diff --git a/Gemfile b/Gemfile
index 20cc48a567e..b628640f9eb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,11 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 gemspec
 
-gem "minitest", ">= 5.15.0", "< 5.16.0"
+if RUBY_VERSION < "3"
+  gem "minitest", ">= 5.15.0", "< 5.16"
+else
+  gem "minitest", ">= 5.15.0"
+end
 
 # We need a newish Rake since Active Job sets its test tasks' descriptions.
 gem "rake", ">= 11.1"
diff --git a/Gemfile.lock b/Gemfile.lock
index 91a71fb8870..156557e1a87 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -322,7 +322,7 @@ GEM
     mini_magick (4.11.0)
     mini_mime (1.1.2)
     mini_portile2 (2.8.0)
-    minitest (5.15.0)
+    minitest (5.16.1)
     minitest-bisect (1.5.1)
       minitest-server (~> 1.0)
       path_expander (~> 1.1)
@@ -586,7 +586,7 @@ DEPENDENCIES
   kindlerb (~> 1.2.0)
   libxml-ruby
   listen (~> 3.3)
-  minitest (>= 5.15.0, < 5.16.0)
+  minitest (>= 5.15.0)
   minitest-bisect
   minitest-ci
   minitest-retry
diff --git a/actionpack/test/controller/integration_test.rb b/actionpack/test/controller/integration_test.rb
index 2fcd56e71a5..99f92b3c3d0 100644
--- a/actionpack/test/controller/integration_test.rb
+++ b/actionpack/test/controller/integration_test.rb
@@ -36,91 +36,91 @@ class SessionTest < ActiveSupport::TestCase
   def test_get
     path = "/index"; params = "blah"; headers = { location: "blah" }
 
-    assert_called_with @session, :process, [:get, path, params: params, headers: headers] do
+    assert_called_with @session, :process, [:get, path], params: params, headers: headers do
       @session.get(path, params: params, headers: headers)
     end
   end
 
   def test_get_with_env_and_headers
     path = "/index"; params = "blah"; headers = { location: "blah" }; env = { "HTTP_X_REQUESTED_WITH" => "XMLHttpRequest" }
-    assert_called_with @session, :process, [:get, path, params: params, headers: headers, env: env] do
+    assert_called_with @session, :process, [:get, path], params: params, headers: headers, env: env do
       @session.get(path, params: params, headers: headers, env: env)
     end
   end
 
   def test_post
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:post, path, params: params, headers: headers] do
+    assert_called_with @session, :process, [:post, path], params: params, headers: headers do
       @session.post(path, params: params, headers: headers)
     end
   end
 
   def test_patch
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:patch, path, params: params, headers: headers] do
+    assert_called_with @session, :process, [:patch, path], params: params, headers: headers do
       @session.patch(path, params: params, headers: headers)
     end
   end
 
   def test_put
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:put, path, params: params, headers: headers] do
+    assert_called_with @session, :process, [:put, path], params: params, headers: headers do
       @session.put(path, params: params, headers: headers)
     end
   end
 
   def test_delete
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:delete, path, params: params, headers: headers] do
+    assert_called_with @session, :process, [:delete, path], params: params, headers: headers do
       @session.delete(path, params: params, headers: headers)
     end
   end
 
   def test_head
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:head, path, params: params, headers: headers] do
+    assert_called_with @session, :process, [:head, path], params: params, headers: headers do
       @session.head(path, params: params, headers: headers)
     end
   end
 
   def test_xml_http_request_get
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:get, path, params: params, headers: headers, xhr: true] do
+    assert_called_with @session, :process, [:get, path], params: params, headers: headers, xhr: true do
       @session.get(path, params: params, headers: headers, xhr: true)
     end
   end
 
   def test_xml_http_request_post
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:post, path, params: params, headers: headers, xhr: true] do
+    assert_called_with @session, :process, [:post, path], params: params, headers: headers, xhr: true do
       @session.post(path, params: params, headers: headers, xhr: true)
     end
   end
 
   def test_xml_http_request_patch
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:patch, path, params: params, headers: headers, xhr: true] do
+    assert_called_with @session, :process, [:patch, path], params: params, headers: headers, xhr: true do
       @session.patch(path, params: params, headers: headers, xhr: true)
     end
   end
 
   def test_xml_http_request_put
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:put, path, params: params, headers: headers, xhr: true] do
+    assert_called_with @session, :process, [:put, path], params: params, headers: headers, xhr: true do
       @session.put(path, params: params, headers: headers, xhr: true)
     end
   end
 
