import: gem: Add recursive import.

* doc/guix.texi (Invoking guix import): Document gem recursive import.
* guix/import/gem.scm (gem->guix-package): Return package and dependencies
values.
(gem-recursive-import): New procedure.
* guix/scripts/import/gem.scm (show-help, %options): Add recursive option.
(guix-import-gem): Use 'gem-recursive-import'.
* tests/gem.scm (test-json): Rename to 'test-foo-json'.
("gem->guix-package"): Use 'test-foo-json'.
(test-bar-json, test-bundler-json): New variables.
("gem-recursive-import"): New test.

4 files changed, 163 insertions, 28 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index a8e53a5308..8026bea356 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -6380,6 +6380,14 @@ The command below imports metadata for the @code{rails} Ruby package:
 guix import gem rails
 @end example
 
+@table @code
+@item --recursive
+@itemx -r
+Traverse the dependency graph of the given upstream package recursively
+and generate package expressions for all those packages that are not yet
+in Guix.
+@end table
+
 @item cpan
 @cindex CPAN
 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
diff --git a/guix/import/gem.scm b/guix/import/gem.scm
index 646163fb7b..ea576b5e4a 100644
--- a/guix/import/gem.scm
+++ b/guix/import/gem.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 David Thompson <davet@gnu.org>
 ;;; Copyright © 2016 Ben Woodcroft <donttrustben@gmail.com>
+;;; Copyright © 2018 Oleg Pykhalov <go.wigust@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -33,7 +34,8 @@
   #:use-module (guix base32)
   #:use-module (guix build-system ruby)
   #:export (gem->guix-package
-            %gem-updater))
+            %gem-updater
+            gem-recursive-import))
 
 (define (rubygems-fetch name)
   "Return an alist representation of the RubyGems metadata for the package NAME,
@@ -115,29 +117,30 @@ VERSION, HASH, HOME-PAGE, DESCRIPTION, DEPENDENCIES, and LICENSES."
                  ((license) (license->symbol license))
                  (_ `(list ,@(map license->symbol licenses)))))))
 
-(define* (gem->guix-package package-name #:optional version)
+(define* (gem->guix-package package-name #:optional (repo 'rubygems) 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"))
-               (synopsis     (assoc-ref package "info")) ; nothing better to use
-               (description  (beautify-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 synopsis
-                          description dependencies licenses)))))
+         (let* ((name         (assoc-ref package "name"))
+                (version      (assoc-ref package "version"))
+                (hash         (assoc-ref package "sha"))
+                (synopsis     (assoc-ref package "info")) ; nothing better to use
+                (description  (beautify-description
+                               (assoc-ref package "info")))
+                (home-page    (assoc-ref package "homepage_uri"))
+                (dependencies-names (map (lambda (dep) (assoc-ref dep "name"))
+                                         (assoc-ref* package "dependencies" "runtime")))
+                (dependencies (map (lambda (dep)
+                                     (if (string=? dep "bundler")
+                                         "bundler" ; special case, no prefix
+                                         (ruby-package-name dep)))
+                                   dependencies-names))
+                (licenses     (map string->license
+                                   (assoc-ref package "licenses"))))
+           (values (make-gem-sexp name version hash home-page synopsis
+                                  description dependencies licenses)
+                   dependencies-names)))))
 
