Ruby 2.3 specs

[eregon]

We should aim to write specs for all new features, as usually the coverage is rather limited and it would greatly help other implementations to get the behavior right and faster.

From https://github.com/ruby/ruby/blob/v2_3_0/NEWS:
Only relevant items are kept for brevity.

Changes since the 2.2.0 release

Language changes

• frozen-string-literal pragma:
  • 8a76900 new pragma, frozen-string-literal has been experimentally introduced.
    Feature #8976
  • b9c349e besides, --enable/--disable=frozen-string-literal options also have
    been introduced. Feature #8976
  • a0e55db command line options --debug or --debug=frozen-string-literal enable
    additional debugging mode which shows created location with at frozen
    object error (RuntimeError).
    Feature #11725
• safe navigation operator:
  • Add specs for a safe navigator. #274 new method call syntax, object&.foo, method #foo is called on
    object if it is not nil.
    this is similar to try! in Active Support, except:
    • method name is syntactically required
      obj.try! {} # valid
      obj&. {} # syntax error
    • arguments are evaluated only if a call is made:
      obj.try!(:foo, bar()) # bar() is always evaluated
obj&.foo(bar()) # bar() is conditionally evaluated
    • attribute assignment is valid
      obj&.attr += 1
      Feature #11537
• the did_you_mean gem:
  • DidYouMean specs for ruby 2.3 #351 When a NameError or NoMethodError occurs because of a typo in the name,
    the did_you_mean gem automatically suggests other names similar to the
    method name.

    "Yuki".starts_with?("Y")
    # => NoMethodError: undefined method `starts_with?' for "Yuki":String
    #    Did you mean?  start_with?

• indented here document:
  • 57c69fc More specs for "squiggly" heredoc. #340 new string literal, here document starts with <<~.
    refer doc/syntax/literals.rdoc for more details.
    Feature #9098

Core classes updates (outstanding ones only)

• ARGF
  • 0938149 ARGF.read_nonblock supports exception: false like IO#read_nonblock.
    Feature #11358
• Array
  • 0cf2e94 Array#bsearch_index Feature #10730
  • Ruby 2.3's #dig #161 bugs.ruby-lang.org/issues/11762: Add spec for Array#dig with non-numeric index #169 do not mind excepction class #170 dig method update #171 separate TypeError cases on dig #172 Array#dig Feature #11643
• Comparable
  • f59a862 Comparable#== no longer rescues exceptions Feature #7688
• Enumerable
  • 3543656 Enumerable#grep_v is added as inverse version of Enumerable#grep.
    Feature #11049
  • [ruby-2.3 core/enumerable] - Add specs for Enumerable#chunk_while #168 Enumerable#chunk_while Feature #10769
• Enumerator::Lazy
  • 59b2043 Enumerator::Lazy#grep_v Feature #11773
• File
  • 48060b6 File.mkfifo Feature #11536
  • Add spec for File::TMPFILE #356 Add File::TMPFILE corresponding to O_TMPFILE
• Hash
  • 66e5c08 Hash#fetch_values Feature #10017
  • Ruby 2.3's #dig #161 Hash#dig Feature #11643
  • [Core/hash] Add specs for Hash #<=, #>=, #<, #> for Ruby 2.3 #160 Hash#<=, Hash#<, Hash#>=, Hash#> Feature #10984
  • Write Hash#to_proc specs #159 Hash#to_proc Feature #11653
• IO
  • Add spec for File::SHARE_DELETE #357 new mode flag File::SHARE_DELETE is available.
    this flag means to permit deleting opened file on Windows, but currently
    this affect only files opened as binary. Feature #11218
  • 4cb0765 new option parameter flags is added.
    this parameter is bitwise-ORed to oflags generated by normal mode argument.
    Feature #11253
• Kernel
  • ba17b3d Kernel#loop, when stopped by a StopIteration exception, returns
    what the enumerator has returned instead of nil. Feature #11498
• Module
  • 3e9505b Module#deprecate_constant Feature #11398
• NameError
  • Add spec for NameError#name #177 Add spec for NameError#receiver #178 NameError#receiver is added to take the receiver object. Feature #10881
• Numeric
  • 6e164b0 45c334e Numeric#positive? and Numeric#negative? are added, which return
    true when the receiver is positive and negative respectively.
    Feature #11151
• Queue (Thread::Queue)
  • 5885e2b Queue#close is added to notice a termination. Feature #10600
• String
  • 9d7f072 0391aea String#+@ and String#-@ are added to get mutable/frozen strings.
    Feature #11782
  • 214cf9e String.new now accepts new option parameter encoding.
    Feature #11785
• Struct
  • 065e422 Struct#dig Feature #11688
• Thread
  • [ruby-2.3 core/thread] - Add specs for Thread#name and Thread#name= #165 Thread#name, Thread#name= are added to handle thread names Feature #11251

