summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Makefile.am3
-rw-r--r--doc/contributing.texi82
-rw-r--r--doc/guix.texi52
-rw-r--r--gnu/local.mk1
-rw-r--r--gnu/packages/elm.scm4
-rw-r--r--gnu/packages/patches/elm-offline-package-registry.patch71
-rw-r--r--guix/build-system/elm.scm172
-rw-r--r--guix/build/elm-build-system.scm380
-rw-r--r--tests/elm.scm97
9 files changed, 861 insertions, 1 deletions
diff --git a/Makefile.am b/Makefile.am
index 85a22be99c..9ca92c407c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -141,6 +141,7 @@ MODULES = \
guix/build-system/cmake.scm \
guix/build-system/dub.scm \
guix/build-system/dune.scm \
+ guix/build-system/elm.scm \
guix/build-system/emacs.scm \
guix/build-system/font.scm \
guix/build-system/go.scm \
@@ -192,6 +193,7 @@ MODULES = \
guix/build/cmake-build-system.scm \
guix/build/dub-build-system.scm \
guix/build/dune-build-system.scm \
+ guix/build/elm-build-system.scm \
guix/build/emacs-build-system.scm \
guix/build/meson-build-system.scm \
guix/build/minify-build-system.scm \
@@ -472,6 +474,7 @@ SCM_TESTS = \
tests/derivations.scm \
tests/discovery.scm \
tests/egg.scm \
+ tests/elm.scm \
tests/elpa.scm \
tests/file-systems.scm \
tests/gem.scm \
diff --git a/doc/contributing.texi b/doc/contributing.texi
index 862dcbf12a..555b9bb961 100644
--- a/doc/contributing.texi
+++ b/doc/contributing.texi
@@ -447,6 +447,7 @@ needed is to review and apply the patch.
* Perl Modules:: Little pearls.
* Java Packages:: Coffee break.
* Rust Crates:: Beware of oxidation.
+* Elm Packages:: Trees of browser code
* Fonts:: Fond of fonts.
@end menu
@@ -898,6 +899,87 @@ developed for a different Operating System, depend on features from the Nightly
Rust compiler, or the test suite may have atrophied since it was released.
+@node Elm Packages
+@subsection Elm Packages
+
+@cindex Elm
+Elm applications can be named like other software: their names need not
+mention Elm.
+
+Packages in the Elm sense (see @code{elm-build-system} under @ref{Build
+Systems}) are required use names of the format
+@var{author}@code{/}@var{project}, where both the @var{author} and the
+@var{project} may contain hyphens internally, and the @var{author} sometimes
+contains uppercase letters.
+
+To form the Guix package name from the upstream name, we follow a convention
+similar to Python packages (@pxref{Python Modules}), adding an @code{elm-}
+prefix unless the name would already begin with @code{elm-}.
+
+In many cases we can reconstruct an Elm package's upstream name heuristically,
+but, since conversion to a Guix-style name involves a loss of information,
+this is not always possible. Care should be taken to add the
+@code{'upstream-name} property when necessary so that tools
+will work correctly. The most notable scenarios
+when explicitly specifying the upstream name is necessary are:
+
+@enumerate
+@item
+When the @var{author} is @code{elm} and the @var{project} contains one or more
+hyphens, as with @code{elm/virtual-dom}; and
+
+@item
+When the @var{author} contains hyphens or uppercase letters, as with
+@code{Elm-Canvas/raster-shapes}---unless the @var{author} is
+@code{elm-explorations}, which is handled as a special case, so packages like
+@code{elm-explorations/markdown} do @emph{not} need to use the
+@code{'upstream-name} property.
+@end enumerate
+
+The module @code{(guix build-system elm)} provides the following utilities for
+working with names and related conventions:
+
+@deffn {Scheme procedure} elm-package-origin @var{elm-name} @var{version} @
+ @var{hash}
+Returns a Git origin using the repository naming and tagging regime required
+for a published Elm package with the upstream name @var{elm-name} at version
+@var{version} with sha256 checksum @var{hash}.
+
+For example:
+@lisp
+(package
+ (name "elm-html")
+ (version "1.0.0")
+ (source
+ (elm-package-origin
+ "elm/html"
+ version
+ (base32 "15k1679ja57vvlpinpv06znmrxy09lbhzfkzdc89i01qa8c4gb4a")))
+ ...)
+@end lisp
+@end deffn
+
+@deffn {Scheme procedure} elm->package-name @var{elm-name}
+Returns the Guix-style package name for an Elm package with upstream name
+@var{elm-name}.
+
+Note that there is more than one possible @var{elm-name} for which
+@code{elm->package-name} will produce a given result.
+@end deffn
+
+@deffn {Scheme procedure} guix-package->elm-name @var{package}
+Given an Elm @var{package}, returns the possibly-inferred upstream name, or
+@code{#f} the upstream name is not specified via the @code{'upstream-name}
+property and can not be inferred by @code{infer-elm-package-name}.