 (define (guix-package->gem-name package)
   "Given a PACKAGE built from rubygems.org, return the name of the
@@ -192,3 +195,8 @@ package on RubyGems."
    (description "Updater for RubyGem packages")
    (pred gem-package?)
    (latest latest-release)))
+
+(define* (gem-recursive-import package-name #:optional version)
+  (recursive-import package-name '()
+                    #:repo->guix-package gem->guix-package
+                    #:guix-name ruby-package-name))
diff --git a/guix/scripts/import/gem.scm b/guix/scripts/import/gem.scm
index 349a0a072a..b6d9ccaae4 100644
--- a/guix/scripts/import/gem.scm
+++ b/guix/scripts/import/gem.scm
@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 David Thompson <davet@gnu.org>
+;;; Copyright © 2018 Oleg Pykhalov <go.wigust@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -25,6 +26,7 @@
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-37)
+  #:use-module (srfi srfi-41)
   #:use-module (ice-9 match)
   #:use-module (ice-9 format)
   #:export (guix-import-gem))
@@ -44,6 +46,9 @@ Import and convert the RubyGems package for PACKAGE-NAME.\n"))
   -h, --help             display this help and exit"))
   (display (G_ "
   -V, --version          display version information and exit"))
+  (display (G_ "
+  -r, --recursive        generate package expressions for all Gem packages\
+ that are not yet in Guix"))
   (newline)
   (show-bug-report-information))
 
@@ -56,6 +61,9 @@ Import and convert the RubyGems package for PACKAGE-NAME.\n"))
          (option '(#\V "version") #f #f
                  (lambda args
                    (show-version-and-exit "guix import pypi")))
+         (option '(#\r "recursive") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'recursive #t result)))
          %standard-import-options))
 
 
@@ -81,11 +89,20 @@ Import and convert the RubyGems package for PACKAGE-NAME.\n"))
                            (reverse opts))))
     (match args
       ((package-name)
-       (let ((sexp (gem->guix-package package-name)))
-         (unless sexp
-           (leave (G_ "failed to download meta-data for package '~a'~%")
-                  package-name))
-         sexp))
+       (if (assoc-ref opts 'recursive)
+           (map (match-lambda
+                  ((and ('package ('name name) . rest) pkg)
+                   `(define-public ,(string->symbol name)
+                      ,pkg))
+                  (_ #f))
+                (reverse
+                 (stream->list
+                  (gem-recursive-import package-name 'rubygems))))
+           (let ((sexp (gem->guix-package package-name)))
+             (unless sexp
+               (leave (G_ "failed to download meta-data for package '~a'~%")
+                      package-name))
+             sexp)))
       (()
        (leave (G_ "too few arguments~%")))
       ((many ...)
diff --git a/tests/gem.scm b/tests/gem.scm
index a39e8ba514..4220170ff0 100644
--- a/tests/gem.scm
+++ b/tests/gem.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 David Thompson <davet@gnu.org>
 ;;; Copyright © 2016 Ricardo Wurmus <rekado@elephly.net>
+;;; Copyright © 2018 Oleg Pykhalov <go.wigust@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -23,10 +24,11 @@
   #:use-module (guix hash)
   #:use-module (guix tests)
   #:use-module ((guix build utils) #:select (delete-file-recursively))
+  #:use-module (srfi srfi-41)
   #:use-module (srfi srfi-64)
   #:use-module (ice-9 match))
 
-(define test-json
+(define test-foo-json
   "{
   \"name\": \"foo\",
   \"version\": \"1.0.0\",
@@ -42,6 +44,34 @@
   \"licenses\": [\"MIT\", \"Apache 2.0\"]
 }")
 
+(define test-bar-json
+  "{
+  \"name\": \"bar\",
+  \"version\": \"1.0.0\",
+  \"sha\": \"f3676eafca9987cb5fe263df1edf2538bf6dafc712b30e17be3543a9680547a8\",
+  \"info\": \"Another cool gem\",
+  \"homepage_uri\": \"https://example.com\",
+  \"dependencies\": {
+    \"runtime\": [
+      { \"name\": \"bundler\" },
+    ]
+  },
+  \"licenses\": [\"MIT\", \"Apache 2.0\"]
+}")
+
+(define test-bundler-json
+  "{
+  \"name\": \"bundler\",
+  \"version\": \"1.14.2\",
+  \"sha\": \"3bb53e03db0a8008161eb4c816ccd317120d3c415ba6fee6f90bbc7f7eec8690\",
+  \"info\": \"Ruby gem bundler\",
+  \"homepage_uri\": \"https://bundler.io/\",
+  \"dependencies\": {
+    \"runtime\": []
+  },
+  \"licenses\": [\"MIT\"]
+}")
+
 (test-begin "gem")
 