Core classes compatibility issues (excluding feature bug fixes)

• Array
  • Add specs for Array#reject!, delete_if 2.3 change #273 Array#select!, Array#keep_if, Array#reject!, and Array#delete_if
    no longer changes the receiver array instantly every time the
    block is called. Feature #10714
  • spec for "no longer try to call #to_ary method on elements beyond the given level." #307 Array#flatten and Array#flatten! no longer try to call #to_ary
    method on elements beyond the given level. Bug #10748
  • spec for "no longer try to call #to_ary method on elements beyond the given level." #307 Array#inspect doesn't raise error even if its content returns
    a string which is not compatible with Encoding.default_external
    as inspected result. Feature #11801
• Enumerable
  • 376c9ea 8b118fd Enumerable#chunk and Enumerable#slice_before no longer takes the
    initial_state argument. Feature #10958
    Use a local variable instead to maintain a state.
• File::Stat
  • 67f285b On Windows File::Stat#ino always returned 0, but now returns
    BY_HANDLE_FILE_INFORMATION.nFileIndexHigh/Low. Feature #11216
• Hash
  • spec for "no longer try to call #to_ary method on elements beyond the given level." #307 Hash#inspect doesn't raise error even if its content returns
    a string which is not compatible with Encoding.default_external
    as inspected result. Feature #11801
• IO
  • adfd6bd IO#close doesn't raise when the IO object is closed. Feature #10718
  • 292f31f IO#each_codepoint raises an exception at incomplete character
    before EOF when conversion takes place. Bug #11444
• Module
  • e1ea963 Module#define_method and Object.define_singleton_method now
    require method body, Proc, Method, or a block, and raise
    ArgumentError if no block is given directly. Bug #11283
• pack/unpack (Array/String)
  • Add specs for unpack options J and j #331 j and J directives for pointer width integer type. Feature #11215

Stdlib updates (not pure-Ruby changes as these just depend on existing features)

• OpenSSL
  • (no specs) OpenSSL::SSL::SSLSocket#accept_nonblock and
    OpenSSL::SSL::SSLSocket#connect_nonblock supports exception: false.
• Socket
  • 600d305 Socket#connect_nonblock, Socket#accept_nonblock,
    TCPServer#accept_nonblock, UNIXServer#accept_nonblock,
    BasicSocket#recv_nonblock, BasicSocket#recvmsg_nonblock,
    BasicSocket#sendmsg_nonblock all support exception: false to return
    :wait_readable or :wait_writable symbols instead of raising
    IO::WaitReadable or IO::WaitWritable exceptions
    [Feature #10532] Feature #11229
  • e000de6 BasicSocket#recv and BasicSocket#recv_nonblock allow an output
    String buffer argument like IO#read and IO#read_nonblock to reduce
    GC overhead Feature #11242
• StringIO
  • 2a0bcb8 In read-only mode, StringIO#set_encoding no longer sets the encoding
    of its buffer string. Setting the encoding of the string directly
    without StringIO#set_encoding may cause unpredictable behavior now.
    Bug #11827

Stdlib compatibility issues (not pure-Ruby changes as these just depend on existing features)

• lib/base64.rb
  • Tests Base64#urlsafe_encode64 and Base64#urlsafe_decode64 #315 Base64.urlsafe_encode64: added a "padding" option to suppress
    the padding character ("="). Feature #10740
  • Tests Base64#urlsafe_encode64 and Base64#urlsafe_decode64 #315 Base64.urlsafe_decode64: now it accepts not only correctly-padded
    input but also unpadded input. Feature #10740
• ext/coverage/coverage.c
  • Started adding spec for coverage #217 Coverage.peek_result: new method to allow coverage to be captured without
    stopping the coverage tool. Feature #10816
• Net::FTP
  • 8126e53 Set Net::FTP.default_passive to false. #158 Connections are in passive mode per default now. The default mode can
    be changed by Net::FTP.default_passive=. Feature #11612

C API updates

• 1b4d6a2 rb_define_class_id_under() now raises a TypeError exception when the
  class is already defined but its superclass does not match the given
  superclass, as well as definitions in ruby level.
• ed92645 rb_timespec_now() is added to fetch current datetime as struct timespec.
  Feature #11558
• e976989 rb_time_timespec_new() is added to create a time object with epoch,
  nanosecond, and UTC/localtime/time offset arguments. Feature #11558