+@end deffn
+
+@deffn {Scheme procedure} infer-elm-package-name @var{guix-name}
+Given the @var{guix-name} of an Elm package, returns the inferred upstream
+name, or @code{#f} if the upstream name can't be inferred. If the result is
+not @code{#f}, supplying it to @code{elm->package-name} would produce
+@var{guix-name}.
+@end deffn
+
@node Fonts
@subsection Fonts
diff --git a/doc/guix.texi b/doc/guix.texi
index faa35060ef..3eff660f0e 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -102,6 +102,7 @@ Copyright @copyright{} 2021 Sarah Morgensen@*
Copyright @copyright{} 2021 Josselin Poiret@*
Copyright @copyright{} 2022 Remco van 't Veer@*
Copyright @copyright{} 2022 Aleksandr Vityazev@*
+Copyright @copyright{} 2022 Philip M@sup{c}Grath@*
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -8717,6 +8718,57 @@ only one of them. This is equivalent to passing the @code{-p} argument to
@end defvr
+@defvr {Scheme variable} elm-build-system
+This variable is exported by @code{(guix build-system elm)}. It implements a
+build procedure for @url{https://elm-lang.org, Elm} packages similar to
+@samp{elm install}.
+
+The build system adds an Elm compiler package to the set of inputs. The
+default compiler package (currently @code{elm}) can be overridden
+using the @code{#:elm} argument. Additionally, Elm packages needed by the
+build system itself are added as implicit inputs if they are not already
+present: to suppress this behavior, use the
+@code{#:implicit-elm-package-inputs?} argument, which is primarily useful for
+bootstrapping.
+
+The @code{"dependencies"} and @code{"test-dependencies"} in an Elm package's
+@file{elm.json} file correspond to @code{propagated-inputs} and @code{inputs},
+respectively.
+
+Elm requires a particular structure for package names: @pxref{Elm Packages}
+for more details, including utilities provided by @code{(guix build-system
+elm)}.
+
+There are currently a few noteworthy limitations to @code{elm-build-system}:
+
+@itemize
+@item
+The build system is focused on @dfn{packages} in the Elm sense of the word:
+Elm @dfn{projects} which declare @code{@{ "type": "package" @}} in their
+@file{elm.json} files. Using @code{elm-build-system} to build Elm
+@dfn{applications} (which declare @code{@{ "type": "application" @}}) is
+possible, but requires ad-hoc modifications to the build phases.
+
+@item
+Elm supports multiple versions of a package coexisting simultaneously under
+@env{ELM_HOME}, but this does not yet work well with @code{elm-build-system}.
+This limitation primarily affects Elm applications, because they specify
+exact versions for their dependencies, whereas Elm packages specify supported
+version ranges. As a workaround, you can use
+the @code{patch-application-dependencies} procedure provided by
+@code{(guix build elm-build-system)} to rewrite their @file{elm.json} files to
+refer to the package versions actually present in the build environment.
+Alternatively, Guix package transformations (@pxref{Defining Package
+Variants}) could be used to rewrite an application's entire dependency graph.
+
+@item
+We are not yet able to run tests for Elm projects because neither
+@url{https://github.com/mpizenberg/elm-test-rs, @command{elm-test-rs}} nor the
+Node.js-based @url{https://github.com/rtfeldman/node-test-runner,
+@command{elm-test}} runner has been packaged for Guix yet.
+@end itemize
+@end defvr
+
@defvr {Scheme Variable} go-build-system
This variable is exported by @code{(guix build-system go)}. It
implements a build procedure for Go packages using the standard
diff --git a/gnu/local.mk b/gnu/local.mk
index 70efa16c63..6274f43566 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1024,6 +1024,7 @@ dist_patch_DATA = \
%D%/packages/patches/einstein-build.patch \
%D%/packages/patches/elfutils-tests-ptrace.patch \
%D%/packages/patches/elixir-path-length.patch \
+ %D%/packages/patches/elm-offline-package-registry.patch \
%D%/packages/patches/elm-reactor-static-files.patch \
%D%/packages/patches/elogind-revert-polkit-detection.patch \
%D%/packages/patches/emacs-exec-path.patch \
diff --git a/gnu/packages/elm.scm b/gnu/packages/elm.scm
index a3863e6e6f..35bdcc65f5 100644
--- a/gnu/packages/elm.scm
+++ b/gnu/packages/elm.scm
@@ -25,6 +25,7 @@
#:use-module (gnu packages haskell-xyz)
#:use-module (gnu packages haskell-web)
#:use-module (guix build-system haskell)
+ #:use-module (guix build-system elm)
#:use-module (guix gexp)
#:use-module (guix git-download)
#:use-module ((guix licenses) #:prefix license:)
@@ -53,7 +54,8 @@
(sha256
(base32 "1rdg3xp3js9xadclk3cdypkscm5wahgsfmm4ldcw3xswzhw6ri8w"))
(patches
- (search-patches "elm-reactor-static-files.patch"))))
+ (search-patches "elm-reactor-static-files.patch"
+ "elm-offline-package-registry.patch"))))
(build-system haskell-build-system)
(arguments
(list
diff --git a/gnu/packages/patches/elm-offline-package-registry.patch b/gnu/packages/patches/elm-offline-package-registry.patch
new file mode 100644
index 0000000000..761ec69878
--- /dev/null
+++ b/gnu/packages/patches/elm-offline-package-registry.patch
@@ -0,0 +1,71 @@
+From 06563409e6f2b1cca7bc1b27e31efd07a7569da8 Mon Sep 17 00:00:00 2001
+From: Philip McGrath <philip@philipmcgrath.com>
+Date: Thu, 14 Apr 2022 22:41:04 -0400
+Subject: [PATCH] minimal support for offline builds
+
+Normally, Elm performs HTTP requests before building to obtain or
+update its list of all registed packages and their versions.
