import: Add CHICKEN egg importer.

* guix/import/egg.scm: New file.
* guix/scripts/import/egg.scm: New file.
* tests/egg.scm: New file.
* Makefile.am (MODULES, SCM_TESTS): Register them.
* po/guix/POTFILES.in: Likewise.
* guix/scripts/import.scm (importers): Add egg importer.
* doc/guix.texi (Invoking guix import, Invoking guix refresh): Document it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

8 files changed, 623 insertions, 2 deletions

diff --git a/Makefile.am b/Makefile.am
index 8db7d6a320..3e72c3ebd0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -248,6 +248,7 @@ MODULES =					\
   guix/import/cpan.scm				\
   guix/import/cran.scm				\
   guix/import/crate.scm				\
+  guix/import/egg.scm   			\
   guix/import/elpa.scm   			\
   guix/import/gem.scm				\
   guix/import/github.scm   			\
@@ -293,6 +294,7 @@ MODULES =					\
   guix/scripts/challenge.scm			\
   guix/scripts/import/crate.scm			\
   guix/scripts/import/cran.scm			\
+  guix/scripts/import/egg.scm   		\
   guix/scripts/import/elpa.scm  		\
   guix/scripts/import/gem.scm			\
   guix/scripts/import/gnu.scm			\
@@ -449,6 +451,7 @@ SCM_TESTS =					\
   tests/debug-link.scm				\
   tests/derivations.scm			\
   tests/discovery.scm				\
+  tests/egg.scm				\
   tests/elpa.scm				\
   tests/file-systems.scm			\
   tests/gem.scm				\
diff --git a/doc/guix.texi b/doc/guix.texi
index 43198a0af1..ed442d3f9b 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -11600,6 +11600,28 @@ using this mode, the symbol of the package is made by appending the
 version to its name, so that multiple versions of the same package can
 coexist.
 @end table
+
+@item egg
+@cindex egg
+Import metadata for @uref{https://wiki.call-cc.org/eggs, CHICKEN eggs}.
+The information is taken from @file{PACKAGE.egg} files found in the
+@uref{git://code.call-cc.org/eggs-5-latest, eggs-5-latest} Git
+repository.  However, it does not provide all the information that we
+need, there is no ``description'' field, and the licenses used are not
+always precise (BSD is often used instead of BSD-N).
+
+@example
+guix import egg sourcehut
+@end example
+
+Additional options include:
+@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
 @end table
 
 The structure of the @command{guix import} code is modular.  It would be
@@ -11754,6 +11776,8 @@ the updater for KDE packages;
 the updater for X.org packages;
 @item kernel.org
 the updater for packages hosted on kernel.org;
+@item egg
+the updater for @uref{https://wiki.call-cc.org/eggs/, Egg} packages;
 @item elpa
 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
 @item cran
diff --git a/etc/news.scm b/etc/news.scm
index 65d83061df..f61c4d8ccf 100644
--- a/etc/news.scm
+++ b/etc/news.scm
@@ -14,6 +14,7 @@
 ;; Copyright © 2021 Zhu Zihao <all_but_last@163.com>
 ;; Copyright © 2021 Chris Marusich <cmmarusich@gmail.com>
 ;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
+;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
 ;;
 ;; Copying and distribution of this file, with or without modification, are
 ;; permitted in any medium without royalty provided the copyright notice and
diff --git a/guix/import/egg.scm b/guix/import/egg.scm
new file mode 100644
index 0000000000..26f8364732
--- /dev/null
+++ b/guix/import/egg.scm
@@ -0,0 +1,352 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
+;;;
+;;; 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 egg)
+  #:use-module (ice-9 ftw)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-71)
+  #:use-module (gcrypt hash)
+  #:use-module (guix git)
+  #:use-module (guix i18n)
+  #:use-module (guix base32)
+  #:use-module (guix diagnostics)
+  #:use-module (guix memoization)
+  #:use-module (guix packages)
+  #:use-module (guix upstream)
+  #:use-module (guix build-system)
+  #:use-module (guix build-system chicken)
+  #:use-module (guix store)
+  #:use-module ((guix download) #:select (download-to-store url-fetch))
+  #:use-module (guix import utils)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:export (egg->guix-package
+            egg-recursive-import
+            %egg-updater
+
+            ;; For tests.
