bug#22752: 01/01: import: gem: Add updater.

[Leo Famulari]

On Sat, Feb 20, 2016 at 10:53:05AM +0000, Ben Woodcroft wrote:
> benwoodcroft pushed a commit to branch master
> in repository guix.
> 
> commit fbc5b815cce85a6af75226ab16acf243fd7d22ce
> Author: Ben Woodcroft <address@hidden>
> Date:   Fri Jan 1 16:56:07 2016 +1000
> 
>     import: gem: Add updater.

Since this commit, I can no longer use guix refresh.

For example:

$ ./pre-inst-env guix refresh --help
guix: refresh: command not found
Try `guix --help' for more information.
$ file guix/scripts/refresh.go 
guix/scripts/refresh.go: Guile Object, little endian, 64bit, bytecode v2.0

>     
>     * guix/import/gem.scm (guix-package->gem-name,
>       gem-package?, latest-release): New procedures.
>       (%gem-updater): New variable.
>       (rubygems-fetch): Wrap body in
>       'call-with-output-file' and 'with-error-to-port'.
>     * guix/scripts/refresh.scm (%updaters): Add %GEM-UPDATER.
>     * doc/guix.texi (Invoking guix refresh): Mention RubyGems.
> ---
>  doc/guix.texi            |    2 +
>  guix/import/gem.scm      |   63 +++++++++++++++++++++++++++++++++++++++++++--
>  guix/scripts/refresh.scm |    5 +++-
>  3 files changed, 66 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/guix.texi b/doc/guix.texi
> index c5a7de7..b991cc1 100644
> --- a/doc/guix.texi
> +++ b/doc/guix.texi
> @@ -4571,6 +4571,8 @@ the updater for @uref{http://cran.r-project.org/, CRAN} 
> packages;
>  the updater for @uref{http://www.bioconductor.org/, Bioconductor} R packages;
>  @item pypi
>  the updater for @uref{https://pypi.python.org, PyPI} packages.
> address@hidden gem
> +the updater for @uref{https://rubygems.org, RubyGems} packages.
>  @end table
>  
>  For instance, the following command only checks for updates of Emacs
> diff --git a/guix/import/gem.scm b/guix/import/gem.scm
> index 4b2a253..b46622f 100644
> --- a/guix/import/gem.scm
> +++ b/guix/import/gem.scm
> @@ -1,5 +1,6 @@
>  ;;; GNU Guix --- Functional package management for GNU
>  ;;; Copyright © 2015 David Thompson <address@hidden>
> +;;; Copryight © 2016 Ben Woodcroft <address@hidden>
>  ;;;
>  ;;; This file is part of GNU Guix.
>  ;;;
> @@ -19,21 +20,33 @@
>  (define-module (guix import gem)
>    #:use-module (ice-9 match)
>    #:use-module (ice-9 pretty-print)
> +  #:use-module (srfi srfi-1)
>    #:use-module (rnrs bytevectors)
>    #:use-module (json)
>    #:use-module (web uri)
> +  #:use-module ((guix download) #:prefix download:)
>    #:use-module (guix import utils)
>    #:use-module (guix import json)
>    #:use-module (guix packages)
> +  #:use-module (guix upstream)
>    #:use-module (guix licenses)
>    #:use-module (guix base32)
> -  #:export (gem->guix-package))
> +  #:use-module (guix build-system ruby)
> +  #:use-module (gnu packages)
> +  #:export (gem->guix-package
> +            %gem-updater))
>  
>  (define (rubygems-fetch name)
>    "Return an alist representation of the RubyGems metadata for the package 
> NAME,
>  or #f on failure."
> -  (json-fetch
> -   (string-append "https://rubygems.org/api/v1/gems/"; name ".json")))
> +  ;; XXX: We want to silence the download progress report, which is 
> especially
> +  ;; annoying for 'guix refresh', but we have to use a file port.
> +  (call-with-output-file "/dev/null"
> +    (lambda (null)
> +      (with-error-to-port null
> +        (lambda ()
> +          (json-fetch
