feat(internal/rust): add toSidekickConfig (#2981)

Add functionality to convert a library from librarian.yaml to a
.sidekick.toml codec.

For #2966

Author: julieqiu

internal/sideflip/internal/rust/codec.go

@@ -0,0 +1,146 @@
+// Copyright 2025 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
+//
+//     http://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.
+
+package rust
+
+import (
+	"strings"
+
+	"github.com/googleapis/librarian/internal/sideflip/config"
+	sidekickconfig "github.com/googleapis/librarian/internal/sidekick/config"
+)
+
+func toSidekickConfig(library *config.Library, googleapisDir, serviceConfig string) *sidekickconfig.Config {
+	sidekickCfg := &sidekickconfig.Config{
+		General: sidekickconfig.GeneralConfig{
+			Language:            "rust",
+			SpecificationFormat: "protobuf",
+			ServiceConfig:       serviceConfig,
+			SpecificationSource: library.Channel,
+		},
+		Source: map[string]string{
+			"googleapis-root": googleapisDir,
+		},
+		Codec: buildCodec(library),
+	}
+
+	if library.Rust != nil {
+		if len(library.Rust.DocumentationOverrides) > 0 {
+			sidekickCfg.CommentOverrides = make([]sidekickconfig.DocumentationOverride, len(library.Rust.DocumentationOverrides))
+			for i, override := range library.Rust.DocumentationOverrides {
+				sidekickCfg.CommentOverrides[i] = sidekickconfig.DocumentationOverride{
+					ID:      override.ID,
+					Match:   override.Match,
+					Replace: override.Replace,
+				}
+			}
+		}
+
+		if len(library.Rust.PaginationOverrides) > 0 {
+			sidekickCfg.PaginationOverrides = make([]sidekickconfig.PaginationOverride, len(library.Rust.PaginationOverrides))
+			for i, override := range library.Rust.PaginationOverrides {
+				sidekickCfg.PaginationOverrides[i] = sidekickconfig.PaginationOverride{
+					ID:        override.ID,
+					ItemField: override.ItemField,
+				}
+			}
+		}
+	}
+	return sidekickCfg
+}
+
+func buildCodec(library *config.Library) map[string]string {
+	codec := make(map[string]string)
+	if library.Version != "" {
+		codec["version"] = library.Version
+	}
+	if library.ReleaseLevel != "" {
+		codec["release-level"] = library.ReleaseLevel
+	}
+	if library.Name != "" {
+		codec["package-name-override"] = library.Name
+	}
+	if library.CopyrightYear != "" {
+		codec["copyright-year"] = library.CopyrightYear
+	}
+	if library.Rust == nil {
+		return codec
+	}
+
+	rust := library.Rust
+	if rust.ModulePath != "" {
+		codec["module-path"] = rust.ModulePath
+	}
+	if library.Publish != nil && library.Publish.Disabled {
+		codec["not-for-publication"] = "true"
+	}
+	if len(rust.DisabledRustdocWarnings) > 0 {
+		codec["disabled-rustdoc-warnings"] = strings.Join(rust.DisabledRustdocWarnings, ",")
+	}
+	if len(rust.DisabledClippyWarnings) > 0 {
+		codec["disabled-clippy-warnings"] = strings.Join(rust.DisabledClippyWarnings, ",")
+	}
+	if rust.TemplateOverride != "" {
+		codec["template-override"] = rust.TemplateOverride
+	}
+	if rust.IncludeGrpcOnlyMethods {
+		codec["include-grpc-only-methods"] = "true"
+	}
+	if rust.PerServiceFeatures {
+		codec["per-service-features"] = "true"
+	}
+	if len(rust.DefaultFeatures) > 0 {
+		codec["default-features"] = strings.Join(rust.DefaultFeatures, ",")
+	}
+	if rust.DetailedTracingAttributes {
+		codec["detailed-tracing-attributes"] = "true"
+	}
+	if rust.HasVeneer {
+		codec["has-veneer"] = "true"
+	}
+	if len(rust.ExtraModules) > 0 {
+		codec["extra-modules"] = strings.Join(rust.ExtraModules, ",")
+	}
+	if rust.RoutingRequired {
+		codec["routing-required"] = "true"
+	}
+	if rust.GenerateSetterSamples {
+		codec["generate-setter-samples"] = "true"
+	}
+
+	for _, dep := range rust.PackageDependencies {
+		codec["package:"+dep.Name] = formatPackageDependency(dep)
+	}
+	return codec
+}
+
+func formatPackageDependency(dep config.RustPackageDependency) string {
+	var parts []string
+	if dep.Package != "" {
+		parts = append(parts, "package="+dep.Package)
+	}
+	if dep.Source != "" {
+		parts = append(parts, "source="+dep.Source)
+	}
+	if dep.ForceUsed {
+		parts = append(parts, "force-used=true")
+	}
+	if dep.UsedIf != "" {
+		parts = append(parts, "used-if="+dep.UsedIf)
+	}
+	if dep.Feature != "" {
+		parts = append(parts, "feature="+dep.Feature)
+	}
+	return strings.Join(parts, ",")
+}