+This is problematic in the Guix build environment.
+
+This patch causes Elm to check if the `GUIX_ELM_OFFLINE_REGISTRY_FILE`
+is set and, if so, to use the contents of the file it specifies as
+though it were the response from
+https://package.elm-lang.org/all-packages.
+
+This patch does not attempt to add more general support for offline
+builds. In particular, it does not attempt to support incremental
+updates to the package registry cache file. See also discussion at
+https://discourse.elm-lang.org/t/private-package-tool-spec/6779/25.
+---
+ builder/src/Deps/Registry.hs | 25 +++++++++++++++++++++----
+ 1 file changed, 21 insertions(+), 4 deletions(-)
+
+diff --git a/builder/src/Deps/Registry.hs b/builder/src/Deps/Registry.hs
+index 8d7def98..70cf3622 100644
+--- a/builder/src/Deps/Registry.hs
++++ b/builder/src/Deps/Registry.hs
+@@ -18,6 +18,8 @@ import Control.Monad (liftM2)
+ import Data.Binary (Binary, get, put)
+ import qualified Data.List as List
+ import qualified Data.Map.Strict as Map
++import System.Environment as Env
++import qualified Data.ByteString as BS
+
+ import qualified Deps.Website as Website
+ import qualified Elm.Package as Pkg
+@@ -190,13 +192,28 @@ getVersions' name (Registry _ versions) =
+ post :: Http.Manager -> String -> D.Decoder x a -> (a -> IO b) -> IO (Either Exit.RegistryProblem b)
+ post manager path decoder callback =
+ let
+- url = Website.route path []
+- in
+- Http.post manager url [] Exit.RP_Http $
+- \body ->
++ mkBodyCallback url body =
+ case D.fromByteString decoder body of
+ Right a -> Right <$> callback a
+ Left _ -> return $ Left $ Exit.RP_Data url body
++ postOnline url cb =
++ Http.post manager url [] Exit.RP_Http cb
++ performPost f url =
++ f url (mkBodyCallback url)
++ in
++ do
++ maybeFile <- Env.lookupEnv "GUIX_ELM_OFFLINE_REGISTRY_FILE"
++ case (path, maybeFile) of
++ ( "/all-packages", Just file ) ->
++ performPost postOffline file
++ ( _, _ ) ->
++ -- don't know how to handle other endpoints yet
++ performPost postOnline (Website.route path [])
++
++postOffline :: String -> (BS.ByteString -> IO a) -> IO a
++postOffline file callback = do
++ body <- BS.readFile file
++ callback body
+
+
+
+--
+2.32.0
+
diff --git a/guix/build-system/elm.scm b/guix/build-system/elm.scm
new file mode 100644
index 0000000000..b54954bf4e
--- /dev/null
+++ b/guix/build-system/elm.scm
@@ -0,0 +1,172 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Philip McGrath <philip@philipmcgrath.com>
+;;;
+;;; 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 build-system elm)
+ #:use-module (guix store)
+ #:use-module (guix utils)
+ #:use-module (guix packages)
+ #:use-module (guix gexp)
+ #:use-module (guix monads)
+ #:use-module (guix search-paths)
+ #:use-module (guix git-download)
+ #:use-module (guix build-system)
+ #:use-module (guix build-system gnu)
+ #:use-module (ice-9 match)
+ #:use-module (srfi srfi-1)
+ #:export (elm->package-name
+ guix-package->elm-name
+ infer-elm-package-name
+ elm-package-origin
+ %elm-build-system-modules
+ %elm-default-modules
+ elm-build
+ elm-build-system))
+
+(define (elm->package-name name)
+ "Given the NAME of an Elm package, return a Guix-style package name."
+ (let ((converted
+ (string-join (string-split (string-downcase name) #\/) "-")))
+ (if (string-prefix? "elm-" converted)
+ converted
+ (string-append "elm-" converted))))
+
+(define (guix-package->elm-name package)
+ "Given an Elm PACKAGE, return the possibly-inferred upstream name, or #f the
+upstream name is not specified and can't be inferred."
