add output paths to each of the js language modules

examples/js-es-custom-outputpath/README.md

@@ -0,0 +1,57 @@
+# JavaScript ES Modules with Custom Output Path
+
+This example demonstrates using a custom `outputPath` specifically for the ES modules plugin.
+
+## Overview
+
+This example shows how to configure JavaScript/TypeScript code generation with a plugin-specific output path, which is useful in monorepo scenarios where different code generation plugins need to output to different locations.
+
+## Configuration
+
+```nix
+languages.js = {
+  enable = true;
+  es = {
+    enable = true;
+    outputPath = "proto/gen/js";  # Custom path for ES modules
+    options = [
+      "target=ts"
+      "import_extension=.js"
+      "json_types=true"
+    ];
+  };
+};
+```
+
+## Key Features
+
+- **Plugin-specific output paths**: Set different output directories for different plugins
+- **TypeScript target**: Generates `.ts` files with type definitions
+- **ES modules**: Modern JavaScript with import/export syntax
+- **JSON types**: Includes JSON type definitions for serialization
+
+## Usage
+
+```bash
+# Generate TypeScript code
+nix run
+
+# View generated files
+ls proto/gen/js/example/v1/
+```
+
+## Generated Files
+
+- `proto/gen/js/example/v1/example_pb.ts` - Generated TypeScript protobuf messages
+
+## Use Cases
+
+This pattern is especially useful when:
+- Working with monorepos where frontend and backend have different structure requirements
+- Using multiple JS plugins (ES, gRPC-Web, Twirp) that need separate output locations
+- Integrating with existing project structures that have specific directory conventions
+
+## See Also
+
+- [js-example](../js-example/) - Basic JavaScript example with default paths
+- [js-grpc-web](../js-grpc-web/) - gRPC-Web example

examples/js-es-custom-outputpath/flake.nix

@@ -0,0 +1,56 @@
+{
+  description = "JavaScript ES modules example with custom outputPath - tests plugin-specific output paths";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    # bufrnix.url = "github:conneroisu/bufrnix";
+    bufrnix.url = "path:../..";
+    bufrnix.inputs.nixpkgs.follows = "nixpkgs";
+  };
+
+  outputs = {
+    nixpkgs,
+    flake-utils,
+    bufrnix,
+    ...
+  }:
+    flake-utils.lib.eachDefaultSystem (system: let
+      pkgs = nixpkgs.legacyPackages.${system};
+    in {
+      devShells.default = pkgs.mkShell {
+        packages = [
+          pkgs.nodejs
+          pkgs.nodePackages.typescript
+        ];
+      };
+      packages = {
+        default = bufrnix.lib.mkBufrnixPackage {
+          inherit pkgs;
+
+          config = {
+            root = ./.;
+            protoc = {
+              sourceDirectories = ["./proto"];
+              includeDirectories = ["./proto"];
+              files = ["./proto/example/v1/example.proto"];
+            };
+            languages.js = {
+              enable = true;
+              # This demonstrates the bug: setting outputPath at ES plugin level
+              # Currently this gets ignored and uses the default "gen/js" instead
+              es = {
+                enable = true;
+                outputPath = "proto/gen/js";  # Custom path for ES modules
+                options = [
+                  "target=ts"
+                  "import_extension=.js"
+                  "json_types=true"
+                ];
+              };
+            };
+          };
+        };
+      };
+    });
+}

examples/js-es-custom-outputpath/proto/example/v1/example.proto

@@ -0,0 +1,23 @@
+syntax = "proto3";
+
+package example.v1;
+
+// Simple message for testing custom outputPath
+message User {
+  string id = 1;
+  string name = 2;
+  string email = 3;
+}
+
+// Simple service for testing
+service UserService {
+  rpc GetUser(GetUserRequest) returns (GetUserResponse);
+}
+
+message GetUserRequest {
+  string user_id = 1;
+}
+
+message GetUserResponse {
+  User user = 1;
+}

src/languages/js/default.nix

@@ -11,12 +11,13 @@ with lib; let
   jsOptions = cfg.options;
 
   # Import JS-specific sub-modules
+  # Use plugin-specific outputPath if set, otherwise fall back to parent outputPath
   grpcWebModule = import ./grpc-web.nix {
     inherit pkgs lib;
     cfg =
       cfg.grpcWeb
       // {
-        outputPath = outputPath;
+        outputPath = if (cfg.grpcWeb.outputPath or null) != null then cfg.grpcWeb.outputPath else outputPath;
       };
   };
 
@@ -25,7 +26,7 @@ with lib; let
     cfg =
       cfg.twirp
       // {
-        outputPath = outputPath;
+        outputPath = if (cfg.twirp.outputPath or null) != null then cfg.twirp.outputPath else outputPath;
       };
   };
 
@@ -47,7 +48,7 @@ with lib; let
     cfg =
       cfg.tsProto
       // {
-        outputPath = outputPath;
+        outputPath = if (cfg.tsProto.outputPath or null) != null then cfg.tsProto.outputPath else outputPath;
       };
   };
 
@@ -78,27 +79,33 @@ in {
     (optional (cfg.package != null)
       "--js_out=import_style=commonjs,binary:${outputPath}")
     ++ (optionals cfg.es.enable (let
+      esOutputPath = if (cfg.es.outputPath != null) then cfg.es.outputPath else outputPath;
       esOptions =
         cfg.es.options
         ++ (optional (cfg.es.target != "") "target=${cfg.es.target}")
         ++ (optional (cfg.es.importExtension != "") "import_extension=${cfg.es.importExtension}");
     in [
       "--plugin=protoc-gen-es=${cfg.es.package}/bin/protoc-gen-es"
-      "--es_out=${outputPath}"
+      "--es_out=${esOutputPath}"
       (optionalString (esOptions != []) "--es_opt=${concatStringsSep "," esOptions}")
     ]))
     ++ (optionals cfg.tsProto.enable (tsProtoModule.protocPlugins or []))
     ++ (combineModuleAttrs "protocPlugins");
 
   # Initialization hook for JS
   initHooks =
-    ''
+    (let
+      esOutputPath = if (cfg.es.outputPath != null) then cfg.es.outputPath else outputPath;
+    in ''
       # Create js-specific directories
       mkdir -p "${outputPath}"
+      ${optionalString cfg.es.enable ''
+        mkdir -p "${esOutputPath}"
+      ''}
       ${optionalString (cfg.packageName != "") ''
         echo "Creating JS package: ${cfg.packageName}"
       ''}
-    ''
+    '')
     + concatStrings (catAttrs "initHooks" [
       grpcWebModule
       twirpModule
@@ -117,8 +124,10 @@ in {
       ''}
 
       # Generate package.json for ES modules if requested
-      ${optionalString (cfg.es.enable && cfg.es.generatePackageJson) ''
-                cat > ${outputPath}/package.json <<EOF
+      ${optionalString (cfg.es.enable && cfg.es.generatePackageJson) (let
+        esOutputPath = if (cfg.es.outputPath != null) then cfg.es.outputPath else outputPath;
+      in ''
+                cat > ${esOutputPath}/package.json <<EOF
         {
           "name": "${
           if cfg.es.packageName != ""
@@ -148,7 +157,7 @@ in {
         }
         EOF
                 echo "Generated package.json for ES modules"
-      ''}
+      '')}
     ''
     + concatStrings (catAttrs "generateHooks" [
       grpcWebModule