+            guix-package->egg-name))
+
+;;; Commentary:
+;;;
+;;; (guix import egg) provides package importer for CHICKEN eggs.  See the
+;;; official specification format for eggs
+;;; <https://wiki.call-cc.org/man/5/Egg%20specification%20format>.
+;;;
+;;; The following happens under the hood:
+;;;
+;;; * <git://code.call-cc.org/eggs-5-latest> is a Git repository that contains
+;;;   the latest version of all CHICKEN eggs.  We look clone this repository
+;;;   and retrieve the latest version number, and the PACKAGE.egg file, which
+;;;   contains a list of lists containing metadata about the egg.
+;;;
+;;; * All the eggs are stored as tarballs at
+;;;   <https://code.call-cc.org/egg-tarballs/5>, so we grab the tarball for
+;;;   the egg from there.
+;;;
+;;; * The rest of the package fields will be parsed from the PACKAGE.egg file.
+;;;
+;;; Todos:
+;;;
+;;; * Support for CHICKEN 4?
+;;;
+;;; * Some packages will specify a specific version of a depencency in the
+;;;   PACKAGE.egg file, how should we handle this?
+;;;
+;;; Code:
+
+
+;;;
+;;; Egg metadata fetcher and helper functions.
+;;;
+
+(define package-name-prefix "chicken-")
+
+(define %eggs-url
+  (make-parameter "https://code.call-cc.org/egg-tarballs/5"))
+
+(define %eggs-home-page
+  (make-parameter "https://wiki.call-cc.org/egg"))
+
+(define (egg-source-url name version)
+  "Return the URL to the source tarball for version VERSION of the CHICKEN egg
+NAME."
+  (string-append (%eggs-url) "/" name "/" name "-" version ".tar.gz"))
+
+(define (egg-name->guix-name name)
+  "Return the package name for CHICKEN egg NAME."
+  (string-append package-name-prefix name))
+
+(define (eggs-repository)
+  "Update or fetch the latest version of the eggs repository and return the path
+to the repository."
+  (let* ((url "git://code.call-cc.org/eggs-5-latest")
+         (directory commit _ (update-cached-checkout url)))
+    directory))
+
+(define (egg-directory name)
+  "Return the directory containing the source code for the egg NAME."
+  (let ((eggs-directory (eggs-repository)))
+    (string-append eggs-directory "/" name)))
+
+(define (find-latest-version name)
+  "Get the latest version of the egg NAME."
+  (let ((directory (scandir (egg-directory name))))
+    (if directory
+        (last directory)
+        #f)))
+
+(define* (egg-metadata name #:optional file)
+  "Return the package metadata file for the egg NAME, or if FILE is specified,
+return the package metadata in FILE."
+  (call-with-input-file (or file
+                            (string-append (egg-directory name) "/"
+                                           (find-latest-version name)
+                                           "/" name ".egg"))
+    read))
+
+(define (guix-name->egg-name name)
+  "Return the CHICKEN egg name corresponding to the Guix package NAME."
+  (if (string-prefix? package-name-prefix name)
+      (string-drop name (string-length package-name-prefix))
+      name))
+
+(define (guix-package->egg-name package)
+  "Return the CHICKEN egg name of the Guix CHICKEN PACKAGE."
+  (or (assq-ref (package-properties package) 'upstream-name)
+      (guix-name->egg-name (package-name package))))
+
+(define (egg-package? package)
+  "Check if PACKAGE is an CHICKEN egg package."
+  (and (eq? (package-build-system package) chicken-build-system)
+       (string-prefix? package-name-prefix (package-name package))))
+
+(define string->license
+  ;; Doesn't seem to use a specific format.
+  ;; <https://wiki.call-cc.org/eggs-licensing>
+  (match-lambda
+   ("GPL-2" 'license:gpl2)
+   ("GPL-2+" 'license:gpl2+)
+   ("GPL-3" 'license:gpl3)
+   ("GPL-3+" 'license:gpl3+)
+   ("GPL" 'license:gpl?)
