From 1a20683f0919680de4875c8097e7114a529aeb88 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Juanjo=20Baza=CC=81n?= Date: Wed, 11 Apr 2012 15:24:23 +0200 Subject: [PATCH] Override AR::Relation methods in NullRelation. So a NullRelation (Relation#none) is chainable with database methods. --- .../lib/active_record/null_relation.rb | 53 +++++++++++++++++++ activerecord/test/cases/relations_test.rb | 33 ++++++++++++ 2 files changed, 86 insertions(+) diff --git a/activerecord/lib/active_record/null_relation.rb b/activerecord/lib/active_record/null_relation.rb index 60c37ac2b7..c2d3eeb8ce 100644 --- a/activerecord/lib/active_record/null_relation.rb +++ b/activerecord/lib/active_record/null_relation.rb @@ -6,5 +6,58 @@ class NullRelation < Relation def exec_queries @records = [] end + + def pluck(column_name) + [] + end + + def delete_all(conditions = nil) + 0 + end + + def update_all(updates, conditions = nil, options = {}) + 0 + end + + def delete(id_or_array) + 0 + end + + def size + 0 + end + + def empty? + true + end + + def any? + false + end + + def many? + false + end + + def to_sql + @to_sql ||= "" + end + + def where_values_hash + {} + end + + def count + 0 + end + + def calculate(operation, column_name, options = {}) + nil + end + + def exists?(id = false) + false + end + end end \ No newline at end of file diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb index 25eb7c1672..5e938968a3 100644 --- a/activerecord/test/cases/relations_test.rb +++ b/activerecord/test/cases/relations_test.rb @@ -219,6 +219,7 @@ def test_none assert_no_queries do assert_equal [], Developer.none assert_equal [], Developer.scoped.none + assert Developer.none.is_a?(ActiveRecord::NullRelation) end end @@ -228,6 +229,38 @@ def test_none_chainable end end + def test_none_chained_to_methods_firing_queries_straight_to_db + assert_no_queries do + assert_equal [], Developer.none.pluck(:id) # => uses select_all + assert_equal 0, Developer.none.delete_all + assert_equal 0, Developer.none.update_all(:name => 'David') + assert_equal 0, Developer.none.delete(1) + assert_equal false, Developer.none.exists?(1) + end + end + + def test_null_relation_content_size_methods + assert_no_queries do + assert_equal 0, Developer.none.size + assert_equal 0, Developer.none.count + assert_equal true, Developer.none.empty? + assert_equal false, Developer.none.any? + assert_equal false, Developer.none.many? + end + end + + def test_null_relation_calculations_methods + assert_no_queries do + assert_equal 0, Developer.none.count + assert_equal nil, Developer.none.calculate(:average, 'salary') + end + end + + def test_null_relation_metadata_methods + assert_equal "", Developer.none.to_sql + assert_equal({}, Developer.none.where_values_hash) + end + def test_joins_with_nil_argument assert_nothing_raised { DependentFirm.joins(nil).first } end -- GitLab