Fix deprecated ActiveRecord connection checkout

lib/rails_erd/diagram/tbls.rb

@@ -86,9 +86,11 @@ def column_payload(attr)
       end
 
       def indexes_payload(model)
-        return [] unless model.connection.respond_to?(:indexes)
+        indexes = model.connection_pool.with_connection do |connection|
+          connection.respond_to?(:indexes) ? connection.indexes(model.table_name) : []
+        end
 
-        model.connection.indexes(model.table_name).map do |idx|
+        indexes.map do |idx|
           columns = Array(idx.columns).map(&:to_s)
           {
             name: idx.name,

lib/rails_erd/domain/attribute.rb

@@ -163,7 +163,9 @@ def limit_description # @private :nodoc:
       private
 
       def native_type
-        @model.connection.native_database_types[type] or {}
+        @model.connection_pool.with_connection do |connection|
+          connection.native_database_types[type] or {}
+        end
       end
     end
   end

test/test_helper.rb

@@ -101,6 +101,23 @@ def create_models(*names)
     end
   end
 
+  # Rails 7.2+ can forbid the implicit permanent checkout done by
+  # ActiveRecord::Base.connection. The check only applies while the thread holds
+  # no leased connection, so release the one schema setup leased. Earlier
+  # versions have no such setting, so the block runs unchanged there.
+  def with_permanent_connection_checkout_disallowed
+    return yield unless ActiveRecord.respond_to?(:permanent_connection_checkout=)
+
+    previous = ActiveRecord.permanent_connection_checkout
+    ActiveRecord::Base.connection_pool.release_connection
+    ActiveRecord.permanent_connection_checkout = :disallowed
+    begin
+      yield
+    ensure
+      ActiveRecord.permanent_connection_checkout = previous
+    end
+  end
+
   def collect_stdout
     stdout = $stdout
     $stdout = StringIO.new

test/unit/attribute_test.rb

@@ -208,6 +208,17 @@ def create_attribute(model, name)
     end
   end
 
+  test "type_description should use a scoped connection when permanent connection checkout is disallowed" do
+    with_native_limit :string, 456 do
+      create_model "Foo"
+      add_column :foos, :my_str, :string, :limit => 255
+      attribute = create_attribute(Foo, "my_str")
+      with_permanent_connection_checkout_disallowed do
+        assert_equal "string (255)", attribute.type_description
+      end
+    end
+  end
+
   test "type_description should append hair space and low asterisk if field is mandatory" do
     create_model "Foo", :a => :integer do
       validates_presence_of :a

test/unit/graphviz_test.rb

@@ -52,6 +52,15 @@ def find_dot_edge_styles(diagram)
     assert result.end_with?(".svg"), "Expected filename to end with .svg, got: #{result}"
   end
 
+  test "create should write a pdf when permanent connection checkout is disallowed" do
+    create_model "Foo", :name => :string
+    result = with_permanent_connection_checkout_disallowed do
+      Diagram::Graphviz.create(:filetype => :pdf)
+    end
+    assert result.end_with?(".pdf"), "Expected filename to end with .pdf, got: #{result}"
+    assert_equal "%PDF-", File.binread(result, 5)
+  end
+
   test "rank direction should be tb for horizontal orientation" do
     create_simple_domain
     assert_equal '"TB"', diagram(:orientation => "horizontal").graph[:rankdir].to_s

test/unit/tbls_test.rb

@@ -141,6 +141,20 @@ def constraint(table, type)
     assert_equal %w[authors books], fk_targets
   end
 
+  test "indexes are emitted when permanent connection checkout is disallowed" do
+    create_model "Widget", name: :string
+    ActiveRecord::Base.connection.add_index :widgets, :name, unique: true, name: "index_widgets_on_name"
+
+    widgets = with_permanent_connection_checkout_disallowed { table(payload, "widgets") }
+
+    assert_equal [{
+      name: "index_widgets_on_name",
+      def: "CREATE UNIQUE INDEX index_widgets_on_name ON widgets (name)",
+      table: "widgets",
+      columns: ["name"],
+    }], widgets[:indexes]
+  end
+
   # Schema-level payload =====================================================
   test "top-level payload has a name and a tables array" do
     create_simple_domain