   def test_xml_http_request_delete
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:delete, path, params: params, headers: headers, xhr: true] do
+    assert_called_with @session, :process, [:delete, path], params: params, headers: headers, xhr: true do
       @session.delete(path, params: params, headers: headers, xhr: true)
     end
   end
 
   def test_xml_http_request_head
     path = "/index"; params = "blah"; headers = { location: "blah" }
-    assert_called_with @session, :process, [:head, path, params: params, headers: headers, xhr: true] do
+    assert_called_with @session, :process, [:head, path], params: params, headers: headers, xhr: true do
       @session.head(path, params: params, headers: headers, xhr: true)
     end
   end
diff --git a/actionview/test/template/date_helper_i18n_test.rb b/actionview/test/template/date_helper_i18n_test.rb
index 2f098e2f515..819d0d0ac20 100644
--- a/actionview/test/template/date_helper_i18n_test.rb
+++ b/actionview/test/template/date_helper_i18n_test.rb
@@ -49,7 +49,7 @@ class DateHelperDistanceOfTimeInWordsI18nTests < ActiveSupport::TestCase
   end
 
   def test_time_ago_in_words_passes_locale
-    assert_called_with(I18n, :t, [:less_than_x_minutes, scope: :'datetime.distance_in_words', count: 1, locale: "ru"]) do
+    assert_called_with(I18n, :t, [:less_than_x_minutes], scope: :'datetime.distance_in_words', count: 1, locale: "ru") do
       time_ago_in_words(15.seconds.ago, locale: "ru")
     end
   end
@@ -84,7 +84,7 @@ class DateHelperDistanceOfTimeInWordsI18nTests < ActiveSupport::TestCase
     options = { locale: "en", scope: :'datetime.distance_in_words' }.merge!(expected_options)
     options[:count] = count if count
 
-    assert_called_with(I18n, :t, [key, options]) do
+    assert_called_with(I18n, :t, [key], **options) do
       distance_of_time_in_words(@from, to, passed_options.merge(locale: "en"))
     end
   end
@@ -103,13 +103,13 @@ class DateHelperSelectTagsI18nTests < ActiveSupport::TestCase
   end
 
   def test_select_month_translates_monthnames
-    assert_called_with(I18n, :translate, [:'date.month_names', locale: "en"], returns: Date::MONTHNAMES) do
+    assert_called_with(I18n, :translate, [:'date.month_names'], returns: Date::MONTHNAMES, locale: "en") do
       select_month(8, locale: "en")
     end
   end
 
   def test_select_month_given_use_short_month_option_translates_abbr_monthnames
-    assert_called_with(I18n, :translate, [:'date.abbr_month_names', locale: "en"], returns: Date::ABBR_MONTHNAMES) do
+    assert_called_with(I18n, :translate, [:'date.abbr_month_names'], returns: Date::ABBR_MONTHNAMES, locale: "en") do
       select_month(8, locale: "en", use_short_month: true)
     end
   end
@@ -147,8 +147,8 @@ class DateHelperSelectTagsI18nTests < ActiveSupport::TestCase
 
   def test_date_or_time_select_given_no_order_options_translates_order
     mock = Minitest::Mock.new
-    mock.expect(:call, ["year", "month", "day"], [:'date.order', { locale: "en", default: [] }])
-    mock.expect(:call, [], [:'date.month_names', { locale: "en" }])
+    expect_called_with(mock, [:'date.order'], locale: "en", default: [], returns: ["year", "month", "day"])
+    expect_called_with(mock, [:'date.month_names'], locale: "en", returns: [])
 
     I18n.stub(:translate, mock) do
       datetime_select("post", "updated_at", locale: "en")
@@ -158,7 +158,7 @@ class DateHelperSelectTagsI18nTests < ActiveSupport::TestCase
   end
 
   def test_date_or_time_select_given_invalid_order
-    assert_called_with(I18n, :translate, [:'date.order', locale: "en", default: []], returns: %w(invalid month day)) do
+    assert_called_with(I18n, :translate, [:'date.order'], returns: %w(invalid month day), locale: "en", default: []) do
       assert_raise StandardError do
         datetime_select("post", "updated_at", locale: "en")
       end
@@ -167,8 +167,8 @@ class DateHelperSelectTagsI18nTests < ActiveSupport::TestCase
 
   def test_date_or_time_select_given_symbol_keys
     mock = Minitest::Mock.new
-    mock.expect(:call, [:year, :month, :day], [:'date.order', { locale: "en", default: [] }])
-    mock.expect(:call, [], [:'date.month_names', { locale: "en" }])
+    expect_called_with(mock, [:'date.order'], locale: "en", default: [], returns: [:year, :month, :day])
+    expect_called_with(mock, [:'date.month_names'], locale: "en", returns: [])
 