+ (or (assoc-ref (package-properties package) 'upstream-name)
+ (infer-elm-package-name (package-name package))))
+
+(define (infer-elm-package-name guix-name)
+ "Given the GUIX-NAME of an Elm package, return the inferred upstream name,
+or #f if it can't be inferred. If the result is not #f, supplying it to
+'elm->package-name' would produce GUIX-NAME.
+
+See also 'guix-package->elm-name', which respects the 'upstream-name'
+property."
+ (define (parts-join part0 parts)
+ (string-join (cons part0 parts) "-"))
+ (match (string-split guix-name #\-)
+ (("elm" "explorations" part0 parts ...)
+ (string-append "elm-explorations/"
+ (parts-join part0 parts)))
+ (("elm" owner part0 parts ...)
+ (string-append owner "/" (parts-join part0 parts)))
+ (("elm" repo)
+ (string-append "elm/" repo))
+ (_
+ #f)))
+
+(define (elm-package-origin elm-name version hash)
+ "Return an origin for the Elm package with upstream name ELM-NAME at the
+given VERSION with sha256 checksum HASH."
+ ;; elm requires this very specific repository structure and tagging regime
+ (origin
+ (method git-fetch)
+ (uri (git-reference
+ (url (string-append "https://github.com/" elm-name))
+ (commit version)))
+ (file-name (git-file-name (elm->package-name elm-name) version))
+ (sha256 hash)))
+
+(define %elm-build-system-modules
+ ;; Build-side modules imported by default.
+ `((guix build elm-build-system)
+ (guix build json)
+ (guix build union)
+ ,@%gnu-build-system-modules))
+
+(define %elm-default-modules
+ ;; Modules in scope in the build-side environment.
+ '((guix build elm-build-system)
+ (guix build utils)
+ (guix build json)
+ (guix build union)))
+
+(define (default-elm)
+ "Return the default Elm package for builds."
+ ;; Lazily resolve the binding to avoid a circular dependency.
+ (let ((elm (resolve-interface '(gnu packages elm))))
+ (module-ref elm 'elm)))
+
+(define* (lower name
+ #:key source inputs native-inputs outputs system target
+ (implicit-elm-package-inputs? #t)
+ (elm (default-elm))
+ #:allow-other-keys
+ #:rest arguments)
+ "Return a bag for NAME."
+ (define private-keywords
+ '(#:target #:implicit-elm-package-inputs? #:elm #:inputs #:native-inputs))
+ (cond
+ (target
+ ;; Cross-compilation is not yet supported. It should be easy, though,
+ ;; since the build products are all platform-independent.
+ #f)
+ (else
+ (bag
+ (name name)
+ (system system)
+ (host-inputs
+ `(,@(if source
+ `(("source" ,source))
+ '())
+ ,@inputs
+ ("elm" ,elm)
+ ;; TODO: probably don't need most of (standard-packages)
+ ,@(standard-packages)))
+ (outputs outputs)
+ (build elm-build)
+ (arguments (strip-keyword-arguments private-keywords arguments))))))
+
+(define* (elm-build name inputs
+ #:key
+ source
+ (tests? #t)
+ (phases '%standard-phases)
+ (outputs '("out"))
+ (search-paths '())
+ (system (%current-system))
+ (guile #f)
+ (imported-modules %elm-build-system-modules)
+ (modules %elm-default-modules))
+ "Build SOURCE using ELM."
+ (define builder
+ (with-imported-modules imported-modules
+ #~(begin
+ (use-modules #$@(sexp->gexp modules))
+ (elm-build #:name #$name
+ #:source #+source
+ #:system #$system
+ #:tests? #$tests?
+ #:phases #$phases
+ #:outputs #$(outputs->gexp outputs)
+ #:search-paths '#$(sexp->gexp
+ (map search-path-specification->sexp
+ search-paths))
+ #:inputs #$(input-tuples->gexp inputs)))))
+ (mlet %store-monad ((guile (package->derivation (or guile (default-guile))
+ system #:graft? #f)))
+ (gexp->derivation name builder
+ #:system system
+ #:guile-for-build guile)))
+
+(define elm-build-system
+ (build-system
+ (name 'elm)
+ (description "The Elm build system")
+ (lower lower)))
diff --git a/guix/build/elm-build-system.scm b/guix/build/elm-build-system.scm
new file mode 100644
index 0000000000..02d7c029dd
--- /dev/null
+++ b/guix/build/elm-build-system.scm
@@ -0,0 +1,380 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Philip McGrath <philip@philipmcgrath.com>
+;;;
+;;; 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 build elm-build-system)
+ #:use-module ((guix build gnu-build-system) #:prefix gnu:)
+ #:use-module (guix build utils)
+ #:use-module (guix build json)
+ #:use-module (guix build union)
+ #:use-module (ice-9 ftw)
+ #:use-module (ice-9 rdelim)
+ #:use-module (ice-9 regex)
+ #:use-module (ice-9 match)
+ #:use-module (ice-9 popen)
+ #:use-module (ice-9 vlist)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:use-module (srfi srfi-71)
+ #:export (%standard-phases
+ patch-application-dependencies
+ patch-json-string-escapes
+ read-offline-registry->vhash
+ elm-build))
+
+;;; Commentary:
+;;;
+;;; Elm draws a sharp distinction between "projects" with `{"type":"package"}`
+;;; vs. `{"type":"application"}` in the "elm.json" file: see
+;;; <https://github.com/elm/compiler/blob/master/docs/elm.json/package.md> and
+;;; <https://github.com/elm/compiler/blob/master/docs/elm.json/application.md>.
