Nix: package codemirror dependency

contrib/package/nix/deps/codemirror/default.nix

@@ -0,0 +1,32 @@
+{
+  lib,
+  buildNpmPackage,
+  fetchFromGitHub,
+}:
+
+buildNpmPackage rec {
+  pname = "codemirror";
+  version = "5.65.18";
+
+  src = fetchFromGitHub {
+    owner = "codemirror";
+    repo = "codemirror5";
+    tag = version;
+    hash = "sha256-VQTpLaTYfJRUKUjLgomE6TijHIZszQqH0L+khErruAU=";
+  };
+
+  env.PUPPETEER_SKIP_CHROMIUM_DOWNLOAD = true;
+
+  npmDepsHash = "sha256-OjftAKA4YQIHJqfZ0yuZbIWtgAJOLSeroLua3FA+rTk=";
+
+  patches = [
+    ./../../../../../scripts/deps-docker/codemirror.patch
+  ];
+
+  postPatch = ''
+    # Upstream doesn't have a package-lock.json
+    cp ${./package-lock.json} ./package-lock.json
+
+    sed -ri '/^var urlRE = /d' mode/gfm/gfm.js
+  '';
+}

contrib/package/nix/overlay.nix

@@ -3,6 +3,8 @@ final: prev: {
     ffmpeg = final.ffmpeg-full;
   };
 
+  codemirror = final.callPackage ./deps/codemirror { };
+
   python3 = prev.python3.override {
     packageOverrides = pyFinal: pyPrev: {
       partftpy = pyFinal.callPackage ./partftpy { };