+   ("AGPL-3" 'license:agpl3)
+   ("AGPL" 'license:agpl?)
+   ("LGPL-2.0" 'license:lgpl2.0)
+   ("LGPL-2.0+" 'license:lgpl2.0+)
+   ("LGPL-2.1" 'license:lgpl2.1)
+   ("LGPL-2.1+" 'license:lgpl2.1+)
+   ("LGPL-3" 'license:lgpl3)
+   ("LGPL-3" 'license:lgpl3+)
+   ("LGPL" 'license:lgpl?)
+   ("BSD-1-Clause" 'license:bsd-1)
+   ("BSD-2-Clause" 'license:bsd-2)
+   ("BSD-3-Clause" 'license:bsd-3)
+   ("BSD" 'license:bsd?)
+   ("MIT" 'license:expat)
+   ("ISC" 'license:isc)
+   ("Artistic-2" 'license:artistic2.0)
+   ("Apache-2.0" 'license:asl2.0)
+   ("Public Domain" 'license:public-domain)
+   ((x) (string->license x))
+   ((lst ...) `(list ,@(map string->license lst)))
+   (_ #f)))
+
+
+;;;
+;;; Egg importer.
+;;;
+
+(define* (egg->guix-package name #:key (file #f) (source #f))
+  "Import CHICKEN egg NAME from and return a <package> record type for the
+egg, or #f on failure.  FILE is the filepath to the NAME.egg file.  SOURCE is
+the a ``file-like'' object containing the source code corresonding to the egg.
+If SOURCE is not specified, the tarball for the egg will be downloaded.
+
+Specifying the SOURCE argument is mainly useful for developing a CHICKEN egg
+locally.  Note that if FILE and SOURCE are specified, recursive import will
+not work."
+  (define egg-content (if file
+                          (egg-metadata name file)
+                          (egg-metadata name)))
+  (if (not egg-content)
+      (values #f '())                    ; egg doesn't exist
+      (let* ((version* (or (assoc-ref egg-content 'version)
+                           (find-latest-version name)))
+             (version (if (list? version*) (first version*) version*))
+             (source-url (if source #f (egg-source-url name version)))
+             (tarball (if source
+                          #f
+                          (with-store store
+                            (download-to-store store source-url)))))
+
+        (define egg-home-page
+          (string-append (%eggs-home-page) "/" name))
+
+        (define egg-synopsis
+          (match (assoc-ref egg-content 'synopsis)
+            ((synopsis) synopsis)
+            (_ #f)))
+
+        (define egg-licenses
+          (let ((licenses*
+                 (match (assoc-ref egg-content 'license)
+                   ((license)
+                    (map string->license (string-split license #\/)))
+                   (#f
+                    '()))))
+            (match licenses*
+              ((license) license)
+              ((license1 license2 ...) `(list ,@licenses*)))))
+
+        (define (maybe-symbol->string sym)
+          (if (symbol? sym) (symbol->string sym) sym))
+
+        (define (prettify-system-dependency name)
+          ;; System dependencies sometimes have spaces and/or upper case
+          ;; letters in them.
+          ;;
+          ;; There will probably still be some weird edge cases.
+          (string-map (lambda (char)
+                        (case char
+                          ((#\space) #\-)
+                          (else char)))
+                      (maybe-symbol->string name)))
+
+        (define* (egg-parse-dependency name #:key (system? #f))
+          (define extract-name
+            (match-lambda
+              ((name version) name)
+              (name name)))
+
+          (define (prettify-name name)
+            (if system?
+                (prettify-system-dependency name)
+                (maybe-symbol->string name)))
+          
+          (let ((name (prettify-name (extract-name name))))
+            ;; Dependencies are sometimes specified as symbols and sometimes
+            ;; as strings
+            (list (string-append (if system? "" package-name-prefix)
+                                 name)
+                  (list 'unquote
+                        (string->symbol (string-append
+                                         (if system? "" package-name-prefix)
+                                         name))))))
+
+        (define egg-propagated-inputs
+          (let ((dependencies (assoc-ref egg-content 'dependencies)))
+            (if (list? dependencies)
+                (map egg-parse-dependency
+                     dependencies)
+                '())))
+
+        ;; TODO: Or should these be propagated?