+;;; For now, `elm-build-system` is designed for "package"s: packaging
+;;; "application"s requires ad-hoc replacements for some phases---but see
+;;; `patch-application-dependencies`, which helps to work around a known issue
+;;; discussed below. It would be nice to add more streamlined support for
+;;; "application"s one we have more experience building them in Guix. For
+;;; example, we could incorporate the `uglifyjs` advice from
+;;; <https://github.com/elm/compiler/blob/master/hints/optimize.md>.
+;;;
+;;; We want building an Elm "package" to produce:
+;;;
+;;; - a "docs.json" file with extracted documentation; and
+;;;
+;;; - an "artifacts.dat" file with compilation results for use in building
+;;; "package"s and "application"s.
+;;;
+;;; Unfortunately, there isn't an entry point to the Elm compiler that builds
+;;; those files directly. Building with `elm make` does something different,
+;;; more oriented toward development, testing, and building "application"s.
+;;; We work around this limitation by staging the "package" we're building as
+;;; though it were already installed in ELM_HOME, generating a trivial Elm
+;;; "application" that depends on the "package", and building the
+;;; "application", which causes the files for the "package" to be built.
+;;;
+;;; Much of the ceremony involved is to avoid using `elm` in ways that would
+;;; make it try to do network IO beyond the bare minimum functionality for
+;;; which we've patched a replacement into our `elm`. On the other hand, we
+;;; get to take advantage of the very regular structure required of Elm
+;;; packages.
+;;;
+;;; *Known issue:* Elm itself supports multiple versions of "package"s
+;;; coexisting simultaneously under ELM_HOME, but we do not support this yet.
+;;; Sometimes, parallel versions coexisting causes `elm` to try to write to
+;;; built "artifacts.dat" files. For now, two workarounds are possible:
+;;;
+;;; - Use `patch-application-dependencies` to rewrite an "application"'s
+;;; "elm.json" file to refer to the versions of its inputs actually
+;;; packaged in Guix.
+;;;
+;;; - Use a Guix package transformation to rewrite your "application"'s
+;;; dependencies recursively, so that only one version of each Elm
+;;; "package" is included in your "application"'s build environment.
+;;;
+;;; Patching `elm` more extensively---perhaps adding an `elm guix`
+;;; subcommand`---might let us address these issues more directly.
+;;;
+;;; Code:
+;;;
+
+(define %essential-elm-packages
+ ;; elm/json isn't essential in a fundamental sense,
+ ;; but it's required for a {"type":"application"},
+ ;; which we are generating to trigger the build
+ '("elm/core" "elm/json"))
+
+(define* (target-elm-version #:optional elm)
+ "Return the version of ELM or whichever 'elm' is in $PATH.
+Return #false if it cannot be determined."
+ (let* ((pipe (open-pipe* OPEN_READ
+ (or elm "elm")
+ "--version"))
+ (line (read-line pipe)))
+ (and (zero? (close-pipe pipe))
+ (string? line)
+ line)))
+
+(define* (prepare-elm-home #:key native-inputs inputs #:allow-other-keys)
+ "Set the ELM_HOME environment variable and populate the indicated directory
+with the union of the Elm \"package\" inputs. Also, set GUIX_ELM_VERSION to
+the version of the Elm compiler in use."
+ (let* ((elm (search-input-file (or native-inputs inputs) "/bin/elm"))
+ (elm-version (target-elm-version elm)))
+ (setenv "GUIX_ELM_VERSION" elm-version)
+ (mkdir "../elm-home")
+ (with-directory-excursion "../elm-home"
+ (union-build elm-version
+ (search-path-as-list
+ (list (string-append "share/elm/" elm-version))
+ (map cdr inputs))
+ #:create-all-directories? #t)
+ (setenv "ELM_HOME" (getcwd)))))
+
+(define* (stage #:key native-inputs inputs #:allow-other-keys)
+ "Extract the installable files from the Elm \"package\" into a staging
+directory and link it into the ELM_HOME tree. Also, set GUIX_ELM_PKG_NAME and
+GUIX_ELM_PKG_VERSION to the name and version, respectively, of the Elm package
+being built, as defined in its \"elm.json\" file."