     I18n.stub(:translate, mock) do
       datetime_select("post", "updated_at", locale: "en")
diff --git a/actionview/test/template/form_helper/form_with_test.rb b/actionview/test/template/form_helper/form_with_test.rb
index 00e6ca42ea4..b3d6d59cd3a 100644
--- a/actionview/test/template/form_helper/form_with_test.rb
+++ b/actionview/test/template/form_helper/form_with_test.rb
@@ -1768,7 +1768,7 @@ class FormWithActsLikeFormForTest < FormWithTest
 
     mock = Minitest::Mock.new
     @post.comments.each do
-      mock.expect(:call, "body", ["post.comments.body", default: [:"comment.body", ""], scope: "helpers.label"])
+      expect_called_with(mock, ["post.comments.body"], default: [:"comment.body", ""], scope: "helpers.label", returns: "body")
     end
 
     I18n.stub(:t, mock) do
diff --git a/actionview/test/template/form_helper_test.rb b/actionview/test/template/form_helper_test.rb
index 8560be2770c..d8924d3e650 100644
--- a/actionview/test/template/form_helper_test.rb
+++ b/actionview/test/template/form_helper_test.rb
@@ -3302,7 +3302,7 @@ class FormHelperTest < ActionView::TestCase
 
     mock = Minitest::Mock.new
     @post.comments.each do
-      mock.expect(:call, "body", ["post.comments.body", default: [:"comment.body", ""], scope: "helpers.label"])
+      expect_called_with(mock, ["post.comments.body"], default: [:"comment.body", ""], scope: "helpers.label", returns: "body")
     end
 
     I18n.stub(:t, mock) do
diff --git a/actionview/test/template/form_options_helper_i18n_test.rb b/actionview/test/template/form_options_helper_i18n_test.rb
index 21295fa547d..3dc625b8ac1 100644
--- a/actionview/test/template/form_options_helper_i18n_test.rb
+++ b/actionview/test/template/form_options_helper_i18n_test.rb
@@ -16,7 +16,7 @@ class FormOptionsHelperI18nTests < ActionView::TestCase
   end
 
   def test_select_with_prompt_true_translates_prompt_message
-    assert_called_with(I18n, :translate, ["helpers.select.prompt", { default: "Please select" }]) do
+    assert_called_with(I18n, :translate, ["helpers.select.prompt"], default: "Please select") do
       select("post", "category", [], prompt: true)
     end
   end
diff --git a/actionview/test/template/translation_helper_test.rb b/actionview/test/template/translation_helper_test.rb
index 9ed034113d0..b9da9174a51 100644
--- a/actionview/test/template/translation_helper_test.rb
+++ b/actionview/test/template/translation_helper_test.rb
@@ -65,7 +65,7 @@ class TranslationHelperTest < ActiveSupport::TestCase
 
   def test_delegates_localize_to_i18n
     @time = Time.utc(2008, 7, 8, 12, 18, 38)
-    assert_called_with(I18n, :localize, [@time, locale: "en"]) do
+    assert_called_with(I18n, :localize, [@time], locale: "en") do
       localize @time, locale: "en"
     end
     assert_equal "Tue, 08 Jul 2008 12:18:38 +0000", localize(@time, locale: "en")
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index 0267da5116b..772f421f2c8 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -995,7 +995,7 @@ class TransactionalFixturesOnConnectionNotification < ActiveRecord::TestCase
       def lock_thread=(lock_thread); end
     end.new
 
-    assert_called_with(connection, :begin_transaction, [joinable: false, _lazy: false]) do
+    assert_called_with(connection, :begin_transaction, [], joinable: false, _lazy: false) do
       fire_connection_notification(connection)
     end
   end
@@ -1035,14 +1035,14 @@ class TransactionalFixturesOnConnectionNotification < ActiveRecord::TestCase
       def lock_thread=(lock_thread); end
     end.new
 
-    assert_called_with(connection, :begin_transaction, [joinable: false, _lazy: false]) do
+    assert_called_with(connection, :begin_transaction, [], joinable: false, _lazy: false) do
       fire_connection_notification(connection, shard: :shard_two)
     end
   end
 
   private
     def fire_connection_notification(connection, shard: ActiveRecord::Base.default_shard)
-      assert_called_with(ActiveRecord::Base.connection_handler, :retrieve_connection, ["book", { shard: shard }], returns: connection) do
+      assert_called_with(ActiveRecord::Base.connection_handler, :retrieve_connection, ["book"], returns: connection, shard: shard) do
         message_bus = ActiveSupport::Notifications.instrumenter
         payload = {
           spec_name: "book",
diff --git a/activerecord/test/cases/migration/change_table_test.rb b/activerecord/test/cases/migration/change_table_test.rb
index 5cf6493e52b..620319b3865 100644
--- a/activerecord/test/cases/migration/change_table_test.rb
+++ b/activerecord/test/cases/migration/change_table_test.rb
@@ -17,117 +17,131 @@ module ActiveRecord
         yield ActiveRecord::Base.connection.update_table_definition(:delete_me, @connection)
       end
 
