
  - tested against Ruby 3.3, 3.4, 4.0 and Rails 8.0, 8.1 (EOL Rails 7.2 dropped from CI)
 

README.md

@@ -55,17 +55,17 @@ RSpec.describe 'Users', js: true do
 
     within_table_for('users') do
       expect(page).to have_table_row(count: 2)
-      expect(page).to have_table_cell('John Doe')
+      expect(page).to have_table_cell(text: 'John Doe')
 
       within_table_row(id: john.id) do
-        expect(page).to have_table_cell('John Doe', row_id: john.id)
-        expect(page).to have_table_cell('John Doe', row_id: john.id, col_name: 'Full Name')
-        expect(page).to_not have_table_cell('John Doe', row_id: john.id, col_name: 'Id')
+        expect(page).to have_table_cell(text: 'John Doe')
+        expect(page).to have_table_cell(text: 'John Doe', column: 'Full Name')
+        expect(page).to_not have_table_cell(text: 'John Doe', column: 'Id')
       end
 
       within_table_row(id: jane.id) do
-        expect(page).to_not have_table_cell('John Doe')
-        expect(page).to_not have_table_cell('John Doe', col_name: 'Full Name')
+        expect(page).to_not have_table_cell(text: 'John Doe')
+        expect(page).to_not have_table_cell(text: 'John Doe', column: 'Full Name')
       end
     end
   end

lib/capybara/active_admin/selectors/table.rb

@@ -10,8 +10,12 @@ module Table
         def table_selector(resource_name = nil)
           return 'table.index_table' if resource_name.nil?
 
-          resource_name = resource_name.to_s.gsub(' ', '_').pluralize.downcase
-          "table#index_table_#{resource_name}"
+          # NOTE: ActiveAdmin builds this id from the registered resource name
+          # (`active_admin_config.resource_name.plural`, index_as_table.rb:240),
+          # which `register Model, as: 'Other Name'` detaches from the model.
+          # A class can only ever yield the model's own name, so a renamed
+          # resource has to be addressed by the name it was registered under.
+          "table#index_table_#{Util.parse_model_name(resource_name, singular: false)}"
         end
 
         # @param record_id [String, Integer, nil] record ID.

lib/capybara/active_admin/util.rb

@@ -5,12 +5,27 @@ module ActiveAdmin
     module Util
       # Common pure utility functions
 
+      # Arbre derives a record's DOM name from
+      # `record.class.model_name.singular`, falling back to
+      # `name.underscore.gsub('/', '_')` (arbre html/tag.rb:164-168). Ask the
+      # model the same question instead of approximating it: `gsub(' ', '_')`
+      # leaves the `::` of a namespaced name in place, and
+      # `div.attributes_table.billing::employee` is not a selector -- Nokogiri
+      # raises `SyntaxError` on it with nothing pointing at the cause.
       def parse_model_name(model_name, singular: true)
         return if model_name.nil?
 
-        model_name = model_name.model_name.singular if model_name.is_a?(Class)
-        model_name = model_name.to_s.gsub(' ', '_').downcase
-        singular ? model_name.singularize : model_name.pluralize
+        if model_name.is_a?(Class) && model_name.respond_to?(:model_name)
+          name = model_name.model_name
+          return singular ? name.singular : name.plural
+        end
+
+        dom_model_name(model_name.is_a?(Class) ? model_name.name : model_name, singular: singular)
+      end
+
+      def dom_model_name(name, singular: true)
+        name = name.to_s.underscore.tr('/', '_').tr(' ', '_')
+        singular ? name.singularize : name.pluralize
       end
 
       # ActiveAdmin derives the CSS class of a row or column from the
@@ -28,7 +43,7 @@ def options_with_text(text, options = {})
         options.except(:exact).merge(key => text)
       end
 
-      module_function :parse_model_name, :css_class_for_label, :options_with_text
+      module_function :parse_model_name, :dom_model_name, :css_class_for_label, :options_with_text
     end
   end
 end

spec/lib/selectors/attributes_table_spec.rb

@@ -5,6 +5,21 @@
     Class.new { include Capybara::ActiveAdmin::Selectors::AttributesTable }.new
   end
 
+  describe '#attributes_table_selector' do
+    it 'asks a model class for its DOM name' do
+      expect(helper.attributes_table_selector(model: Billing::Employee))
+        .to eq('div.attributes_table.billing_employee')
+    end
+
+    # Arbre uses `model_name.singular` — underscore, then '/' -> '_'. The
+    # previous `gsub(' ', '_')` kept the '::' and Nokogiri raised on
+    # `div.attributes_table.billing::employee`.
+    it 'underscores a namespaced name given as a string' do
+      expect(helper.attributes_table_selector(model: 'Billing::Employee'))
+        .to eq('div.attributes_table.billing_employee')
+    end
+  end
+
   describe '#attributes_row_selector' do
     it 'returns a generic row selector when no label given' do
       expect(helper.attributes_row_selector).to eq('tr.row > td')

spec/lib/selectors/table_spec.rb

@@ -42,6 +42,27 @@
     end
   end
 
+  describe '#table_selector' do
+    it 'returns the generic selector when no resource name given' do
+      expect(helper.table_selector).to eq('table.index_table')
+    end
+
+    it 'builds the id from a registered resource name' do
+      expect(helper.table_selector('Business Employee')).to eq('table#index_table_business_employees')
+    end
+
+    # ActiveAdmin's id comes from `resource_name.plural`, which underscores the
+    # namespace. `gsub(' ', '_')` left the `::` in place, and Nokogiri raises
+    # on `table#index_table_billing::employees`.
+    it 'underscores a namespaced name instead of leaving ::' do
+      expect(helper.table_selector('Billing::Employee')).to eq('table#index_table_billing_employees')
+    end
+
+    it 'asks a model class for its own plural' do
+      expect(helper.table_selector(Billing::Employee)).to eq('table#index_table_billing_employees')
+    end
+  end
+
   describe '#table_cell_selector' do
     it 'returns generic selector when column is nil' do
       expect(helper.table_cell_selector).to eq('td.col')

spec/system/namespaced_model_names_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+# ActiveAdmin and Arbre derive these DOM names from the model and the
+# registered resource name. Asserting them against a real rendered page is the
+# only way to catch a derivation that merely looks plausible: the previous one
+# produced `billing::employee`, which is not a selector at all.
+RSpec.describe 'DOM names of a namespaced resource', type: :feature, js: true do
+  let!(:record) { Billing::Employee.create!(full_name: 'John Doe', salary: 100) }
+
+  it 'finds the attributes table from the model class and from its name' do
+    visit admin_business_employee_path(record.id)
+
+    expect(page).to have_attributes_table(model: Billing::Employee)
+    expect(page).to have_attributes_table(model: 'Billing::Employee')
+  end
+
+  it 'finds the index table by the name the resource was registered under' do
+    visit admin_business_employees_path
+
+    expect(page).to have_table(resource_name: 'Business Employee')
+  end
+end