3 files changed, 10 insertions, 15 deletions
diff --git a/activesupport/test/core_ext/object/json_test.rb b/activesupport/test/core_ext/object/json_test.rb
deleted file mode 100644
index d3d31530df..0000000000
--- a/activesupport/test/core_ext/object/json_test.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-require 'abstract_unit'
-
-class JsonTest < ActiveSupport::TestCase
-  # See activesupport/test/json/encoding_test.rb for JSON encoding tests
-
-  def test_deprecated_require_to_json_rb
-    assert_deprecated { require 'active_support/core_ext/object/to_json' }
-  end
-end
diff --git a/activesupport/test/core_ext/object/to_query_test.rb b/activesupport/test/core_ext/object/to_query_test.rb
index f887a9e613..7457c4655a 100644
--- a/activesupport/test/core_ext/object/to_query_test.rb
+++ b/activesupport/test/core_ext/object/to_query_test.rb
@@ -49,13 +49,15 @@ class ToQueryTest < ActiveSupport::TestCase
   def test_nested_empty_hash
     assert_equal '',
       {}.to_query
-    assert_query_equal 'a=1&b%5Bc%5D=3&b%5Bd%5D=',
+    assert_query_equal 'a=1&b%5Bc%5D=3',
       { a: 1, b: { c: 3, d: {} } }
+    assert_query_equal '',
+      { a: {b: {c: {}}} }
     assert_query_equal 'b%5Bc%5D=false&b%5Be%5D=&b%5Bf%5D=&p=12',
       { p: 12, b: { c: false, e: nil, f: '' } }
-    assert_query_equal 'b%5Bc%5D=3&b%5Bf%5D=&b%5Bk%5D=',
+    assert_query_equal 'b%5Bc%5D=3&b%5Bf%5D=',
       { b: { c: 3, k: {}, f: '' } }
-    assert_query_equal 'a%5B%5D=&b=3',
+    assert_query_equal 'b=3',
       {a: [], b: 3}
   end
 
diff --git a/activesupport/test/inflector_test_cases.rb b/activesupport/test/inflector_test_cases.rb
index dd03a61176..b556da0046 100644
--- a/activesupport/test/inflector_test_cases.rb
+++ b/activesupport/test/inflector_test_cases.rb
@@ -208,9 +208,11 @@ module InflectorTestCases
   }
 
   UnderscoreToHuman = {
-    "employee_salary" => "Employee salary",
-    "employee_id"     => "Employee",
-    "underground"     => "Underground"
+    'employee_salary' => 'Employee salary',
+    'employee_id'     => 'Employee',
+    'underground'     => 'Underground',
+    '_id'             => 'Id',
+    '_external_id'    => 'External'
   }
 
   UnderscoreToHumanWithoutCapitalize = {