+      if Minitest::Mock.instance_method(:expect).parameters.map(&:first).include?(:keyrest)
+        def expect(method, returns, args, **kwargs)
+          @connection.expect(method, returns, args, **kwargs)
+        end
+      else
+        def expect(method, returns, args, **kwargs)
+          if !kwargs.empty?
+            @connection.expect(method, returns, [*args, kwargs])
+          else
+            @connection.expect(method, returns, args)
+          end
+        end
+      end
+
       def test_references_column_type_adds_id
         with_change_table do |t|
-          @connection.expect :add_reference, nil, [:delete_me, :customer]
+          expect :add_reference, nil, [:delete_me, :customer]
           t.references :customer
         end
       end
 
       def test_remove_references_column_type_removes_id
         with_change_table do |t|
-          @connection.expect :remove_reference, nil, [:delete_me, :customer]
+          expect :remove_reference, nil, [:delete_me, :customer]
           t.remove_references :customer
         end
       end
 
       def test_add_belongs_to_works_like_add_references
         with_change_table do |t|
-          @connection.expect :add_reference, nil, [:delete_me, :customer]
+          expect :add_reference, nil, [:delete_me, :customer]
           t.belongs_to :customer
         end
       end
 
       def test_remove_belongs_to_works_like_remove_references
         with_change_table do |t|
-          @connection.expect :remove_reference, nil, [:delete_me, :customer]
+          expect :remove_reference, nil, [:delete_me, :customer]
           t.remove_belongs_to :customer
         end
       end
 
       def test_references_column_type_with_polymorphic_adds_type
         with_change_table do |t|
-          @connection.expect :add_reference, nil, [:delete_me, :taggable, polymorphic: true]
+          expect :add_reference, nil, [:delete_me, :taggable], polymorphic: true
           t.references :taggable, polymorphic: true
         end
       end
 
       def test_remove_references_column_type_with_polymorphic_removes_type
         with_change_table do |t|
-          @connection.expect :remove_reference, nil, [:delete_me, :taggable, polymorphic: true]
+          expect :remove_reference, nil, [:delete_me, :taggable], polymorphic: true
           t.remove_references :taggable, polymorphic: true
         end
       end
 
       def test_references_column_type_with_polymorphic_and_options_null_is_false_adds_table_flag
         with_change_table do |t|
-          @connection.expect :add_reference, nil, [:delete_me, :taggable, polymorphic: true, null: false]
+          expect :add_reference, nil, [:delete_me, :taggable], polymorphic: true, null: false
           t.references :taggable, polymorphic: true, null: false
         end
       end
 
       def test_remove_references_column_type_with_polymorphic_and_options_null_is_false_removes_table_flag
         with_change_table do |t|
-          @connection.expect :remove_reference, nil, [:delete_me, :taggable, polymorphic: true, null: false]
+          expect :remove_reference, nil, [:delete_me, :taggable], polymorphic: true, null: false
           t.remove_references :taggable, polymorphic: true, null: false
         end
       end
 
       def test_references_column_type_with_polymorphic_and_type
         with_change_table do |t|
-          @connection.expect :add_reference, nil, [:delete_me, :taggable, polymorphic: true, type: :string]
+          expect :add_reference, nil, [:delete_me, :taggable], polymorphic: true, type: :string
           t.references :taggable, polymorphic: true, type: :string
         end
       end
 
       def test_remove_references_column_type_with_polymorphic_and_type
         with_change_table do |t|
-          @connection.expect :remove_reference, nil, [:delete_me, :taggable, polymorphic: true, type: :string]
+          expect :remove_reference, nil, [:delete_me, :taggable], polymorphic: true, type: :string
           t.remove_references :taggable, polymorphic: true, type: :string
         end
       end
 
       def test_timestamps_creates_updated_at_and_created_at
         with_change_table do |t|
-          @connection.expect :add_timestamps, nil, [:delete_me, null: true]
+          expect :add_timestamps, nil, [:delete_me], null: true
           t.timestamps null: true
         end
       end
 
       def test_remove_timestamps_creates_updated_at_and_created_at
         with_change_table do |t|
-          @connection.expect :remove_timestamps, nil, [:delete_me, { null: true }]
+          expect :remove_timestamps, nil, [:delete_me], null: true
           t.remove_timestamps(null: true)
         end
       end
 