> +           (string-append "https://rubygems.org/api/v1/gems/"; name 
> ".json")))))))
>  
>  (define (ruby-package-name name)
>    "Given the NAME of a package on RubyGems, return a Guix-compliant name for
> @@ -132,3 +145,47 @@ VERSION, HASH, HOME-PAGE, DESCRIPTION, DEPENDENCIES, and 
> LICENSES."
>                                    (assoc-ref package "licenses"))))
>             (make-gem-sexp name version hash home-page synopsis
>                            description dependencies licenses)))))
> +
> +(define (guix-package->gem-name package)
> +  "Given a PACKAGE built from rubygems.org, return the name of the
> +package on RubyGems."
> +  (let ((source-url (and=> (package-source package) origin-uri)))
> +    ;; The URL has the form:
> +    ;; 'https://rubygems.org/downloads/' +
> +    ;; package name + '-' + version + '.gem'
> +    ;; e.g. "https://rubygems.org/downloads/hashery-2.1.1.gem";
> +    (substring source-url 31 (string-rindex source-url #\-))))
> +
> +(define (gem-package? package)
> +  "Return true if PACKAGE is a gem package from RubyGems."
> +
> +  (define (rubygems-url? url)
> +    (string-prefix? "https://rubygems.org/downloads/"; url))
> +
> +  (let ((source-url (and=> (package-source package) origin-uri))
> +        (fetch-method (and=> (package-source package) origin-method)))
> +    (and (eq? fetch-method download:url-fetch)
> +         (match source-url
> +           ((? string?)
> +            (rubygems-url? source-url))
> +           ((source-url ...)
> +            (any rubygems-url? source-url))))))
> +
> +(define (latest-release guix-package)
> +  "Return an <upstream-source> for the latest release of GUIX-PACKAGE."
> +  (let* ((gem-name (guix-package->gem-name
> +                    (specification->package guix-package)))
> +         (metadata (rubygems-fetch gem-name))
> +         (version (assoc-ref metadata "version"))
> +         (url (rubygems-uri gem-name version)))
> +    (upstream-source
> +     (package guix-package)
> +     (version version)
> +     (urls (list url)))))
> +
> +(define %gem-updater
> +  (upstream-updater
> +   (name 'gem)
> +   (description "Updater for RubyGem packages")
> +   (pred gem-package?)
> +   (latest latest-release)))
> diff --git a/guix/scripts/refresh.scm b/guix/scripts/refresh.scm
> index f9e3f31..bb38f09 100644
> --- a/guix/scripts/refresh.scm
> +++ b/guix/scripts/refresh.scm
> @@ -3,6 +3,7 @@
>  ;;; Copyright © 2013 Nikita Karetnikov <address@hidden>
>  ;;; Copyright © 2014 Eric Bavier <address@hidden>
>  ;;; Copyright © 2015 Alex Kost <address@hidden>
> +;;; Copyright © 2016 Ben Woodcroft <address@hidden>
>  ;;;
>  ;;; This file is part of GNU Guix.
>  ;;;
> @@ -34,6 +35,7 @@
>                  #:select (%gnu-updater %gnome-updater))
>    #:use-module (guix import elpa)
>    #:use-module (guix import cran)
> +  #:use-module (guix import gem)
>    #:use-module (guix gnupg)
>    #:use-module (gnu packages)
>    #:use-module ((gnu packages commencement) #:select (%final-inputs))
> @@ -196,7 +198,8 @@ unavailable optional dependencies such as Guile-JSON."
>                   %elpa-updater
>                   %cran-updater
>                   %bioconductor-updater
> -                 ((guix import pypi) => %pypi-updater)))
> +                 ((guix import pypi) => %pypi-updater)
> +                 ((guix import gem) => %gem-updater)))
>  
>  (define (lookup-updater name)
>    "Return the updater called NAME."
>