add support for counting grouped collections (#51)

lib/pagy/backend.rb

@@ -16,9 +16,10 @@ def pagy(collection, vars={})
 
  # Sub-method called only by #pagy: here for easy customization of variables by overriding
  def pagy_get_vars(collection, vars)
- # Return the merged variables to initialize the Pagy object
- { count: collection.count(:all), # works with AR, but may not work with other ORMs
- page: params[vars[:page_param]||VARS[:page_param]] }.merge!(vars)
+ count = collection.count(:all)
+ count = count.count if count.respond_to?(:count) # e.g. AR .group returns an OrderdHash that responds to #count
+ # return the merged variables to initialize the pagy object
+ { count: count, page: params[vars[:page_param] || VARS[:page_param]] }.merge!(vars)
  end
 
  # Sub-method called only by #pagy: here for easy customization of record-extraction by overriding

test/pagy/backend_test.rb

@@ -4,7 +4,6 @@
 
 describe Pagy::Backend do
 
-
  let(:backend) { TestController.new }
 
  describe "#pagy" do
@@ -66,6 +65,20 @@ def test_pagy_get_vars_with_vars
  assert_equal('X', merged[:link_extra])
  end
 
+ def test_pagy_get_vars_with_grouped_collection
+ @collection = GroupedCollection.new((1..1000).to_a)
+ vars = {page: 2, items: 10, link_extra: 'X'}
+ merged = backend.send :pagy_get_vars, @collection, vars
+ assert_includes(merged.keys, :count)
+ assert_includes(merged.keys, :page)
+ assert_includes(merged.keys, :items)
+ assert_includes(merged.keys, :link_extra)
+ assert_equal(1000, merged[:count])
+ assert_equal(2, merged[:page])
+ assert_equal(10, merged[:items])
+ assert_equal('X', merged[:link_extra])
+ end
+
  end
 
  describe "#pagy_get_items" do

test/test_helper/backend.rb

@@ -30,3 +30,11 @@ def count(*_)
  end
 
 end
+
+class GroupedCollection < TestCollection
+
+ def count(*_)
+ @collection.map { |value| [value, value + 1] }.to_h
+ end
+
+end