       def test_primary_key_creates_primary_key_column
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :id, :primary_key, primary_key: true, first: true]
+          expect :add_column, nil, [:delete_me, :id, :primary_key], primary_key: true, first: true
           t.primary_key :id, first: true
         end
       end
 
       def test_integer_creates_integer_column
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :foo, :integer]
-          @connection.expect :add_column, nil, [:delete_me, :bar, :integer]
+          expect :add_column, nil, [:delete_me, :foo, :integer]
+          expect :add_column, nil, [:delete_me, :bar, :integer]
           t.integer :foo, :bar
         end
       end
 
       def test_bigint_creates_bigint_column
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :foo, :bigint]
-          @connection.expect :add_column, nil, [:delete_me, :bar, :bigint]
+          expect :add_column, nil, [:delete_me, :foo, :bigint]
+          expect :add_column, nil, [:delete_me, :bar, :bigint]
           t.bigint :foo, :bar
         end
       end
 
       def test_string_creates_string_column
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :foo, :string]
-          @connection.expect :add_column, nil, [:delete_me, :bar, :string]
+          expect :add_column, nil, [:delete_me, :foo, :string]
+          expect :add_column, nil, [:delete_me, :bar, :string]
           t.string :foo, :bar
         end
       end
@@ -135,30 +149,30 @@ module ActiveRecord
       if current_adapter?(:PostgreSQLAdapter)
         def test_json_creates_json_column
           with_change_table do |t|
-            @connection.expect :add_column, nil, [:delete_me, :foo, :json]
-            @connection.expect :add_column, nil, [:delete_me, :bar, :json]
+            expect :add_column, nil, [:delete_me, :foo, :json]
+            expect :add_column, nil, [:delete_me, :bar, :json]
             t.json :foo, :bar
           end
         end
 
         def test_xml_creates_xml_column
           with_change_table do |t|
-            @connection.expect :add_column, nil, [:delete_me, :foo, :xml]
-            @connection.expect :add_column, nil, [:delete_me, :bar, :xml]
+            expect :add_column, nil, [:delete_me, :foo, :xml]
+            expect :add_column, nil, [:delete_me, :bar, :xml]
             t.xml :foo, :bar
           end
         end
 
         def test_exclusion_constraint_creates_exclusion_constraint
           with_change_table do |t|
-            @connection.expect :add_exclusion_constraint, nil, [:delete_me, "daterange(start_date, end_date) WITH &&", using: :gist, where: "start_date IS NOT NULL AND end_date IS NOT NULL", name: "date_overlap"]
+            expect :add_exclusion_constraint, nil, [:delete_me, "daterange(start_date, end_date) WITH &&", using: :gist, where: "start_date IS NOT NULL AND end_date IS NOT NULL", name: "date_overlap"]
             t.exclusion_constraint "daterange(start_date, end_date) WITH &&", using: :gist, where: "start_date IS NOT NULL AND end_date IS NOT NULL", name: "date_overlap"
           end
         end
 
         def test_remove_exclusion_constraint_removes_exclusion_constraint
           with_change_table do |t|
-            @connection.expect :remove_exclusion_constraint, nil, [:delete_me, name: "date_overlap"]
+            expect :remove_exclusion_constraint, nil, [:delete_me, name: "date_overlap"]
             t.remove_exclusion_constraint name: "date_overlap"
           end
         end
@@ -166,120 +180,120 @@ module ActiveRecord
 
       def test_column_creates_column
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :bar, :integer]
+          expect :add_column, nil, [:delete_me, :bar, :integer]
           t.column :bar, :integer
         end
       end
 
       def test_column_creates_column_with_options
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :bar, :integer, { null: false }]
+          expect :add_column, nil, [:delete_me, :bar, :integer], null: false
           t.column :bar, :integer, null: false
         end
       end
 
       def test_column_creates_column_with_index
         with_change_table do |t|
-          @connection.expect :add_column, nil, [:delete_me, :bar, :integer]
-          @connection.expect :add_index, nil, [:delete_me, :bar]
+          expect :add_column, nil, [:delete_me, :bar, :integer]
+          expect :add_index, nil, [:delete_me, :bar]
           t.column :bar, :integer, index: true
         end
       end
 
       def test_index_creates_index
         with_change_table do |t|
-          @connection.expect :add_index, nil, [:delete_me, :bar]
+          expect :add_index, nil, [:delete_me, :bar]
           t.index :bar
         end
       end
 