+ (let* ((elm-version (getenv "GUIX_ELM_VERSION"))
+ (elm-home (getenv "ELM_HOME"))
+ (info (match (call-with-input-file "elm.json" read-json)
+ (('@ . alist) alist)))
+ (name (assoc-ref info "name"))
+ (version (assoc-ref info "version"))
+ (rel-dir (string-append elm-version "/packages/" name "/" version))
+ (staged-dir (string-append elm-home "/../staged/" rel-dir)))
+ (setenv "GUIX_ELM_PKG_NAME" name)
+ (setenv "GUIX_ELM_PKG_VERSION" version)
+ (mkdir-p staged-dir)
+ (mkdir-p (string-append elm-home "/" (dirname rel-dir)))
+ (symlink staged-dir
+ (string-append elm-home "/" rel-dir))
+ (copy-recursively "src" (string-append staged-dir "/src"))
+ (install-file "elm.json" staged-dir)
+ (install-file "README.md" staged-dir)
+ (when (file-exists? "LICENSE")
+ (install-file "LICENSE" staged-dir))))
+
+(define (patch-json-string-escapes file)
+ "Work around a bug in the Elm compiler's JSON parser by attempting to
+replace REVERSE-SOLIDUS--SOLIDUS escape sequences in FILE with unescaped
+SOLIDUS characters."
+ ;; https://github.com/elm/compiler/issues/2255
+ (substitute* file
+ (("\\\\/")
+ "/")))
+
+(define (directory-list dir)
+ "Like DIRECTORY-LIST from 'racket/base': lists the contents of DIR, not
+including the special \".\" and \"..\" entries."
+ (scandir dir (lambda (f)
+ (not (member f '("." ".."))))))
+
+(define* (make-offline-registry-file #:key inputs #:allow-other-keys)
+ "Generate an \"offline-package-registry.json\" file and set
+GUIX_ELM_OFFLINE_REGISTRY_FILE to its path, cooperating with a patch to `elm`
+to avoid attempting to download a list of all published Elm package names and
+versions from the internet."
+ (let* ((elm-home (getenv "ELM_HOME"))
+ (elm-version (getenv "GUIX_ELM_VERSION"))
+ (registry-file
+ (string-append elm-home "/../offline-package-registry.json"))
+ (registry-alist
+ ;; here, we don't need to look up entries, so we build the
+ ;; alist directly, rather than using a vhash
+ (with-directory-excursion
+ (string-append elm-home "/" elm-version "/packages")
+ (append-map (lambda (org)
+ (with-directory-excursion org
+ (map (lambda (repo)
+ (cons (string-append org "/" repo)
+ (directory-list repo)))
+ (directory-list "."))))
+ (directory-list ".")))))
+ (call-with-output-file registry-file
+ (lambda (out)
+ (write-json `(@ ,@registry-alist) out)))
+ (patch-json-string-escapes registry-file)
+ (setenv "GUIX_ELM_OFFLINE_REGISTRY_FILE" registry-file)))
+
+(define (read-offline-registry->vhash)
+ "Return a vhash mapping Elm \"package\" names to lists of available version
+strings."
+ (alist->vhash
+ (match (call-with-input-file (getenv "GUIX_ELM_OFFLINE_REGISTRY_FILE")
+ read-json)
+ (('@ . alist) alist))))
+
+(define (find-indirect-dependencies registry-vhash root-pkg root-version)
+ "Return the recursive dependencies of ROOT-PKG, an Elm \"package\" name, at
+version ROOT-VERSION as an alist mapping Elm \"package\" names to (single)
+versions. The resulting alist will not include entries for
+%ESSENTIAL-ELM-PACKAGES or for ROOT-PKG itself. The REGISTRY-VHASH is used in
+conjunction with the ELM_HOME environment variable to find dependencies."
+ (with-directory-excursion
+ (string-append (getenv "ELM_HOME")
+ "/" (getenv "GUIX_ELM_VERSION")
+ "/packages")
+ (define (get-dependencies pkg version acc)
+ (let* ((elm-json-alist
+ (match (call-with-input-file
+ (string-append pkg "/" version "/elm.json")
+ read-json)
+ (('@ . alist) alist)))
+ (deps-alist
+ (match (assoc-ref elm-json-alist "dependencies")
+ (('@ . alist) alist)))
+ (deps-names
+ (filter-map (match-lambda
+ ((name . range)
+ (and (not (member name %essential-elm-packages))
+ name)))
+ deps-alist)))
+ (fold register-dependency acc deps-names)))
+ (define (register-dependency pkg acc)
+ ;; Using vhash-cons unconditionally would add duplicate entries,
+ ;; which would then cause problems when we must emit JSON.
+ ;; Plus, we can avoid needlessly duplicating work.
+ (if (vhash-assoc pkg acc)
+ acc
+ (match (vhash-assoc pkg registry-vhash)
+ ((_ version . _)
+ ;; in the rare case that multiple versions are present,
+ ;; just picking an arbitrary one seems to work well enough for now
+ (get-dependencies pkg version (vhash-cons pkg version acc))))))
+ (vlist->list
+ (get-dependencies root-pkg root-version vlist-null))))
+
+(define* (patch-application-dependencies #:key inputs #:allow-other-keys)
+ "Rewrites the \"elm.json\" file in the working directory---which must be of
+`\"type\":\"application\"`, not `\"type\":\"package\"`---to refer to the
+dependency versions actually provided via Guix. The
+GUIX_ELM_OFFLINE_REGISTRY_FILE environment variable is used to find available
+versions."