+        (define egg-inputs
+          (let ((dependencies (assoc-ref egg-content 'foreign-dependencies)))
+            (if (list? dependencies)
+                (map (lambda (name)
+                       (egg-parse-dependency name #:system? #t))
+                     dependencies)
+                '())))
+
+        (define egg-native-inputs
+          (let* ((test-dependencies (or (assoc-ref egg-content
+                                                   'test-dependencies)
+                                        '()))
+                 (build-dependencies (or (assoc-ref egg-content
+                                                    'build-dependencies)
+                                         '()))
+                 (test+build-dependencies (append test-dependencies
+                                                  build-dependencies)))
+            (match test+build-dependencies
+              ((_ _ ...) (map egg-parse-dependency
+                              test+build-dependencies))
+              (() '()))))
+
+        ;; Copied from (guix import hackage).
+        (define (maybe-inputs input-type inputs)
+          (match inputs
+            (()
+             '())
+            ((inputs ...)
+             (list (list input-type
+                         (list 'quasiquote inputs))))))
+
+        (values
+         `(package
+            (name ,(egg-name->guix-name name))
+            (version ,version)
+            (source
+             ,(if source
+                  source
+                  `(origin
+                     (method url-fetch)
+                     (uri ,source-url)
+                     (sha256
+                      (base32 ,(if tarball
+                                   (bytevector->nix-base32-string
+                                    (file-sha256 tarball))
+                                   "failed to download tar archive"))))))
+            (build-system chicken-build-system)
+            (arguments ,(list 'quasiquote (list #:egg-name name)))
+            ,@(maybe-inputs 'native-inputs egg-native-inputs)
+            ,@(maybe-inputs 'inputs egg-inputs)
+            ,@(maybe-inputs 'propagated-inputs egg-propagated-inputs)
+            (home-page ,egg-home-page)
+            (synopsis ,egg-synopsis)
+            (description #f)
+            (license ,egg-licenses))
+         (filter (lambda (name)
+                   (not (member name '("srfi-4"))))
+                 (map (compose guix-name->egg-name first)
+                      (append egg-propagated-inputs
+                              egg-native-inputs)))))))
+
+(define egg->guix-package/m                   ;memoized variant
+  (memoize egg->guix-package))
+
+(define (egg-recursive-import package-name)
+  (recursive-import package-name
+                    #:repo->guix-package (lambda* (name #:key version repo)
+                                           (egg->guix-package/m name))
+                    #:guix-name egg-name->guix-name))
+
+
+;;;
+;;; Updater.
+;;;
+
+(define (latest-release package)
+  "Return an @code{<upstream-source>} for the latest release of PACKAGE."
+  (let* ((egg-name (guix-package->egg-name package))
+         (version (find-latest-version egg-name))
+         (source-url (egg-source-url egg-name version)))
+    (upstream-source
+     (package (package-name package))
+     (version version)
+     (urls (list source-url)))))
+
+(define %egg-updater
+  (upstream-updater
+   (name 'egg)
+   (description "Updater for CHICKEN egg packages")
+   (pred egg-package?)
+   (latest latest-release)))
+
+;;; egg.scm ends here
diff --git a/guix/scripts/import.scm b/guix/scripts/import.scm
index bbd9a3b190..f53d1ac1f4 100644
--- a/guix/scripts/import.scm
+++ b/guix/scripts/import.scm
@@ -76,8 +76,8 @@ rather than \\n."
 ;;; Entry point.
