EMCAScript Media Types Updates
draft-bfarias-javascript-mjs-00

Network Working Group                                          B. Farias
Internet-Draft
Updates: 4329 (if approved)                                    M. Miller
Intended status: Informational                                   Mozilla
Expires: February 17, 2018                               August 16, 2017

                     EMCAScript Media Types Updates
                    draft-bfarias-javascript-mjs-00

Abstract

   This document proposes updates to the ECMAScript media types,
   superseding the existing registrations for "application/javascript"
   and "text/javascript" by adding an additional extension and removing
   usage warnings.  This document updates RFC4329, "Scripting Media
   Types".

Note to Readers

   The issues list for this draft can be found at
   https://github.com/bfarias/I-D/labels/javascript-mjs.

   The most recent (often, unpublished) draft is at
   https://github.com/bfarias/I-D/tree/master/javascript-mjs.

   Recent changes are listed at https://github.com/bfarias/I-
   D/commits/master/javascript-mjs.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 17, 2018.

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Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Notational Conventions  . . . . . . . . . . . . . . . . . . .   3
   4.  Registration  . . . . . . . . . . . . . . . . . . . . . . . .   3
     4.1.  text/javascript . . . . . . . . . . . . . . . . . . . . .   3
     4.2.  application/javascript  . . . . . . . . . . . . . . . . .   4
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   This document updates the existing media types for the ECMAScript
   programming language.  It supersedes the media types registrations in
   [RFC4329] for "application/javascript" and "text/javascript".

2.  Background

   In order to formalize support for modular programs [ECMA-262] now
   defines two top-level goal symbols for the ECMAScript grammar.  This
   means that (in the absence of additional information) there are two
   possible interpretations for any given ECMAScript Source Text.  The
   TC39 standards body for ECMAScript has determined that media types
   are outside of their scope of work [TC39-MIME-ISSUE].

   It is not possible to fully determine if a Source Text of ECMAScript
   is meant to be parsed in the Module or Script grammar goals based
   upon content alone.  Therefore, scripting environments must use out
   of band information in order to determine what goal a Source Text

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   should be treated as.  To this end some scripting environments have
   chosen to adopt a new file extension of .mjs for determining the goal
   of a given Source Text.

3.  Notational Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

4.  Registration

   The ECMAScript media types are to be updated to point to a non-vendor
   specific standard undated specification of ECMAScript.  In addition,
   a new file extension of .mjs is to be added to the list of file
   extensions with the restriction that it must correspond to the Module
   grammar of [ECMA-262].  Finally, the [HTML] specification is using
   text/javascript as the default media type of ECMAScript when
   preparing script tags; therefore, text/javascript has been moved
   intended usage from OBSOLETE to COMMON.

4.1.  text/javascript

   Type name:  text

   Subtype name:  javascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

   Encoding considerations:  The same as the considerations in section
      3.1 of [RFC3023].

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

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      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  COMMON

   Restrictions on usage:  The file extension .mjs must be parsed using
      the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>

4.2.  application/javascript

   Type name:  application

   Subtype name:  javascript

   Required parameters:  none

   Optional parameters:  charset, see section 4.1 of [RFC4329].

   Encoding considerations:  The same as the considerations in section
      3.2 of [RFC3023].

   Security considerations:  See section 5 of [RFC4329].

   Interoperability considerations:  See notes in various sections of
      [RFC4329].  This media type does not specify the grammar of
      [ECMA-262] used.

   Published specification:  [[RFCXXXX]]

   Applications which use this media type:  Script interpreters as
      discussed in [RFC4329].

   Additional information:

      Magic number(s):  n/a

      File extension(s):  .js, .mjs

      Macintosh File Type Code(s):  TEXT

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   Person & email address to contact for further information:  See
      Author's Address section.

   Intended usage:  COMMON

   Restrictions on usage:  The file extension .mjs must be parsed using
      the Module grammar of [ECMA-262]

   Author:  See Author's Address section.

   Change controller:  IESG <iesg@ietf.org>.

5.  References

5.1.  Normative References

   [ECMA-262]
              Ecma International, "Standard ECMA-262: ECMAScript
              Language Specification", August 2017, <http://www.ecma-
              international.org/publications/standards/Ecma-262.htm>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC3023]  Murata, M., St. Laurent, S., and D. Kohn, "XML Media
              Types", RFC 3023, DOI 10.17487/RFC3023, January 2001,
              <http://www.rfc-editor.org/info/rfc3023>.

   [RFC4329]  Hoehrmann, B., "Scripting Media Types", RFC 4329,
              DOI 10.17487/RFC4329, April 2006,
              <http://www.rfc-editor.org/info/rfc4329>.

5.2.  Informative References

   [HTML]     WHATWG, "HTML Living Standard", August 2017,
              <https://html.spec.whatwg.org/multipage/
              scripting.html#prepare-a-script>.

   [TC39-MIME-ISSUE]
              TC39, "Add `application/javascript+module` mime to remove
              ambiguity5", August 2017, <https://web.archive.org/web/201
              70814193912/https://github.com/tc39/ecma262/issues/322>.

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Appendix A.  Acknowledgements

   Thanks to Suresh Krishnan, Alexey Melnikov, Mark Nottingham, James
   Snell, Matthew A.  Miller, Adam Roach, and Allen Wirfs-Brock for
   guiding me through this process.

Authors' Addresses

   Bradley Farias

   Email: bradley.meck@gmail.com

   Matthew A. Miller
   Mozilla

   Email: linuxwolf+ietf@outer-planes.net

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