+ (let* ((registry-vhash (read-offline-registry->vhash))
+ (rewrite-dep-version
+ (match-lambda
+ ((name . _)
+ (cons name (match (vhash-assoc name registry-vhash)
+ ((_ version) ;; no dot
+ version))))))
+ (rewrite-direct/indirect
+ (match-lambda
+ ;; a little checking to avoid confusing misuse with "package"
+ ;; project dependencies, which have a different shape
+ (((and key (or "direct" "indirect"))
+ '@ . alist)
+ `(,key @ ,@(map rewrite-dep-version alist)))))
+ (rewrite-json-section
+ (match-lambda
+ (((and key (or "dependencies" "test-dependencies"))
+ '@ . alist)
+ `(,key @ ,@(map rewrite-direct/indirect alist)))
+ ((k . v)
+ (cons k v))))
+ (rewrite-elm-json
+ (match-lambda
+ (('@ . alist)
+ `(@ ,@(map rewrite-json-section alist))))))
+ (with-atomic-file-replacement "elm.json"
+ (lambda (in out)
+ (write-json (rewrite-elm-json (read-json in))
+ out)))
+ (patch-json-string-escapes "elm.json")))
+
+(define* (configure #:key native-inputs inputs #:allow-other-keys)
+ "Generate a trivial Elm \"application\" with a direct dependency on the Elm
+\"package\" currently being built."
+ (let* ((info (match (call-with-input-file "elm.json" read-json)
+ (('@ . alist) alist)))
+ (name (getenv "GUIX_ELM_PKG_NAME"))
+ (version (getenv "GUIX_ELM_PKG_VERSION"))
+ (elm-home (getenv "ELM_HOME"))
+ (registry-vhash (read-offline-registry->vhash))
+ (app-dir (string-append elm-home "/../fake-app")))
+ (mkdir-p (string-append app-dir "/src"))
+ (with-directory-excursion app-dir
+ (call-with-output-file "elm.json"
+ (lambda (out)
+ (write-json
+ `(@ ("type" . "application")
+ ("source-directories" "src") ;; intentionally no dot
+ ("elm-version" . ,(getenv "GUIX_ELM_VERSION"))
+ ("dependencies"
+ @ ("direct"
+ @ ,@(map (lambda (pkg)
+ (match (vhash-assoc pkg registry-vhash)
+ ((_ pkg-version . _)
+ (cons pkg
+ (if (equal? pkg name)
+ version
+ pkg-version)))))
+ (if (member name %essential-elm-packages)
+ %essential-elm-packages
+ (cons name %essential-elm-packages))))
+ ("indirect"
+ @ ,@(if (member name %essential-elm-packages)
+ '()
+ (find-indirect-dependencies registry-vhash
+ name
+ version))))
+ ("test-dependencies"
+ @ ("direct" @)
+ ("indirect" @)))
+ out)))
+ (patch-json-string-escapes "elm.json")
+ (with-output-to-file "src/Main.elm"
+ ;; the most trivial possible elm program
+ (lambda ()
+ (display "module Main exposing (..)
+main : Program () () ()
+main = Platform.worker
+ { init = \\_ -> ( (), Cmd.none )
+ , update = \\_ -> \\_ -> ( (), Cmd.none )
+ , subscriptions = \\_ -> Sub.none }"))))))
+
+(define* (build #:key native-inputs inputs #:allow-other-keys)
+ "Run `elm make` to build the Elm \"application\" generated by CONFIGURE."
+ (with-directory-excursion (string-append (getenv "ELM_HOME") "/../fake-app")
+ (invoke (search-input-file (or native-inputs inputs) "/bin/elm")
+ "make"
+ "src/Main.elm")))
+
+(define* (check #:key tests? #:allow-other-keys)
+ "Does nothing, because the `elm-test` executable has not yet been packaged
+for Guix."
+ (when tests?
+ (display "elm-test has not yet been packaged for Guix\n")))
+
+(define* (install #:key outputs #:allow-other-keys)
+ "Installs the contents of the directory generated by STAGE, including any
+files added by BUILD, to the Guix package output."
+ (copy-recursively
+ (string-append (getenv "ELM_HOME") "/../staged")
+ (string-append (assoc-ref outputs "out") "/share/elm")))
+
+(define* (validate-compiled #:key outputs #:allow-other-keys)
+ "Checks that the files \"artifacts.dat\" and \"docs.json\" have been
+installed."