 ;;;
 
-(define importers '("gnu" "pypi" "cpan" "hackage" "stackage" "elpa" "gem"
-                    "go" "cran" "crate" "texlive" "json" "opam"))
+(define importers '("gnu" "pypi" "cpan" "hackage" "stackage" "egg" "elpa"
+                    "gem" "go" "cran" "crate" "texlive" "json" "opam"))
 
 (define (resolve-importer name)
   (let ((module (resolve-interface
diff --git a/guix/scripts/import/egg.scm b/guix/scripts/import/egg.scm
new file mode 100644
index 0000000000..7dbd6fcd5a
--- /dev/null
+++ b/guix/scripts/import/egg.scm
@@ -0,0 +1,107 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
+;;;
+;;; 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 scripts import egg)
+  #:use-module (guix ui)
+  #:use-module (guix utils)
+  #:use-module (guix scripts)
+  #:use-module (guix import egg)
+  #:use-module (guix scripts import)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-11)
+  #:use-module (srfi srfi-37)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 format)
+  #:export (guix-import-egg))
+
+
+;;;
+;;; Command-line options.
+;;;
+
+(define %default-options
+  '())
+
+(define (show-help)
+  (display (G_ "Usage: guix import egg PACKAGE-NAME
+Import and convert the egg package for PACKAGE-NAME.\n"))
+  (display (G_ "
+  -h, --help             display this help and exit"))
+  (display (G_ "
+  -r, --recursive        import packages recursively"))
+  (display (G_ "
+  -V, --version          display version information and exit"))
+  (newline)
+  (show-bug-report-information))
+
+(define %options
+  ;; Specification of the command-line options.
+  (cons* (option '(#\h "help") #f #f
+                 (lambda args
+                   (show-help)
+                   (exit 0)))
+         (option '(#\V "version") #f #f
+                 (lambda args
+                   (show-version-and-exit "guix import egg")))
+         (option '(#\r "recursive") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'recursive #t result)))
+         %standard-import-options))
+
+
+;;;
+;;; Entry point.
+;;;
+
+(define (guix-import-egg . args)
+  (define (parse-options)
+    ;; Return the alist of option values.
+    (args-fold* args %options
+                (lambda (opt name arg result)
+                  (leave (G_ "~A: unrecognized option~%") name))
+                (lambda (arg result)
+                  (alist-cons 'argument arg result))
+                %default-options))
+
+  (let* ((opts (parse-options))
+         (repo (and=> (assoc-ref opts 'repo) string->symbol))
+         (args (filter-map (match-lambda
+                            (('argument . value)
+                             value)
+                            (_ #f))
+                           (reverse opts))))
+    (match args
+      ((package-name)
+       (if (assoc-ref opts 'recursive)
+           ;; Recursive import
+           (map (match-lambda
+                  ((and ('package ('name name) . rest) pkg)
+                   `(define-public ,(string->symbol name)
+                      ,pkg))
+                  (_ #f))
+                (egg-recursive-import package-name))
+           ;; Single import
+           (let ((sexp (egg->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 ...)
+       (leave (G_ "too many arguments~%"))))))
diff --git a/po/guix/POTFILES.in b/po/guix/POTFILES.in
index 727f820cca..14324b25de 100644
--- a/po/guix/POTFILES.in
+++ b/po/guix/POTFILES.in
@@ -7,6 +7,7 @@ gnu/system.scm
 gnu/services/shepherd.scm
 gnu/system/mapped-devices.scm
 gnu/system/shadow.scm
+guix/import/egg.scm
 guix/import/opam.scm
 gnu/installer.scm
 gnu/installer/connman.scm
@@ -100,6 +101,7 @@ guix/scripts/environment.scm
 guix/scripts/time-machine.scm
 guix/scripts/import/cpan.scm
 guix/scripts/import/crate.scm
+guix/scripts/import/egg.scm
 guix/scripts/import/gem.scm
 guix/scripts/import/gnu.scm
 guix/scripts/import/go.scm
diff --git a/tests/egg.scm b/tests/egg.scm
new file mode 100644
index 0000000000..0884d8d429
--- /dev/null
+++ b/tests/egg.scm
@@ -0,0 +1,132 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
+;;;
+;;; 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 (test-eggs)
+  #:use-module (guix import egg)
+  #:use-module (guix gexp)
+  #:use-module (guix base32)
+  #:use-module (gcrypt hash)
+  #:use-module (guix tests)
+  #:use-module ((guix build syscalls) #:select (mkdtemp!))
