diff --git a/docs/created.rid b/docs/created.rid
index f48ed23..96ed13c 100644
--- a/docs/created.rid
+++ b/docs/created.rid
@@ -1,4 +1,4 @@
-Mon, 04 Jul 2022 12:58:32 +0300
+Wed, 06 Jul 2022 19:57:30 +0300
 lib/zstds.rb	Wed, 06 Nov 2019 13:34:29 +0300
 lib/zstds/dictionary.rb	Mon, 04 Jul 2022 11:54:49 +0300
 lib/zstds/error.rb	Fri, 01 Jul 2022 17:12:27 +0300
diff --git a/docs/js/search_index.js.gz b/docs/js/search_index.js.gz
index 1a90737..171df6f 100644
Binary files a/docs/js/search_index.js.gz and b/docs/js/search_index.js.gz differ
diff --git a/test/stream/abstract.rb b/test/stream/abstract.rb
deleted file mode 100644
index ea79329..0000000
--- a/test/stream/abstract.rb
+++ /dev/null
@@ -1,125 +0,0 @@
-# Ruby bindings for zstd library.
-# Copyright (c) 2019 AUTHORS, MIT License.
-
-require "fcntl"
-require "stringio"
-
-require_relative "../common"
-require_relative "../minitest"
-require_relative "../validation"
-
-module ZSTDS
-  module Test
-    module Stream
-      class Abstract < Minitest::Test
-        SOURCE_PATH = Common::SOURCE_PATH
-
-        def test_invalid_initialize
-          (Validation::INVALID_STRINGS - [nil] + Validation::INVALID_ENCODINGS).each do |invalid_encoding|
-            assert_raises ValidateError do
-              target.new ::StringIO.new, {}, :external_encoding => invalid_encoding
-            end
-
-            assert_raises ValidateError do
-              target.new ::StringIO.new, {}, :internal_encoding => invalid_encoding
-            end
-          end
-
-          (Validation::INVALID_HASHES - [nil]).each do |invalid_hash|
-            assert_raises ValidateError do
-              target.new ::StringIO.new, {}, :transcode_options => invalid_hash
-            end
-          end
-        end
-
-        def test_invalid_set_encoding
-          instance = target.new ::StringIO.new
-
-          (Validation::INVALID_STRINGS - [nil] + Validation::INVALID_ENCODINGS).each do |invalid_encoding|
-            assert_raises ValidateError do
-              instance.set_encoding invalid_encoding
-            end
-
-            assert_raises ValidateError do
-              instance.set_encoding ::Encoding::BINARY, invalid_encoding
-            end
-          end
-
-          Validation::INVALID_ENCODINGS.each do |invalid_encoding|
-            assert_raises ValidateError do
-              instance.set_encoding "#{::Encoding::BINARY}:#{invalid_encoding}"
-            end
-
-            assert_raises ValidateError do
-              instance.set_encoding "#{invalid_encoding}:#{::Encoding::BINARY}"
-            end
-          end
-
-          (Validation::INVALID_HASHES - [nil]).each do |invalid_hash|
-            assert_raises ValidateError do
-              instance.set_encoding ::Encoding::BINARY, ::Encoding::BINARY, invalid_hash
-            end
-
-            assert_raises ValidateError do
-              instance.set_encoding "#{::Encoding::BINARY}:#{::Encoding::BINARY}", invalid_hash
-            end
-          end
-        end
-
-        def test_to_io
-          instance = target.new ::StringIO.new
-          assert_equal instance, instance.to_io
-        end
-
-        def test_io_delegates
-          ::File.open SOURCE_PATH, "wb+" do |file|
-            instance = target.new file
-
-            instance.autoclose = true
-            assert_predicate instance, :autoclose?
-
-            instance.binmode
-            assert_predicate instance, :binmode
-
-            instance.close_on_exec = true
-            assert_predicate instance, :close_on_exec?
-
-            # Fcntl may not be available.
-            if Fcntl.const_defined? :F_GETFL
-              stats = instance.fcntl Fcntl::F_GETFL, 0
-              refute_nil stats
-            end
-
-            instance.fdatasync
-
-            fd = instance.fileno
-            refute_nil fd
-
-            refute_predicate instance, :isatty
-            assert_nil instance.pid
-
-            instance.sync = true
-            assert_predicate instance, :sync
-
-            refute_nil instance.to_i
-            refute_predicate instance, :tty?
-          end
-        end
-
-        def test_stat
-          instance = target.new $stdout
-
-          refute_predicate instance.stat, :file?
-          refute_predicate instance.stat, :pipe?
-          refute_predicate instance.stat, :socket?
-        end
-
-        # -----
-
-        protected def target
-          self.class::Target
-        end
-      end
-    end
-  end
-end
diff --git a/test/stream/reader.test.rb b/test/stream/reader.test.rb
index 8112727..46421f5 100644
--- a/test/stream/reader.test.rb
+++ b/test/stream/reader.test.rb
@@ -1,13 +1,13 @@
 # Ruby bindings for zstd library.
 # Copyright (c) 2019 AUTHORS, MIT License.
 
+require "adsp/test/stream/abstract"
 require "set"
 require "socket"
 require "zstds/stream/reader"
 require "zstds/string"
 require "stringio"
 
-require_relative "abstract"
 require_relative "../common"
 require_relative "../minitest"
 require_relative "../option"
@@ -16,7 +16,7 @@
 module ZSTDS
   module Test
     module Stream
-      class Reader < Abstract
+      class Reader < ADSP::Test::Stream::Abstract
         Target = ZSTDS::Stream::Reader
         String = ZSTDS::String
 
diff --git a/test/stream/writer.test.rb b/test/stream/writer.test.rb
index f680f04..ce42997 100644
--- a/test/stream/writer.test.rb
+++ b/test/stream/writer.test.rb
@@ -1,13 +1,13 @@
 # Ruby bindings for zstd library.
 # Copyright (c) 2019 AUTHORS, MIT License.
 
+require "adsp/test/stream/abstract"
 require "set"
 require "socket"
 require "stringio"
 require "zstds/stream/writer"
 require "zstds/string"
 
-require_relative "abstract"
 require_relative "../common"
 require_relative "../minitest"
 require_relative "../option"
@@ -15,7 +15,7 @@
 module ZSTDS
   module Test
     module Stream
-      class Writer < Abstract
+      class Writer < ADSP::Test::Stream::Abstract
         Target = ZSTDS::Stream::Writer
         String = ZSTDS::String