       def test_index_creates_index_with_options
         with_change_table do |t|
-          @connection.expect :add_index, nil, [:delete_me, :bar, { unique: true }]
+          expect :add_index, nil, [:delete_me, :bar], unique: true
           t.index :bar, unique: true
         end
       end
 
       def test_index_exists
         with_change_table do |t|
-          @connection.expect :index_exists?, nil, [:delete_me, :bar]
+          expect :index_exists?, nil, [:delete_me, :bar]
           t.index_exists?(:bar)
         end
       end
 
       def test_index_exists_with_options
         with_change_table do |t|
-          @connection.expect :index_exists?, nil, [:delete_me, :bar, { unique: true }]
+          expect :index_exists?, nil, [:delete_me, :bar], unique: true
           t.index_exists?(:bar, unique: true)
         end
       end
 
       def test_rename_index_renames_index
         with_change_table do |t|
-          @connection.expect :rename_index, nil, [:delete_me, :bar, :baz]
+          expect :rename_index, nil, [:delete_me, :bar, :baz]
           t.rename_index :bar, :baz
         end
       end
 
       def test_change_changes_column
         with_change_table do |t|
-          @connection.expect :change_column, nil, [:delete_me, :bar, :string]
+          expect :change_column, nil, [:delete_me, :bar, :string]
           t.change :bar, :string
         end
       end
 
       def test_change_changes_column_with_options
         with_change_table do |t|
-          @connection.expect :change_column, nil, [:delete_me, :bar, :string, { null: true }]
+          expect :change_column, nil, [:delete_me, :bar, :string], null: true
           t.change :bar, :string, null: true
         end
       end
 
       def test_change_default_changes_column
         with_change_table do |t|
-          @connection.expect :change_column_default, nil, [:delete_me, :bar, :string]
+          expect :change_column_default, nil, [:delete_me, :bar, :string]
           t.change_default :bar, :string
         end
       end
 
       def test_change_null_changes_column
         with_change_table do |t|
-          @connection.expect :change_column_null, nil, [:delete_me, :bar, true, nil]
+          expect :change_column_null, nil, [:delete_me, :bar, true, nil]
           t.change_null :bar, true
         end
       end
 
       def test_remove_drops_single_column
         with_change_table do |t|
-          @connection.expect :remove_columns, nil, [:delete_me, :bar]
+          expect :remove_columns, nil, [:delete_me, :bar]
           t.remove :bar
         end
       end
 
       def test_remove_drops_multiple_columns
         with_change_table do |t|
-          @connection.expect :remove_columns, nil, [:delete_me, :bar, :baz]
+          expect :remove_columns, nil, [:delete_me, :bar, :baz]
           t.remove :bar, :baz
         end
       end
 
       def test_remove_drops_multiple_columns_when_column_options_are_given
         with_change_table do |t|
-          @connection.expect :remove_columns, nil, [:delete_me, :bar, :baz, type: :string, null: false]
+          expect :remove_columns, nil, [:delete_me, :bar, :baz], type: :string, null: false
           t.remove :bar, :baz, type: :string, null: false
         end
       end
 
       def test_remove_index_removes_index_with_options
         with_change_table do |t|
-          @connection.expect :remove_index, nil, [:delete_me, :bar, { unique: true }]
+          expect :remove_index, nil, [:delete_me, :bar], unique: true
           t.remove_index :bar, unique: true
         end
       end
 
       def test_rename_renames_column
         with_change_table do |t|
-          @connection.expect :rename_column, nil, [:delete_me, :bar, :baz]
+          expect :rename_column, nil, [:delete_me, :bar, :baz]
           t.rename :bar, :baz
         end
       end
@@ -292,14 +306,14 @@ module ActiveRecord
 
       def test_check_constraint_creates_check_constraint
         with_change_table do |t|
-          @connection.expect :add_check_constraint, nil, [:delete_me, "price > discounted_price", name: "price_check"]
+          expect :add_check_constraint, nil, [:delete_me, "price > discounted_price"], name: "price_check"
           t.check_constraint "price > discounted_price", name: "price_check"
         end
       end
 
