Update stringio tests for 3.1.9

Author: headius

test/mri/stringio/test_ractor.rb

@@ -8,6 +8,10 @@ def setup
 
   def test_ractor
     assert_in_out_err([], <<-"end;", ["true"], [])
+      class Ractor
+        alias value take unless method_defined? :value # compat with Ruby 3.4 and olders
+      end
+
       require "stringio"
       $VERBOSE = nil
       r = Ractor.new do
@@ -17,7 +21,7 @@ def test_ractor
         io.puts "def"
         "\0\0\0\0def\n" == io.string
       end
-      puts r.take
+      puts r.value
     end;
   end
 end

test/mri/stringio/test_stringio.rb

@@ -14,6 +14,24 @@ def open_file(content)
 
   include TestEOF::Seek
 
+  def test_do_not_mutate_shared_buffers
+    # Ensure we have two strings that are not embedded but have the same shared
+    # string reference.
+    #
+    # In this case, we must use eval because we need two strings literals that
+    # are long enough they cannot be embedded, but also contain the same bytes.
+
+    a = eval("+"+("x" * 1024).dump)
+    b = eval("+"+("x" * 1024).dump)
+
+    s = StringIO.new(b)
+    s.getc
+    s.ungetc '#'
+
+    # We mutated b, so a should not be mutated
+    assert_equal("x", a[0])
+  end
+
   def test_version
     assert_kind_of(String, StringIO::VERSION)
   end
@@ -46,6 +64,35 @@ def test_null
     assert_nil io.gets
     io.puts "abc"
     assert_nil io.string
+
+    # Null device StringIO just drop ungot string
+    io.ungetc '#'
+    assert_nil io.getc
+  end
+
+  def test_eof_null
+    io = StringIO.new(nil)
+    assert_predicate io, :eof?
+  end
+
+  def test_pread_null
+    io = StringIO.new(nil)
+    assert_raise(EOFError) { io.pread(1, 0) }
+  end
+
+  def test_read_null
+    io = StringIO.new(nil)
+    assert_equal "", io.read(0)
+  end
+
+  def test_seek_null
+    io = StringIO.new(nil)
+    assert_equal(0, io.seek(0, IO::SEEK_SET))
+    assert_equal(0, io.pos)
+    assert_equal(0, io.seek(0, IO::SEEK_CUR))
+    assert_equal(0, io.pos)
+    assert_equal(0, io.seek(0, IO::SEEK_END))  # This should not segfault
+    assert_equal(0, io.pos)
   end
 
   def test_truncate
@@ -465,6 +512,11 @@ def test_seek
     f.close unless f.closed?
   end
 
+  def test_seek_frozen_string
+    f = StringIO.new(-"1234")
+    assert_equal(0, f.seek(1))
+  end
+
   def test_each_byte
     f = StringIO.new("1234")
     a = []
@@ -944,7 +996,7 @@ def test_overflow
     intptr_max = RbConfig::LIMITS["INTPTR_MAX"]
     return if intptr_max > StringIO::MAX_LENGTH
     limit = intptr_max - 0x10
-    assert_separately(%w[-rstringio], "#{<<-"begin;"}\n#{<<-"end;"}")
+    assert_separately(%w[-W0 -rstringio], "#{<<-"begin;"}\n#{<<-"end;"}")
     begin;
       limit = #{limit}
       ary = []
@@ -1012,6 +1064,20 @@ def test_coderange_after_overwrite
     assert_predicate(s.string, :ascii_only?)
   end
 
+  def test_coderange_after_read_into_buffer
+    s = StringIO.new("01234567890".b)
+
+    buf = "¿Cómo estás? Ça va bien?"
+    assert_not_predicate(buf, :ascii_only?)
+
+    assert_predicate(s.string, :ascii_only?)
+
+    s.read(10, buf)
+
+    assert_predicate(buf, :ascii_only?)
+    assert_equal '0123456789', buf
+  end
+
   require "objspace"
   if ObjectSpace.respond_to?(:dump) && ObjectSpace.dump(eval(%{"test"})).include?('"chilled":true') # Ruby 3.4+ chilled strings
     def test_chilled_string
@@ -1030,6 +1096,13 @@ def test_chilled_string_string_set
       assert_equal("test", io.string)
       assert_same(chilled_string, io.string)
     end
+
+    def test_chilled_string_set_enocoding
+      chilled_string = eval(%{""})
+      io = StringIO.new(chilled_string)
+      assert_warning("") { io.set_encoding(Encoding::BINARY) }
+      assert_same(chilled_string, io.string)
+    end
   end
 
   private