1 files changed, 49 insertions, 0 deletions
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index 7b3d63dd1b..8658097ae4 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -3630,6 +3630,55 @@ CODE
     assert_bytesplice_raise(ArgumentError, S("hello"), 0..-1, "bye", 0, 3)
   end
 
+  def test_append_bytes_into_binary
+    buf = S("".b)
+    assert_equal Encoding::BINARY, buf.encoding
+
+    buf.append_as_bytes(S("hello"))
+    assert_equal "hello".b, buf
+    assert_equal Encoding::BINARY, buf.encoding
+
+    buf.append_as_bytes(S("こんにちは"))
+    assert_equal S("helloこんにちは".b), buf
+    assert_equal Encoding::BINARY, buf.encoding
+  end
+
+  def test_append_bytes_into_utf8
+    buf = S("")
+    assert_equal Encoding::UTF_8, buf.encoding
+
+    buf.append_as_bytes(S("hello"))
+    assert_equal S("hello"), buf
+    assert_equal Encoding::UTF_8, buf.encoding
+    assert_predicate buf, :ascii_only?
+    assert_predicate buf, :valid_encoding?
+
+    buf.append_as_bytes(S("こんにちは"))
+    assert_equal S("helloこんにちは"), buf
+    assert_equal Encoding::UTF_8, buf.encoding
+    refute_predicate buf, :ascii_only?
+    assert_predicate buf, :valid_encoding?
+
+    buf.append_as_bytes(S("\xE2\x82".b))
+    assert_equal S("helloこんにちは\xE2\x82"), buf
+    assert_equal Encoding::UTF_8, buf.encoding
+    refute_predicate buf, :valid_encoding?
+
+    buf.append_as_bytes(S("\xAC".b))
+    assert_equal S("helloこんにちは€"), buf
+    assert_equal Encoding::UTF_8, buf.encoding
+    assert_predicate buf, :valid_encoding?
+  end
+
+  def test_append_bytes_into_utf32
+    buf = S("abc".encode(Encoding::UTF_32LE))
+    assert_equal Encoding::UTF_32LE, buf.encoding
+
+    buf.append_as_bytes("def")
+    assert_equal Encoding::UTF_32LE, buf.encoding
+    refute_predicate buf, :valid_encoding?
+  end
+
   def test_chilled_string
     chilled_string = eval('"chilled"')