       def test_remove_check_constraint_removes_check_constraint
         with_change_table do |t|
-          @connection.expect :remove_check_constraint, nil, [:delete_me, name: "price_check"]
+          expect :remove_check_constraint, nil, [:delete_me], name: "price_check"
           t.remove_check_constraint name: "price_check"
         end
       end
diff --git a/activerecord/test/cases/tasks/sqlite_rake_test.rb b/activerecord/test/cases/tasks/sqlite_rake_test.rb
index 19daf8f1c8f..98257867aa7 100644
--- a/activerecord/test/cases/tasks/sqlite_rake_test.rb
+++ b/activerecord/test/cases/tasks/sqlite_rake_test.rb
@@ -221,8 +221,9 @@ if current_adapter?(:SQLite3Adapter)
         assert_called_with(
           Kernel,
           :system,
-          ["sqlite3", "--noop", "db_create.sqlite3", ".schema", out: "awesome-file.sql"],
-          returns: nil
+          ["sqlite3", "--noop", "db_create.sqlite3", ".schema"],
+          returns: nil,
+          out: "awesome-file.sql"
         ) do
           e = assert_raise(RuntimeError) do
             with_structure_dump_flags(["--noop"]) do
diff --git a/activestorage/test/models/attached/one_test.rb b/activestorage/test/models/attached/one_test.rb
index 7843ede045a..04847af56d2 100644
--- a/activestorage/test/models/attached/one_test.rb
+++ b/activestorage/test/models/attached/one_test.rb
@@ -31,8 +31,8 @@ class ActiveStorage::OneAttachedTest < ActiveSupport::TestCase
 
   test "attaching an existing blob from a signed ID passes record" do
     blob = create_blob(filename: "funky.jpg")
-    arguments = [blob.signed_id, record: @user]
-    assert_called_with(ActiveStorage::Blob, :find_signed!, arguments, returns: blob) do
+
+    assert_called_with(ActiveStorage::Blob, :find_signed!, [blob.signed_id], returns: blob, record: @user) do
       @user.avatar.attach blob.signed_id
     end
   end
@@ -45,8 +45,8 @@ class ActiveStorage::OneAttachedTest < ActiveSupport::TestCase
   test "attaching a new blob from a Hash to an existing record passes record" do
     hash = { io: StringIO.new("STUFF"), filename: "town.jpg", content_type: "image/jpeg" }
     blob = ActiveStorage::Blob.build_after_unfurling(**hash)
-    arguments = [hash.merge(record: @user, service_name: nil)]
-    assert_called_with(ActiveStorage::Blob, :build_after_unfurling, arguments, returns: blob) do
+    arguments = hash.merge(record: @user, service_name: nil)
+    assert_called_with(ActiveStorage::Blob, :build_after_unfurling, [], **arguments, returns: blob) do
       @user.avatar.attach hash
     end
   end
@@ -63,7 +63,7 @@ class ActiveStorage::OneAttachedTest < ActiveSupport::TestCase
     end
     arguments = { io: upload.open, filename: upload.original_filename, content_type: upload.content_type, record: @user, service_name: nil }
     blob = ActiveStorage::Blob.build_after_unfurling(**arguments)
-    assert_called_with(ActiveStorage::Blob, :build_after_unfurling, [arguments], returns: blob) do
+    assert_called_with(ActiveStorage::Blob, :build_after_unfurling, [], returns: blob, **arguments) do
       @user.avatar.attach upload
     end
   end
diff --git a/activestorage/test/models/blob_test.rb b/activestorage/test/models/blob_test.rb
index 6ac1bcc341a..669495a0cfa 100644
--- a/activestorage/test/models/blob_test.rb
+++ b/activestorage/test/models/blob_test.rb
@@ -210,15 +210,18 @@ class ActiveStorage::BlobTest < ActiveSupport::TestCase
     blob = create_blob(filename: "original.txt")
 
     arguments = [
-      blob.key,
+      blob.key
+    ]
+
+    kwargs = {
       expires_in: ActiveStorage.service_urls_expire_in,
       disposition: :attachment,
       content_type: blob.content_type,
       filename: blob.filename,
       thumb_size: "300x300",
       thumb_mode: "crop"
-    ]
-    assert_called_with(blob.service, :url, arguments) do
+    }
+    assert_called_with(blob.service, :url, arguments, **kwargs) do
       blob.url(thumb_size: "300x300", thumb_mode: "crop")
     end
   end
@@ -279,9 +282,7 @@ class ActiveStorage::BlobTest < ActiveSupport::TestCase
   test "updating the content_type updates service metadata" do
     blob = directly_upload_file_blob(filename: "racecar.jpg", content_type: "application/octet-stream")
 
-    expected_arguments = [blob.key, content_type: "image/jpeg", custom_metadata: {}]
-
-    assert_called_with(blob.service, :update_metadata, expected_arguments) do
+    assert_called_with(blob.service, :update_metadata, [blob.key], content_type: "image/jpeg", custom_metadata: {}) do
       blob.update!(content_type: "image/jpeg")
     end
   end
@@ -290,16 +291,17 @@ class ActiveStorage::BlobTest < ActiveSupport::TestCase
     blob = directly_upload_file_blob(filename: "racecar.jpg", content_type: "application/octet-stream")
 
     expected_arguments = [
-      blob.key,
-      {
-        content_type: "application/octet-stream",
-        disposition: :attachment,
-        filename: blob.filename,
-        custom_metadata: { "test" => true }
-      }
+      blob.key
     ]
 
