@aspect_rules_js//js:proto.bzl

Documentation for @aspect_rules_js@v3.0.3 — View source

EXPERIMENTAL: Protobuf and gRPC support for JavaScript and TypeScript. This API is subject to breaking changes outside our usual semver policy. In a future release of rules_js this should become stable.

Typical setup

Choose any code generator plugin for protoc. In this example we’ll show @bufbuild/protoc-gen-es that produces both message marshaling and service stubs for JavaScript and TypeScript. It should be added as a devDependency in your package.json, typically under a /tools directory. The generator is expected to produce .js and .d.ts files for each .proto file.
Declare a binary target that runs the generator, typically using its package_json.bzl entry point, for example in tools/toolchains/BUILD:

load("@npm//tools:@bufbuild/protoc-gen-es/package_json.bzl", gen_es = "bin")
gen_es.protoc_gen_es_binary(name = "protoc_gen_es")

Define a js_proto_toolchain that uses the plugin. See the rule documentation below.
Update MODULE.bazel to register it, typically with a simple statement like register_toolchains("//tools/toolchains:all")

Usage

Just write proto_library targets as usual, or have Gazelle generate them. Then reference them anywhere a js_library could appear, for example:

load("@aspect_rules_js//js:defs.bzl", "js_library")
load("@protobuf//bazel:proto_library.bzl", "proto_library")

proto_library(
    name = "eliza_proto",
    srcs = ["eliza.proto"],
)

js_library(
    name = "proto",
    srcs = ["package.json"],
    deps = [":eliza_proto"],
)

The generator you setup earlier will be invoked automatically as an action to generate the .js and .d.ts files.

Function: `js_proto_toolchain`

Define a proto_lang_toolchain that uses the plugin. Example:

js_proto_toolchain(
    name = "gen_es_toolchain",
    plugin_bin = ":protoc_gen_es",
    plugin_name = "es",
    # See https://github.com/bufbuild/protobuf-es/tree/main/packages/protoc-gen-es#plugin-options
    plugin_options = [
        "keep_empty_files=true",
        "target=js+dts",
        "import_extension=js",
    ],
    runtime = "//:node_modules/@bufbuild/protobuf",
)

Parameters

unknown

required

The name of the toolchain. A target named [name]_toolchain is also created, which is the one to be used in register_toolchains.

unknown

required

The NAME of the plugin program, used in command-line flags to protoc, as follows:

protoc --plugin=protoc-gen-NAME=path/to/mybinary --NAME_out=OUT_DIR

See https://protobuf.dev/reference/cpp/api-docs/google.protobuf.compiler.plugin

unknown

required

(List of strings) Command line flags used to invoke the plugin, based on documentation for the generator.For example, for @bufbuild/protoc-gen-es, reference the documentation at https://github.com/bufbuild/protobuf-es/tree/main/packages/protoc-gen-es#plugin-options to arrive at a value like ["import_extension=js"]

unknown

required

The plugin to use. This should be the label of a binary target that you declared in step 2 above.

unknown

required

The runtime to use, which is imported by the generated code. For example, ”//:node_modules/@bufbuild/protobuf”.Note that node module resolution requires the runtime to be in a parent folder of any package containing generated code.

unknown

Additional arguments to pass to the proto_lang_toolchain rule.

​Typical setup

​Usage

​Function: js_proto_toolchain

​Parameters

Typical setup

Usage

Function: `js_proto_toolchain`

Parameters