guix-play/guix/import/gem.scm
David Thompson a96524cc7d import: gem: Fix minor bug and add unit test.
* guix/import/gem.scm (make-gem-sexp): Properly handle an empty list of
  licenses.  When rendering a list of licenses, cons 'list onto the front of
  the expression.
* tests/gem.scm: New file.
* Makefile.am (SCM_TESTS): Add it.
2015-09-01 20:00:01 -04:00

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Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 David Thompson <davet@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix import gem)
#:use-module (ice-9 match)
#:use-module (ice-9 pretty-print)
#:use-module (rnrs bytevectors)
#:use-module (json)
#:use-module (web uri)
#:use-module (guix import utils)
#:use-module (guix import json)
#:use-module (guix packages)
#:use-module (guix licenses)
#:use-module (guix base32)
#:export (gem->guix-package))
(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")))
(define (ruby-package-name name)
"Given the NAME of a package on RubyGems, return a Guix-compliant name for
the package."
(if (string-prefix? "ruby-" name)
(snake-case name)
(string-append "ruby-" (snake-case name))))
(define (hex-string->bytevector str)
"Convert the hexadecimal encoded string STR to a bytevector."
(define hex-char->int
(match-lambda
(#\0 0)
(#\1 1)
(#\2 2)
(#\3 3)
(#\4 4)
(#\5 5)
(#\6 6)
(#\7 7)
(#\8 8)
(#\9 9)
(#\a 10)
(#\b 11)
(#\c 12)
(#\d 13)
(#\e 14)
(#\f 15)))
(define (read-byte i)
(let ((j (* 2 i)))
(+ (hex-char->int (string-ref str (1+ j)))
(* (hex-char->int (string-ref str j)) 16))))
(let* ((len (/ (string-length str) 2))
(bv (make-bytevector len)))
(let loop ((i 0))
(if (= i len)
bv
(begin
(bytevector-u8-set! bv i (read-byte i))
(loop (1+ i)))))))
(define (make-gem-sexp name version hash home-page description
dependencies licenses)
"Return the `package' s-expression for a Ruby package with the given NAME,
VERSION, HASH, HOME-PAGE, DESCRIPTION, DEPENDENCIES, and LICENSES."
`(package
(name ,(ruby-package-name name))
(version ,version)
(source (origin
(method url-fetch)
(uri (rubygems-uri ,name version))
(sha256
(base32
,(bytevector->nix-base32-string
(hex-string->bytevector hash))))))
(build-system ruby-build-system)
,@(if (null? dependencies)
'()
`((propagated-inputs
(,'quasiquote
,(map (lambda (name)
`(,name
(,'unquote
,(string->symbol name))))
dependencies)))))
(synopsis ,description) ; nothing better to use
(description ,description)
(home-page ,home-page)
(license ,(match licenses
(() #f)
((license) (license->symbol license))
(_ `(list ,@(map license->symbol licenses)))))))
(define* (gem->guix-package package-name #:optional version)
"Fetch the metadata for PACKAGE-NAME from rubygems.org, and return the
`package' s-expression corresponding to that package, or #f on failure."
(let ((package (rubygems-fetch package-name)))
(and package
(let ((name (assoc-ref package "name"))
(version (assoc-ref package "version"))
(hash (assoc-ref package "sha"))
(description (assoc-ref package "info"))
(home-page (assoc-ref package "homepage_uri"))
(dependencies (map (lambda (dep)
(let ((name (assoc-ref dep "name")))
(if (string=? name "bundler")
"bundler" ; special case, no prefix
(ruby-package-name name))))
(assoc-ref* package "dependencies"
"runtime")))
(licenses (map string->license
(assoc-ref package "licenses"))))
(make-gem-sexp name version hash home-page
description dependencies licenses)))))