-    assert_called_with(blob.service, :update_metadata, expected_arguments) do
+    expected_kwargs = {
+      content_type: "application/octet-stream",
+      disposition: :attachment,
+      filename: blob.filename,
+      custom_metadata: { "test" => true }
+    }
+
+    assert_called_with(blob.service, :update_metadata, expected_arguments, **expected_kwargs) do
       blob.update!(metadata: { custom: { "test" => true } })
     end
   end
diff --git a/activesupport/lib/active_support/testing/method_call_assertions.rb b/activesupport/lib/active_support/testing/method_call_assertions.rb
index 72451faaa8c..f146eefce03 100644
--- a/activesupport/lib/active_support/testing/method_call_assertions.rb
+++ b/activesupport/lib/active_support/testing/method_call_assertions.rb
@@ -17,9 +17,9 @@ module ActiveSupport
           assert_equal times, times_called, error
         end
 
-        def assert_called_with(object, method_name, args, returns: nil, &block)
+        def assert_called_with(object, method_name, args, returns: false, **kwargs, &block)
           mock = Minitest::Mock.new
-          mock.expect(:call, returns, args)
+          expect_called_with(mock, args, returns: returns, **kwargs)
 
           object.stub(method_name, mock, &block)
 
@@ -30,6 +30,24 @@ module ActiveSupport
           assert_called(object, method_name, message, times: 0, &block)
         end
 
+        #--
+        # This method is a temporary wrapper for mock.expect as part of
+        # the Minitest 5.16 / Ruby 3.0 kwargs transition. It can go away
+        # when we drop support for Ruby 2.7.
+        if Minitest::Mock.instance_method(:expect).parameters.map(&:first).include?(:keyrest)
+          def expect_called_with(mock, args, returns: false, **kwargs)
+            mock.expect(:call, returns, args, **kwargs)
+          end
+        else
+          def expect_called_with(mock, args, returns: false, **kwargs)
+            if !kwargs.empty?
+              mock.expect(:call, returns, [*args, kwargs])
+            else
+              mock.expect(:call, returns, args)
+            end
+          end
+        end
+
         def assert_called_on_instance_of(klass, method_name, message = nil, times: 1, returns: nil)
           times_called = 0
           klass.define_method("stubbed_#{method_name}") do |*|
diff --git a/activesupport/test/cache/stores/mem_cache_store_test.rb b/activesupport/test/cache/stores/mem_cache_store_test.rb
index 7d71f05ba97..bfcf56a29a6 100644
--- a/activesupport/test/cache/stores/mem_cache_store_test.rb
+++ b/activesupport/test/cache/stores/mem_cache_store_test.rb
@@ -175,7 +175,7 @@ class MemCacheStoreTest < ActiveSupport::TestCase
     cache = lookup_store(raw: true, namespace: nil)
 
     Time.stub(:now, Time.now) do
-      assert_called_with client(cache), :set, [ "key_with_expires_at", "bar", 30 * 60, Hash ] do
+      assert_called_with client(cache), :set, ["key_with_expires_at", "bar", 30 * 60], namespace: nil, pool: false, raw: true, compress_threshold: 1024, expires_in: 1800.0 do
         cache.write("key_with_expires_at", "bar", expires_at: 30.minutes.from_now)
       end
     end
@@ -260,7 +260,8 @@ class MemCacheStoreTest < ActiveSupport::TestCase
 
   def test_unless_exist_expires_when_configured
     cache = lookup_store(namespace: nil)
-    assert_called_with client(cache), :add, [ "foo", Object, 1, Hash ] do
+
+    assert_called_with client(cache), :add, ["foo", Object, 1], namespace: nil, pool: false, compress_threshold: 1024, expires_in: 1, unless_exist: true do
       cache.write("foo", "bar", expires_in: 1, unless_exist: true)
     end
   end
diff --git a/railties/test/application/test_runner_test.rb b/railties/test/application/test_runner_test.rb
index cfce5d3ff51..d2edfae2942 100644
--- a/railties/test/application/test_runner_test.rb
+++ b/railties/test/application/test_runner_test.rb
@@ -747,7 +747,7 @@ module ApplicationTests
 
       output = run_test_command(file)
 
-      assert_match "RuntimeError: Wrapped undumpable exception for: FailTest::BadError", output
+      assert_match(/RuntimeError: (Wrapped undumpable exception|result not reported)/, output)
       assert_match "1 runs, 0 assertions, 0 failures, 1 errors", output
     end