+ (let ((base (string-append "/share/elm/"
+ (getenv "GUIX_ELM_VERSION")
+ "/packages/"
+ (getenv "GUIX_ELM_PKG_NAME")
+ "/"
+ (getenv "GUIX_ELM_PKG_VERSION")))
+ (expected '("artifacts.dat" "docs.json")))
+ (for-each (lambda (name)
+ (search-input-file outputs (string-append base "/" name)))
+ expected)))
+
+(define %standard-phases
+ (modify-phases gnu:%standard-phases
+ (add-after 'unpack 'prepare-elm-home prepare-elm-home)
+ (delete 'bootstrap)
+ (add-after 'patch-source-shebangs 'stage stage)
+ (add-after 'stage 'make-offline-registry-file make-offline-registry-file)
+ (replace 'configure configure)
+ (delete 'patch-generated-file-shebangs)
+ (replace 'build build)
+ (replace 'check check)
+ (replace 'install install)
+ (add-before 'validate-documentation-location 'validate-compiled
+ validate-compiled)))
+
+(define* (elm-build #:key inputs (phases %standard-phases)
+ #:allow-other-keys #:rest args)
+ "Builds the given Elm project, applying all of the PHASES in order."
+ (apply gnu:gnu-build #:inputs inputs #:phases phases args))
diff --git a/tests/elm.scm b/tests/elm.scm
new file mode 100644
index 0000000000..96f958f060
--- /dev/null
+++ b/tests/elm.scm
@@ -0,0 +1,97 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022 Philip McGrath <philip@philipmcgrath.com>
+;;;
+;;; 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-elm)
+ #:use-module (guix build-system elm)
+ #:use-module (srfi srfi-64))
+
+(test-begin "elm")
+
+(test-group "elm->package-name and infer-elm-package-name"
+ (test-group "round trip"
+ ;; Cases when our heuristics can find the upstream name.
+ (define-syntax-rule (test-round-trip elm guix)
+ (test-group elm
+ (test-equal "elm->package-name" guix
+ (elm->package-name elm))
+ (test-equal "infer-elm-package-name" elm
+ (infer-elm-package-name guix))))
+ (test-round-trip "elm/core" "elm-core")
+ (test-round-trip "elm/html" "elm-html")
+ (test-round-trip "elm-explorations/markdown" "elm-explorations-markdown")
+ (test-round-trip "elm-explorations/test" "elm-explorations-test")
+ (test-round-trip "elm-explorations/foo-bar" "elm-explorations-foo-bar")
+ (test-round-trip "elm/explorations" "elm-explorations")
+ (test-round-trip "terezka/intervals" "elm-terezka-intervals")
+ (test-round-trip "justinmimbs/time-extra" "elm-justinmimbs-time-extra")
+ (test-round-trip "danhandrea/elm-date-format"
+ "elm-danhandrea-elm-date-format"))
+ (test-group "upstream-name needed"
+ ;; Upstream names that our heuristic can't infer. We still check that the
+ ;; round-trip behavior of 'infer-elm-package-name' works as promised for
+ ;; the hypothetical Elm name it doesn't infer.
+ (define-syntax-rule (test-upstream-needed elm guix inferred)
+ (test-group elm
+ (test-equal "elm->package-name" guix
+ (elm->package-name elm))
+ (test-group "infer-elm-package-name"
+ (test-equal "infers other name" inferred
+ (infer-elm-package-name guix))
+ (test-equal "infered name round-trips" guix
+ (elm->package-name inferred)))))
+ (test-upstream-needed "elm/virtual-dom"
+ "elm-virtual-dom"
+ "virtual/dom")
+ (test-upstream-needed "elm/project-metadata-utils"
+ "elm-project-metadata-utils"
+ "project/metadata-utils")
+ (test-upstream-needed "explorations/foo"
+ "elm-explorations-foo"
+ "elm-explorations/foo")
+ (test-upstream-needed "explorations/foo-bar"
+ "elm-explorations-foo-bar"
+ "elm-explorations/foo-bar")
+ (test-upstream-needed "explorations-central/foo"
+ "elm-explorations-central-foo"
+ "elm-explorations/central-foo")
+ (test-upstream-needed "explorations-central/foo-bar"
+ "elm-explorations-central-foo-bar"
+ "elm-explorations/central-foo-bar")
+ (test-upstream-needed "elm-xyz/foo"
+ "elm-xyz-foo"
+ "xyz/foo")
+ (test-upstream-needed "elm-xyz/foo-bar"
+ "elm-xyz-foo-bar"
+ "xyz/foo-bar")
+ (test-upstream-needed "elm-explorations-xyz/foo"
+ "elm-explorations-xyz-foo"
+ "elm-explorations/xyz-foo")
+ (test-upstream-needed "elm-explorations-xyz/foo-bar"
+ "elm-explorations-xyz-foo-bar"
+ "elm-explorations/xyz-foo-bar"))
+ (test-group "no inferred Elm name"
+ ;; Cases that 'infer-elm-package-name' should not attempt to handle,
+ ;; because 'elm->package-name' would never produce such names.
+ (define-syntax-rule (test-not-inferred guix)
+ (test-assert guix (not (infer-elm-package-name guix))))
+ (test-not-inferred "elm")
+ (test-not-inferred "guile")
+ (test-not-inferred "gcc-toolchain")
+ (test-not-inferred "font-adobe-source-sans-pro")))
+
+(test-end "elm")