Add nix output for web-grpc client bundled as JS

Author: palas

flake.nix

@@ -74,6 +74,8 @@
           };
         inherit (nixpkgs) lib;
 
+        proto-js-bundle-drv = import ./nix/proto-to-js.nix { pkgs = nixpkgs; };
+
         # We use cabalProject' to ensure we don't build the plan for
         # all systems.
         cabalProject = nixpkgs.haskell-nix.cabalProject' ({config, ...}: {
@@ -245,6 +247,9 @@
             # also provide hydraJobs through legacyPackages to allow building without system prefix:
             inherit hydraJobs;
           };
+          packages = lib.optionalAttrs (system != "aarch64-darwin") {
+            proto-js-bundle = proto-js-bundle-drv;
+          };
           devShells = let
             # profiling shell
             profilingShell = p: {

nix/npm-deps/package-lock.json

@@ -0,0 +1,6 @@
+{
+  "dependencies": {
+    "google-protobuf": "^3.21.4",
+    "grpc-web": "^1.5.0"
+  }
+}

nix/npm-deps/package.json

@@ -0,0 +1,88 @@
+# proto-to-js.nix
+
+{ pkgs ? import <nixpkgs> {} }:
+
+let
+
+  # Node dependencies
+  node-deps = pkgs.buildNpmPackage {
+    version = "1.0.0";
+    name = "proto-js-dependencies";
+    src = ../nix/npm-deps;
+    npmDepsHash = "sha256-b8x9xZ0dCu1cvILF0HPVVLfkCGHOWCcPUKyC2x1gQ+c=";
+    dontNpmBuild = true;
+    dontNpmInstall = true;
+    installPhase = ''
+      mkdir -p $out
+      cp -r node_modules $out/
+    '';
+  };
+
+  cardano-rpc-src = ../cardano-rpc;
+
+in pkgs.stdenv.mkDerivation {
+  pname = "cardano-rpc-proto-js-bundle";
+  version = "0.1.0";
+
+  src = cardano-rpc-src;
+
+  nativeBuildInputs = [
+    pkgs.protobuf
+    pkgs.protoc-gen-js
+    pkgs.protoc-gen-grpc-web
+    pkgs.nodePackages.browserify
+  ];
+
+  buildPhase = ''
+    runHook preBuild
+
+    PROTO_INCLUDE_PATH=$src/proto
+    GEN_JS_PATH=./generated-js
+    BUNDLE_PATH=./bundled-js
+
+    mkdir -p $GEN_JS_PATH
+    mkdir -p $BUNDLE_PATH
+
+    PROTO_FILE=$PROTO_INCLUDE_PATH/cardano/rpc/node.proto
+
+    echo "--- Compiling .proto file: $PROTO_FILE ---"
+
+    protoc \
+      -I=$PROTO_INCLUDE_PATH \
+      --js_out=import_style=commonjs,binary:$GEN_JS_PATH \
+      --grpc-web_out=import_style=commonjs,mode=grpcwebtext:$GEN_JS_PATH \
+      $PROTO_FILE
+
+    echo "--- Compilation finished. Generated files are in $GEN_JS_PATH ---"
+    ls -R $GEN_JS_PATH
+
+    GENERATED_GRPC_FILE=$GEN_JS_PATH/cardano/rpc/node_grpc_web_pb.js
+
+    if [ ! -f "$GENERATED_GRPC_FILE" ]; then
+        echo "Error: Protoc did not generate the expected gRPC-Web file!"
+        exit 1
+    fi
+
+    echo "--- Setting up node_modules for browserify ---"
+    ln -s ${node-deps}/node_modules ./node_modules
+
+    echo "--- Bundling generated JS with browserify ---"
+
+    browserify --standalone grpc $GENERATED_GRPC_FILE > $BUNDLE_PATH/node_grpc_web_pb.js
+
+    echo "--- Bundling complete. Final file is in $BUNDLE_PATH ---"
+    ls $BUNDLE_PATH
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out
+    cp ./bundled-js/node_grpc_web_pb.js $out/
+    runHook postInstall
+  '';
+
+  dontConfigure = true;
+}
+