scala_proto_library.md

scala_proto_library

To use this rule, you'll first need to add the following to your WORKSPACE file, which adds a few dependencies needed for ScalaPB:

scala_toolchains(
    # Other toolchains settings...
    scala_proto = True,
    scala_proto_options = [
        "grpc",
        "flat_package",
        "scala3_sources",
    ],
)

scala_register_toolchains()

Then you can import scala_proto_library in any BUILD file like this:

load("@rules_scala//scala_proto:scala_proto.bzl", "scala_proto_library")
scala_proto_library(
    name = "my_scala_proto_lib",
    deps = [":my_target"],
)

scala_proto_library generates a Scala library of Scala proto bindings generated by the ScalaPB compiler.

Attributes

Attribute name	Description
name	Name, required A unique name for this target.
deps	List of labels, required A list of proto_library targets for which to generate Scala code.

Configuration

If you want to have a different configuration from scala_proto_repositories, you can configure ScalaPB options and dependencies via toolchains.

To configure ScalaPB options, configure a different scala_proto_toolchain and declare it in a BUILD file:

load(
    "@rules_scala//scala_proto:scala_proto_toolchain.bzl",
    "scala_proto_toolchain",
)

scala_proto_toolchain(
    name = "scala_proto_toolchain",
    generators_opts = {
        "scala": [
            "grpc",
            "flat_package",
            "scala3_sources",
        ]
    },
    visibility = ["//visibility:public"],
)

toolchain(
    name = "scalapb_toolchain",
    toolchain = ":scala_proto_toolchain",
    toolchain_type = "@rules_scala//scala_proto:toolchain_type",
    visibility = ["//visibility:public"],
)

scala_proto_toolchain Toolchain Attributes

Attribute name	Description
name	Name, required A unique name for this toolchain.
generators_opts	List of strings, optional Additional protobuf options like 'grpc', 'flat_package' or 'scala3_sources'.
blacklisted_protos	List of labels, optional List of protobuf targets to exclude from recursive building.
code_generator	Label, optional (has default) Which code generator to use. A sensible default is provided.
generators	String dict, optional
extra_generator_dependencies	List of labels, optional
scalac	Label, optional (has default) Target for scalac. A sensible default is provided.

To configure dependencies, configure a different scala_proto_deps_toolchain and declare it in a BUILD file:

load("@rules_scala//scala:providers.bzl", "declare_deps_provider")
load(
    "@rules_scala//scala_proto:scala_proto_toolchain.bzl",
    "scala_proto_deps_toolchain",
)

scala_proto_deps_toolchain(
    name = "default_deps_toolchain_impl",
    visibility = ["//visibility:public"],
    dep_providers = [
        ":my_compile_deps",
    ],
)

toolchain(
    name = "default_deps_toolchain",
    toolchain = ":default_deps_toolchain_impl",
    toolchain_type = "@rules_scala//scala_proto:deps_toolchain_type",
)

declare_deps_provider(
    name = "my_compile_deps",
    deps_id = "scalapb_compile_deps",
    deps = ["@dep1", "@dep2"],
    visibility = ["//visibility:public"],
)

scala_proto_deps_toolchain Toolchain Attributes

Attribute name	Description
dep_providers	List of labels, optional (has default) allows injection of gRPC (deps_id - scalapb_worker_deps) and ScalaPB (deps_id scalapb_compile_deps) dependencies