feat: support incompatible_enable_proto_toolchain_resolution (#608)

* feat: support incompatible_enable_proto_toolchain_resolution

See bazelbuild/rules_proto#213

* Also upgrade rules_proto for WORKSPACE tests

* fix: install bazel_features explicitly

This seems like a bug in rules_proto that the initializer call can't bootstrap because it hits a bazel_features load

MODULE.bazel

@@ -12,13 +12,12 @@ bazel_dep(name = "aspect_rules_js", version = "1.34.0")
 bazel_dep(name = "bazel_skylib", version = "1.4.1")
 bazel_dep(name = "platforms", version = "0.0.5")
 
-# Only needed because rules_proto doesn't provide the protoc toolchain yet.
-# TODO(alex/sahin): remove in the future
+# TODO(4.x): remove support for non-toolchainized protoc
 bazel_dep(name = "protobuf", version = "21.7", repo_name = "com_google_protobuf")
 
 # Similar to rules_python/MODULE.bazel, see https://github.com/bazelbuild/rules_python/pull/832
 # These are loaded only when using ts_proto_library
-bazel_dep(name = "rules_proto", version = "5.3.0-21.7")
+bazel_dep(name = "rules_proto", version = "6.0.0")
 
 ####### Dev dependencies ########
 

WORKSPACE

@@ -102,6 +102,10 @@ npm_repositories()
 # bazel run -- @npm_typescript//:tsc --version
 rules_ts_dependencies(ts_version_from = "@npm//examples:typescript/resolved.json")
 
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+
+bazel_features_deps()
+
 ###########################################
 # Protobuf rules to test ts_proto_library
 load("@rules_proto//proto:repositories.bzl", "rules_proto_dependencies")

e2e/bzlmod/.bazelrc

@@ -9,6 +9,8 @@ import %workspace%/../../.aspect/bazelrc/performance.bazelrc
 ### YOUR PROJECT SPECIFIC OPTIONS GO HERE ###
 
 common --@aspect_rules_ts//ts:skipLibCheck=honor_tsconfig
+# NB: comment this line out to test the legacy path to @com_google_protobuf//:protoc
+common --incompatible_enable_proto_toolchain_resolution
 
 # Load any settings & overrides specific to the current user from `.aspect/bazelrc/user.bazelrc`.
 # This file should appear in `.gitignore` so that settings are not shared with team members. This

e2e/bzlmod/MODULE.bazel

@@ -8,6 +8,7 @@ local_path_override(
 bazel_dep(name = "aspect_rules_js", version = "1.34.0", dev_dependency = True)
 bazel_dep(name = "bazel_skylib", version = "1.4.1", dev_dependency = True)
 bazel_dep(name = "rules_proto", version = "5.3.0-21.7", dev_dependency = True)
+bazel_dep(name = "toolchains_protoc", version = "0.2.4", dev_dependency = True)
 
 npm = use_extension("@aspect_rules_js//npm:extensions.bzl", "npm", dev_dependency = True)
 npm.npm_translate_lock(

internal_deps.bzl

@@ -37,13 +37,18 @@ def rules_ts_internal_deps():
         urls = ["https://github.com/bazelbuild/stardoc/releases/download/0.6.2/stardoc-0.6.2.tar.gz"],
     )
 
+    http_archive(
+        name = "bazel_features",
+        sha256 = "2cd9e57d4c38675d321731d65c15258f3a66438ad531ae09cb8bb14217dc8572",
+        strip_prefix = "bazel_features-1.11.0",
+        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.11.0/bazel_features-v1.11.0.tar.gz",
+    )
+
     http_archive(
         name = "rules_proto",
-        sha256 = "dc3fb206a2cb3441b485eb1e423165b231235a1ea9b031b4433cf7bc1fa460dd",
-        strip_prefix = "rules_proto-5.3.0-21.7",
-        urls = [
-            "https://github.com/bazelbuild/rules_proto/archive/refs/tags/5.3.0-21.7.tar.gz",
-        ],
+        sha256 = "303e86e722a520f6f326a50b41cfc16b98fe6d1955ce46642a5b7a67c11c0f5d",
+        strip_prefix = "rules_proto-6.0.0",
+        url = "https://github.com/bazelbuild/rules_proto/releases/download/6.0.0/rules_proto-6.0.0.tar.gz",
     )
 
     http_archive(

ts/private/ts_proto_library.bzl

@@ -4,6 +4,9 @@ load("@aspect_bazel_lib//lib:copy_to_bin.bzl", "COPY_FILE_TO_BIN_TOOLCHAINS")
 load("@aspect_rules_js//js:libs.bzl", "js_lib_helpers")
 load("@aspect_rules_js//js:providers.bzl", "JsInfo", "js_info")
 load("@rules_proto//proto:defs.bzl", "ProtoInfo", "proto_common")
+load("@rules_proto//proto:proto_common.bzl", proto_toolchains = "toolchains")
+
+_PROTO_TOOLCHAIN_TYPE = "@rules_proto//proto:toolchain_type"
 
 # buildifier: disable=function-docstring-header
 def _protoc_action(ctx, proto_info, outputs, options = {
@@ -43,8 +46,9 @@ def _protoc_action(ctx, proto_info, outputs, options = {
 
     args.add_all(proto_info.direct_sources)
 
+    proto_toolchain_enabled = len(proto_toolchains.use_toolchain(_PROTO_TOOLCHAIN_TYPE)) > 0
     ctx.actions.run(
-        executable = ctx.executable.protoc,
+        executable = ctx.toolchains[_PROTO_TOOLCHAIN_TYPE].proto.proto_compiler if proto_toolchain_enabled else ctx.executable.protoc,
         progress_message = "Generating .js/.d.ts from %{label}",
         outputs = outputs,
         inputs = inputs,
@@ -107,7 +111,7 @@ def _ts_proto_library_impl(ctx):
 
 ts_proto_library = rule(
     implementation = _ts_proto_library_impl,
-    attrs = {
+    attrs = dict({
         "deps": attr.label_list(
             providers = [JsInfo],
             doc = "Other ts_proto_library rules. TODO: could we collect them with an aspect",
@@ -129,7 +133,6 @@ ts_proto_library = rule(
             providers = [ProtoInfo],
             mandatory = True,
         ),
-        "protoc": attr.label(default = "@com_google_protobuf//:protoc", executable = True, cfg = "exec"),
         "protoc_gen_es": attr.label(
             doc = "protoc plugin to generate messages",
             mandatory = True,
@@ -146,6 +149,8 @@ ts_proto_library = rule(
             executable = True,
             cfg = "exec",
         ),
-    },
-    toolchains = COPY_FILE_TO_BIN_TOOLCHAINS,
+    }, **proto_toolchains.if_legacy_toolchain({
+        "protoc": attr.label(default = "@com_google_protobuf//:protoc", executable = True, cfg = "exec"),
+    })),
+    toolchains = COPY_FILE_TO_BIN_TOOLCHAINS + proto_toolchains.use_toolchain(_PROTO_TOOLCHAIN_TYPE),
 )