Weekly Update - Aug 7th, 2015

Steven Sinatra (@diagramatics)

io.js and Node.js News — August 7th

io.js v3.0 and the new goodness, breaking changes, and our ongoing call for an LTS build V8 maintainer.

io.js v3.0 Release

This week, io.js v3.0.0 is released! Since this is a major version bump, new features have been introduced to io.js. These are:

  • V8 upgrade from v4.2 to v4.4. Rod Vagg (@rvagg) has a Gist containing the changelogs of v4.3 and v4.4.
  • Computed property names ({['foo'+'bar']:'bam'}) is now shipped without the need for any harmony- flag.
  • Unicode escape sequence (\u{xxxxx}) is also shipped. There is no need for the --harmony option anymore.
  • Previously classes are available but built-in Array subclasses are not supported or problematic. The new version of V8 has solved this problem.
  • The spread operator (...) is supported with the --es-staging flag. This allows you to use it in places where multiple arguments (for function calls) or multiple elements (for array literals) are expected.
  • The Rest parameters (function(...args) {}) are implemented behind the --es-staging flag as well.
  • REPL now gets a history file. Previously REPL needs to specify NODE_REPL_HISTORY_FILE but the current version will have the history saved by default.
  • Buffer is now a subclass of Uint8Array.
  • The smalloc module has been removed, and the freelist module has now been deprecated.

With a major version bump, there are also breaking changes. These include:

  • Changes on Buffer.concat, dgram send() error and http server timing behaviors.
  • The upgrade on V8, which gives the need for recompiling of all native add-ons and the new Maybe<> and MaybeLocal<> types for add-on authors to transition to these new APIs as soon as possible.
  • HTTP status codes. The code mappings conform to the IANA standard now and will be a backwards incompatible change to consumers that depend on the text value of a header.
  • The HTTP agent .getName(), which fixes the unnecessary extra colon at the end of the return values.

You can find out more information about this release in the complete changelog, the Breaking Changes document and the pull request for the release proposal. In addition, Yosuke Furukawa has made a repo with details about the new features.

Notable changes

  • buffer:
    • Due to changes in V8, it has been necessary to reimplement Buffer on top of V8's Uint8Array. Every effort has been made to minimize the performance impact, however Buffer instantiation is measurably slower. Access operations may be faster in some circumstances but the exact performance profile and difference over previous versions will depend on how Buffer is used within applications. (Trevor Norris) #1825.
    • Buffer can now take ArrayBuffers as a constructor argument (Trevor Norris) #2002.
    • When a single buffer is passed to Buffer.concat(), a new, copied Buffer object will be returned; previous behavior was to return the original Buffer object (Sakthipriyan Vairamani) #1937.
  • build: PPC support has been added to core to allow compiling on pLinux BE and LE (AIX support coming soon) (Michael Dawson) #2124.
  • dgram: If an error occurs within socket.send() and a callback has been provided, the error is only passed as the first argument to the callback and not emitted on the socket object; previous behavior was to do both (Matteo Collina & Chris Dickinson) #1796
  • freelist: Deprecate the undocumented freelist core module (Sakthipriyan Vairamani) #2176.
  • http:
    • Status codes now all use the official IANA names as per RFC7231, e.g. http.STATUS_CODES[414] now returns 'URI Too Long' rather than 'Request-URI Too Large' (jomo) #1470.
    • Calling .getName() on an HTTP agent no longer returns a trailing colon, HTTPS agents will no longer return an extra colon near the middle of the string (Brendan Ashworth) #1617.
  • node:
    • NODE_MODULE_VERSION has been bumped to 45 to reflect the break in ABI (Rod Vagg) #2096.
    • Introduce a new process.release object that contains a name property set to 'io.js' and sourceUrl, headersUrl and libUrl (Windows only) properties containing URLs for the relevant resources; this is intended to be used by node-gyp (Rod Vagg) #2154.
    • The version of node-gyp bundled with io.js now downloads and uses a tarball of header files from iojs.org rather than the full source for compiling native add-ons; it is hoped this is a temporary floating patch and the change will be upstreamed to node-gyp soon (Rod Vagg) #2066.
  • repl: Persistent history is now enabled by default. The history file is located at ~/.node_repl_history, which can be overridden by the new environment variable NODE_REPL_HISTORY. This deprecates the previous NODE_REPL_HISTORY_FILE variable. Additionally, the format of the file has been changed to plain text to better handle file corruption. (Jeremiah Senkpiel) #2224.
  • smalloc: The smalloc module has been removed as it is no longer possible to provide the API due to changes in V8 (Ben Noordhuis) #2022.
  • tls: Add server.getTicketKeys() and server.setTicketKeys() methods for TLS session key rotation (Fedor Indutny) #2227.
  • v8: Upgraded to
    • ES6: Enabled computed property names
    • ES6: Array can now be subclassed in strict mode
    • ES6: Implement rest parameters in staging, use the --harmony-rest-parameters command line flag
    • ES6: Implement the spread operator in staging, use the --harmony-spreadcalls command line flag
    • Removed SetIndexedPropertiesToExternalArrayData and related APIs, forcing a shift to Buffer to be reimplemented based on Uint8Array
    • Introduction of Maybe and MaybeLocal C++ API for objects which may or may not have a value.
    • Added support for PPC

See also https://github.com/nodejs/node/wiki/Breaking-Changes#300-from-2x for a summary of the breaking changes (SEMVER-MAJOR).

Known issues

See https://github.com/nodejs/node/labels/confirmed-bug for complete and current list of known issues.

  • Some problems with unreferenced timers running during beforeExit are still to be resolved. See #1264.
  • Surrogate pair in REPL can freeze terminal. #690
  • process.send() is not synchronous as the docs suggest, a regression introduced in 1.0.2, see #760.
  • Calling dns.setServers() while a DNS query is in progress can cause the process to crash on a failed assertion. #894
  • url.resolve may transfer the auth portion of the url when resolving between two full hosts, see #1435.

Community Updates

If you have spotted or written something about Node.js and io.js, do come over to our Evangelism team repo and suggest it on the Issues page, specifically the Weekly Updates issue.

Upcoming Events

  • BrazilJS Conf tickets are on sale, August 21st - 22nd at Shopping Center BarraShoppingSul
  • NodeConf EU tickets are on sale, September 6th - 9th at Waterford, Ireland
  • Node.js Italian Conference tickets are on sale, October 10th at Desenzano - Brescia, Italy
  • JSConf CO, October 16th - 17th at Ruta N, Medellin

Have an event about Node.js and io.js coming up? You can put your events here through the Evangelism team repo and announce it in the Issues page, specifically the Weekly Updates issue.