hedgedoc: use fetchYarnDeps, add update script

pkgs/servers/web-apps/hedgedoc/default.nix

@@ -6,12 +6,15 @@
 , which
 , nodejs
 , mkYarnPackage
+, fetchYarnDeps
 , python2
 , nixosTests
 , buildGoModule
 }:
 
 let
+  pinData = (builtins.fromJSON (builtins.readFile ./pin.json));
+
   # we need a different version than the one already available in nixpkgs
   esbuild-hedgedoc = buildGoModule rec {
     pname = "esbuild";
@@ -30,19 +33,22 @@ in
 
 mkYarnPackage rec {
   pname = "hedgedoc";
-  version = "1.9.0";
+  inherit (pinData) version;
 
   src = fetchFromGitHub {
     owner  = "hedgedoc";
     repo   = "hedgedoc";
     rev    = version;
-    sha256 = "sha256-hSKQGkI1+68Zf05RhgRKZo47buyobzjhURSZ30/h0PA=";
+    sha256 = pinData.srcHash;
   };
 
   nativeBuildInputs = [ which makeWrapper ];
   extraBuildInputs = [ python2 esbuild-hedgedoc ];
 
-  yarnNix = ./yarn.nix;
+  offlineCache = fetchYarnDeps {
+    inherit yarnLock;
+    sha256 = pinData.yarnHash;
+  };
 
   # FIXME(@Ma27) on the bump to 1.9.0 I had to patch this file manually:
   # I replaced `midi "https://github.com/paulrosen/MIDI.js.git#abcjs"` with
@@ -101,7 +107,10 @@ mkYarnPackage rec {
     runHook postDist
   '';
 
-  passthru.tests = { inherit (nixosTests) hedgedoc; };
+  passthru = {
+    updateScript = ./update.sh;
+    tests = { inherit (nixosTests) hedgedoc; };
+  };
 
   meta = with lib; {
     description = "Realtime collaborative markdown notes on all platforms";

pkgs/servers/web-apps/hedgedoc/pin.json

@@ -0,0 +1,5 @@
+{
+  "version": "1.9.0",
+  "srcHash": "hSKQGkI1+68Zf05RhgRKZo47buyobzjhURSZ30/h0PA=",
+  "yarnHash": "0v51jmmbg8fx66ay2glby0gxw07in95igz325p42g5hjd5kankf6"
+}

pkgs/servers/web-apps/hedgedoc/update.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -I nixpkgs=../../../../ -i bash -p nix wget prefetch-yarn-deps nix-prefetch-github
+
+if [ "$#" -gt 1 ] || [[ "$1" == -* ]]; then
+  echo "Regenerates packaging data for the element packages."
+  echo "Usage: $0 [git release tag]"
+  exit 1
+fi
+
+version="$1"
+
+set -euo pipefail
+
+if [ -z "$version" ]; then
+  version="$(wget -O- "https://api.github.com/repos/hedgedoc/hedgedoc/releases?per_page=1" | jq -r '.[0].tag_name')"
+fi
+
+src="https://raw.githubusercontent.com/hedgedoc/hedgedoc/$version"
+wget "$src/package.json" -O package.json
+wget "$src/yarn.lock" -O yarn.lock
+sed 's;midi "https://github\.com/paulrosen/MIDI\.js\.git;midi "git+https://github.com/paulrosen/MIDI.js.git;g' -i yarn.lock
+
+src_hash=$(nix-prefetch-github hedgedoc hedgedoc --rev ${version} | jq -r .sha256)
+yarn_hash=$(prefetch-yarn-deps yarn.lock)
+
+cat > pin.json << EOF
+{
+  "version": "$version",
+  "srcHash": "$src_hash",
+  "yarnHash": "$yarn_hash"
+}
+EOF