 (test-assert "gem->guix-package"
@@ -50,8 +80,8 @@
          (lambda (url . rest)
            (match url
              ("https://rubygems.org/api/v1/gems/foo.json"
-              (values (open-input-string test-json)
-                      (string-length test-json)))
+              (values (open-input-string test-foo-json)
+                      (string-length test-foo-json)))
              (_ (error "Unexpected URL: " url)))))
     (match (gem->guix-package "foo")
       (('package
@@ -76,4 +106,76 @@
       (x
        (pk 'fail x #f)))))
 
+(test-assert "gem-recursive-import"
+  ;; Replace network resources with sample data.
+  (mock ((guix http-client) http-fetch
+         (lambda (url . rest)
+           (match url
+             ("https://rubygems.org/api/v1/gems/foo.json"
+              (values (open-input-string test-foo-json)
+                      (string-length test-foo-json)))
+             ("https://rubygems.org/api/v1/gems/bar.json"
+              (values (open-input-string test-bar-json)
+                      (string-length test-bar-json)))
+             ("https://rubygems.org/api/v1/gems/bundler.json"
+              (values (open-input-string test-bundler-json)
+                      (string-length test-bundler-json)))
+             (_ (error "Unexpected URL: " url)))))
+        (match (stream->list (gem-recursive-import "foo"))
+          ((('package
+              ('name "ruby-foo")
+              ('version "1.0.0")
+              ('source
+               ('origin
+                 ('method 'url-fetch)
+                 ('uri ('rubygems-uri "foo" 'version))
+                 ('sha256
+                  ('base32
+                   "1a270mlajhrmpqbhxcqjqypnvgrq4pgixpv3w9gwp1wrrapnwrzk"))))
+              ('build-system 'ruby-build-system)
+              ('propagated-inputs
+               ('quasiquote
+                (("bundler" ('unquote 'bundler))
+                 ("ruby-bar" ('unquote 'ruby-bar)))))
+              ('synopsis "A cool gem")
+              ('description "This package provides a cool gem")
+              ('home-page "https://example.com")
+              ('license ('list 'license:expat 'license:asl2.0)))
+            ('package
+              ('name "ruby-bundler")
+              ('version "1.14.2")
+              ('source
+               ('origin
+                 ('method 'url-fetch)
+                 ('uri ('rubygems-uri "bundler" 'version))
+                 ('sha256
+                  ('base32
+                   "1446xiz7zg0bz7kgx9jv84y0s4hpsg61dj5l3qb0i00avc1kxd9v"))))
+              ('build-system 'ruby-build-system)
+              ('synopsis "Ruby gem bundler")
+              ('description "Ruby gem bundler")
+              ('home-page "https://bundler.io/")
+              ('license 'license:expat))
+            ('package
+              ('name "ruby-bar")
+              ('version "1.0.0")
+              ('source
+               ('origin
+                 ('method 'url-fetch)
+                 ('uri ('rubygems-uri "bar" 'version))
+                 ('sha256
+                  ('base32
+                   "1a270mlajhrmpqbhxcqjqypnvgrq4pgixpv3w9gwp1wrrapnwrzk"))))
+              ('build-system 'ruby-build-system)
+              ('propagated-inputs
+               ('quasiquote
+                (('"bundler" ('unquote 'bundler)))))
+              ('synopsis "Another cool gem")
+              ('description "Another cool gem")
+              ('home-page "https://example.com")
+              ('license ('list 'license:expat 'license:asl2.0))))
+           #t)
+          (x
+           (pk 'fail x #f)))))
+
 (test-end "gem")