From aff01371c15af5bc2abffcb9851a550cdbe58dbb Mon Sep 17 00:00:00 2001
From: "(cdep)illabout" <cdep.illabout@gmail.com>
Date: Thu, 26 Aug 2021 10:20:27 +0900
Subject: [PATCH] purescript: add updateScript for automatic updates

---
 .../purescript/purescript/default.nix         |  8 +++-
 .../compilers/purescript/purescript/update.sh | 43 +++++++++++++++++++
 2 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100755 pkgs/development/compilers/purescript/purescript/update.sh

diff --git a/pkgs/development/compilers/purescript/purescript/default.nix b/pkgs/development/compilers/purescript/purescript/default.nix
index 2d444578db54..9b71975f5023 100644
--- a/pkgs/development/compilers/purescript/purescript/default.nix
+++ b/pkgs/development/compilers/purescript/purescript/default.nix
@@ -20,6 +20,7 @@ in stdenv.mkDerivation rec {
   pname = "purescript";
   version = "0.14.4";
 
+  # These hashes can be updated automatically by running the ./update.sh script.
   src =
     if stdenv.isDarwin
     then
@@ -51,8 +52,11 @@ in stdenv.mkDerivation rec {
     $PURS --bash-completion-script $PURS > $out/share/bash-completion/completions/purs-completion.bash
   '';
 
-  passthru.tests = {
-    minimal-module = pkgs.callPackage ./test-minimal-module {};
+  passthru = {
+    updateScript = ./update.sh;
+    tests = {
+      minimal-module = pkgs.callPackage ./test-minimal-module {};
+    };
   };
 
   meta = with lib; {
diff --git a/pkgs/development/compilers/purescript/purescript/update.sh b/pkgs/development/compilers/purescript/purescript/update.sh
new file mode 100755
index 000000000000..de8787ba4cca
--- /dev/null
+++ b/pkgs/development/compilers/purescript/purescript/update.sh
@@ -0,0 +1,43 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p curl jq -I nixpkgs=.
+#
+# This script will update the purescript derivation to the latest version.
+
+set -eo pipefail
+
+# This is the directory of this update.sh script.
+script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+
+purescript_derivation_file="${script_dir}/default.nix"
+
+# This is the current revision of PureScript in Nixpkgs.
+old_version="$(sed -En 's/.*\bversion = "(.*?)".*/\1/p' "$purescript_derivation_file")"
+
+# This is the latest release version of PureScript on GitHub.
+new_version=$(curl --silent "https://api.github.com/repos/purescript/purescript/releases" | jq '.[0].tag_name' --raw-output | sed -e 's/v//')
+
+echo "Updating purescript from old version v${old_version} to new version v${new_version}."
+echo
+
+echo "Fetching both old and new release tarballs for Darwin and Linux in order to confirm hashes."
+echo
+old_linux_version_hash="$(nix-prefetch-url "https://github.com/purescript/purescript/releases/download/v${old_version}/linux64.tar.gz")"
+echo "v${old_version} linux tarball hash (current version): $old_linux_version_hash"
+new_linux_version_hash="$(nix-prefetch-url "https://github.com/purescript/purescript/releases/download/v${new_version}/linux64.tar.gz")"
+echo "v${new_version} linux tarball hash: $new_linux_version_hash"
+old_darwin_version_hash="$(nix-prefetch-url "https://github.com/purescript/purescript/releases/download/v${old_version}/macos.tar.gz")"
+echo "v${old_version} darwin tarball hash (current version): $old_darwin_version_hash"
+new_darwin_version_hash="$(nix-prefetch-url "https://github.com/purescript/purescript/releases/download/v${new_version}/macos.tar.gz")"
+echo "v${new_version} darwin tarball hash: $new_darwin_version_hash"
+echo
+
+echo "Replacing version and hashes in ${purescript_derivation_file}."
+sed -i -e "s/${old_linux_version_hash}/${new_linux_version_hash}/" "$purescript_derivation_file"
+sed -i -e "s/${old_darwin_version_hash}/${new_darwin_version_hash}/" "$purescript_derivation_file"
+sed -i -e "s/${old_version}/${new_version}/" "$purescript_derivation_file"
+echo
+
+echo "Finished.  Make sure you run the following commands to confirm PureScript builds correctly:"
+echo ' - `nix build -L -f ./. purescript`'
+echo ' - `nix build -L -f ./. purescript.passthru.tests.minimal-module`'
+echo ' - `sudo nix build -L -f ./. spago.passthru.tests --option sandbox relaxed`'