Encapsulate knowledge of type objects on `ActiveRecord::Result`

Attempting to reduce the number of places that care about the details of
how type casting occurs. We remove the type casting of the primary key
in `JoinDependecy`, rather than encapsulating it. It was originally
added for consistency with
https://github.com/rails/rails/commit/40898c8c19fa04442fc5f8fb5daf3a8bdb9a1e03#diff-06059df8d3dee3101718fb2c01151ad0R211,
but that conditional was later removed in
https://github.com/rails/rails/commit/d7ddaa530fd1b94e22d745cbaf2e8a5a34ee9734.

What is important is that the same row twice will have the same value
for the primary key, which it will.

1 files changed, 40 insertions, 4 deletions

diff --git a/activerecord/test/cases/result_test.rb b/activerecord/test/cases/result_test.rb
index 2131b32a0c..d6decafad9 100644
--- a/activerecord/test/cases/result_test.rb
+++ b/activerecord/test/cases/result_test.rb
@@ -10,7 +10,7 @@ module ActiveRecord
       ])
     end
 
-    def test_to_hash_returns_row_hashes
+    test "to_hash returns row_hashes" do
       assert_equal [
         {'col_1' => 'row 1 col 1', 'col_2' => 'row 1 col 2'},
         {'col_1' => 'row 2 col 1', 'col_2' => 'row 2 col 2'},
@@ -18,13 +18,13 @@ module ActiveRecord
       ], result.to_hash
     end
 
-    def test_each_with_block_returns_row_hashes
+    test "each with block returns row hashes" do
       result.each do |row|
         assert_equal ['col_1', 'col_2'], row.keys
       end
     end
 
-    def test_each_without_block_returns_an_enumerator
+    test "each without block returns an enumerator" do
       result.each.with_index do |row, index|
         assert_equal ['col_1', 'col_2'], row.keys
         assert_kind_of Integer, index
@@ -32,9 +32,45 @@ module ActiveRecord
     end
 
     if Enumerator.method_defined? :size
-      def test_each_without_block_returns_a_sized_enumerator
+      test "each without block returns a sized enumerator" do
         assert_equal 3, result.each.size
       end
     end
+
+    test "cast_values returns rows after type casting" do
+      values = [["1.1", "2.2"], ["3.3", "4.4"]]
+      columns = ["col1", "col2"]
+      types = { "col1" => Type::Integer.new, "col2" => Type::Float.new }
+      result = Result.new(columns, values, types)
+
+      assert_equal [[1, 2.2], [3, 4.4]], result.cast_values
+    end
+
+    test "cast_values uses identity type for unknown types" do
+      values = [["1.1", "2.2"], ["3.3", "4.4"]]
+      columns = ["col1", "col2"]
+      types = { "col1" => Type::Integer.new }
+      result = Result.new(columns, values, types)
+
+      assert_equal [[1, "2.2"], [3, "4.4"]], result.cast_values
+    end
+
+    test "cast_values returns single dimensional array if single column" do
+      values = [["1.1"], ["3.3"]]
+      columns = ["col1"]
+      types = { "col1" => Type::Integer.new }
+      result = Result.new(columns, values, types)
+
+      assert_equal [1, 3], result.cast_values
+    end
+
+    test "cast_values can receive types to use instead" do
+      values = [["1.1", "2.2"], ["3.3", "4.4"]]
+      columns = ["col1", "col2"]
+      types = { "col1" => Type::Integer.new, "col2" => Type::Float.new }
+      result = Result.new(columns, values, types)
+
+      assert_equal [[1.1, 2.2], [3.3, 4.4]], result.cast_values("col1" => Type::Float.new)
+    end
   end
 end