chore(tool/cmd/migrate): parse extra dependencies for ruby migration (#6921)

Update the Ruby migration tool to extract the
`ruby-cloud-extra-dependencies` parameter from `BUILD.bazel` rules in
googleapis and set the `extra_dependencies` configuration for Ruby APIs.

This adds the `extra_dependencies` field to RubyAPI in internal/config
and updates the config schema documentation.

For #6632

Author: JoeWang1127

doc/config-schema.md

@@ -488,6 +488,7 @@ This document describes the schema for the librarian.yaml.
 | Field | Type | Description |
 | :--- | :--- | :--- |
 | `env_prefix` | string | Is the environment variable prefix. |
+| `extra_dependencies` | string | Contains extra runtime dependencies to the .gemspec file. |
 
 ## RubyPackage Configuration
 

internal/config/language.go

@@ -851,4 +851,7 @@ type RubyPackage struct {
 type RubyAPI struct {
 	// EnvPrefix is the environment variable prefix.
 	EnvPrefix string `yaml:"env_prefix,omitempty"`
+
+	// ExtraDependencies contains extra runtime dependencies to the .gemspec file.
+	ExtraDependencies string `yaml:"extra_dependencies,omitempty"`
 }

tool/cmd/migrate/ruby.go

@@ -24,7 +24,6 @@ import (
 	"path/filepath"
 	"regexp"
 	"slices"
-	"sort"
 	"strings"
 
 	"github.com/googleapis/librarian/internal/config"
@@ -49,6 +48,7 @@ type owlbotSrc struct {
 // VersionedBuild represents build configuration parsed from BUILD.bazel for a Ruby API version.
 type VersionedBuild struct {
 	EnvPrefix string
+	ExtraDeps string
 }
 
 func runRubyMigration(ctx context.Context, repoPath string) error {
@@ -133,7 +133,8 @@ func findRubyLibraries(googleapisPath, repoPath string) ([]*config.Library, erro
 			}
 			if vb != nil {
 				lib.APIs[0].Ruby = &config.RubyAPI{
-					EnvPrefix: vb.EnvPrefix,
+					EnvPrefix:         vb.EnvPrefix,
+					ExtraDependencies: vb.ExtraDeps,
 				}
 			}
 		}
@@ -169,8 +170,8 @@ func parseAPIFromOwlBot(owlBotPath string) (string, error) {
 
 // parseWrapperOf sets the WrapperOf field for wrapper libraries.
 func parseWrapperOf(libraries []*config.Library) {
-	sort.Slice(libraries, func(i, j int) bool {
-		return libraries[i].Name < libraries[j].Name
+	slices.SortFunc(libraries, func(a, b *config.Library) int {
+		return strings.Compare(a.Name, b.Name)
 	})
 	for i, lib := range libraries {
 		if len(lib.APIs) != 0 {
@@ -215,6 +216,8 @@ func parseVersionedBuild(googleapisDir, apiPath string) (*VersionedBuild, error)
 				switch {
 				case strings.HasPrefix(dep, "ruby-cloud-env-prefix="):
 					vb.EnvPrefix, _ = strings.CutPrefix(dep, "ruby-cloud-env-prefix=")
+				case strings.HasPrefix(dep, "ruby-cloud-extra-dependencies="):
+					vb.ExtraDeps, _ = strings.CutPrefix(dep, "ruby-cloud-extra-dependencies=")
 				}
 			}
 		}

tool/cmd/migrate/ruby_test.go

@@ -90,6 +90,18 @@ func TestFindRubyLibraries(t *testing.T) {
 		t.Fatal(err)
 	}
 	want := []*config.Library{
+		{
+			Name: "google-cloud-compute-v1",
+			APIs: []*config.API{
+				{
+					Path: "google/cloud/compute/v1",
+					Ruby: &config.RubyAPI{
+						EnvPrefix:         "COMPUTE",
+						ExtraDependencies: "google-cloud-common=~> 1.0",
+					},
+				},
+			},
+		},
 		{
 			Name: "google-cloud-secret_manager",
 			Ruby: &config.RubyPackage{

tool/cmd/migrate/testdata/google-cloud-ruby/google-cloud-compute-v1/.OwlBot.yaml

@@ -0,0 +1,16 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+deep-copy-regex:
+  - source: /google/cloud/compute/v1/[^/]+-ruby/(.*)
+    dest: /owl-bot-staging/google-cloud-compute-v1/$1

tool/cmd/migrate/testdata/googleapis/google/cloud/compute/v1/BUILD.bazel

@@ -60,4 +60,49 @@ go_gapic_assembly_pkg(
         ":compute_go_gapic_srcjar-test.srcjar",
         ":compute_go_proto",
     ],
+)
+
+###############################################################################
+# Ruby
+###############################################################################
+load(
+    "@com_google_googleapis_imports//:imports.bzl",
+    "ruby_cloud_gapic_library",
+    "ruby_gapic_assembly_pkg",
+    "ruby_proto_library",
+)
+
+ruby_proto_library(
+    name = "compute_ruby_proto",
+    deps = [":compute_proto"],
+)
+
+ruby_cloud_gapic_library(
+    name = "compute_ruby_gapic",
+    srcs = [":compute_proto_with_info"],
+    extra_protoc_parameters = [
+        "ruby-cloud-api-id=compute.googleapis.com",
+        "ruby-cloud-api-shortname=compute",
+        "ruby-cloud-gem-name=google-cloud-compute-v1",
+        "ruby-cloud-generate-metadata=false",
+        "ruby-cloud-generate-transports=rest",
+        "ruby-cloud-env-prefix=COMPUTE",
+        "ruby-cloud-product-url=https://cloud.google.com/compute/",
+        "ruby-cloud-wrapper-gem-override=",
+        "ruby-cloud-extra-dependencies=google-cloud-common=~> 1.0",
+    ],
+    grpc_service_config = ":compute_grpc_service_config.json",
+    ruby_cloud_description = "google-cloud-compute-v1 is the official client library for the Google Cloud Compute V1 API.",
+    ruby_cloud_title = "Google Cloud Compute V1",
+    deps = [
+        ":compute_ruby_proto",
+    ],
+)
+
+ruby_gapic_assembly_pkg(
+    name = "google-cloud-compute-v1-ruby",
+    deps = [
+        ":compute_ruby_gapic",
+        ":compute_ruby_proto",
+    ],
 )