+  #:use-module ((guix build utils) #:select (delete-file-recursively mkdir-p which))
+  #:use-module ((guix utils) #:select (call-with-temporary-output-file))
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-64)
+  #:use-module (web uri)
+  #:use-module (ice-9 match))
+
+(define test-egg-1
+  '((synopsis "Example egg")
+    (license "GPL-3/MIT")
+    (version "1.0.0")
+    (test-dependencies test srfi-1)
+    (foreign-dependencies libgit2)
+    (build-dependencies begin-syntax)
+    (dependencies datatype)
+    (author "John Doe")))
+
+(define test-egg-2
+  '((synopsis "Example egg")
+    (license "GPL-3+")
+    (version "0.3")
+    (test-dependencies test)
+    (foreign-dependencies libgit2)
+    (build-dependencies begin-syntax)
+    (dependencies datatype)
+    (author "Alice Bobson")))
+
+(define test-egg-1-file "/tmp/guix-egg-1")
+(define test-egg-2-file "/tmp/guix-egg-2")
+
+(test-begin "egg")
+
+(test-equal "guix-package->egg-name"
+  "bar"
+  (guix-package->egg-name
+   (dummy-package "dummy"
+                  (name "chicken-bar"))))
+
+;; Copied from tests/hackage.scm
+(define-syntax-rule (define-package-matcher name pattern)
+  (define* (name obj)
+    (match obj
+      (pattern #t)
+      (x       (pk 'fail x #f)))))
+
+(define (eval-test-with-egg-file egg-name egg-test egg-file matcher)
+  (call-with-output-file egg-file
+    (lambda (port)
+      (write egg-test port)))
+  (matcher (egg->guix-package egg-name
+                              #:file egg-file
+                              #:source (plain-file
+                                        (string-append egg-name "-egg")
+                                        "content"))))
+
+(define-package-matcher match-chicken-foo
+  ('package
+    ('name "chicken-foo")
+    ('version "1.0.0")
+    ('source (? file-like? source))
+    ('build-system 'chicken-build-system)
+    ('arguments ('quasiquote ('#:egg-name "foo")))
+    ('native-inputs
+     ('quasiquote
+      (("chicken-test" ('unquote chicken-test))
+       ("chicken-srfi-1" ('unquote chicken-srfi-1))
+       ("chicken-begin-syntax" ('unquote chicken-begin-syntax)))))
+    ('inputs
+     ('quasiquote
+      (("libgit2" ('unquote libgit2)))))
+    ('propagated-inputs
+     ('quasiquote
+      (("chicken-datatype" ('unquote chicken-datatype)))))
+    ('home-page "https://wiki.call-cc.org/egg/foo")
+    ('synopsis "Example egg")
+    ('description #f)
+    ('license '(list license:gpl3 license:expat))))
+
+(define-package-matcher match-chicken-bar
+  ('package
+    ('name "chicken-bar")
+    ('version "0.3")
+    ('source (? file-like? source))
+    ('build-system 'chicken-build-system)
+    ('arguments ('quasiquote ('#:egg-name "bar")))
+    ('native-inputs
+     ('quasiquote
+      (("chicken-test" ('unquote chicken-test))
+       ("chicken-begin-syntax" ('unquote chicken-begin-syntax)))))
+    ('inputs
+     ('quasiquote
+      (("libgit2" ('unquote libgit2)))))
+    ('propagated-inputs
+     ('quasiquote
+      (("chicken-datatype" ('unquote chicken-datatype)))))
+    ('home-page "https://wiki.call-cc.org/egg/bar")
+    ('synopsis "Example egg")
+    ('description #f)
+    ('license 'license:gpl3+)))
+
+(test-assert "egg->guix-package local file, multiple licenses"
+  (eval-test-with-egg-file "foo" test-egg-1 test-egg-1-file match-chicken-foo))
+
+(test-assert "egg->guix-package local file, single license"
+  (eval-test-with-egg-file "bar" test-egg-2 test-egg-2-file match-chicken-bar))
+
+(test-end "egg")