Add support for Protobuf Editions (#284)

This PR adds support for Protobuf Editions to Connect-Swift plugins.
There is no change to generated outputs in this PR, but it adds
`supportsEditions` and `supportedEditionRange` specifications in the
`Generator` class to ensure the Connect plugins can run with Protobuf
files that use Editions.

SwiftProtobuf also deprecated some usages of
`Google_Protobuf_Compiler_CodeGeneratorResponse`:

>
'Google_Protobuf_Compiler_CodeGeneratorResponse.init(files:supportedFeatures:)'
is deprecated: Please move your plugin to the CodeGenerator interface

As part of these changes, I migrated over to using `CodeGenerator` in
order to be able to specify the new Editions-related variables mentioned
above.

---------

Signed-off-by: Michael Rebello <[email protected]>

Package.swift

@@ -145,6 +145,7 @@ let package = Package(
  .target(
  name: "ConnectPluginUtilities",
  dependencies: [
+ .product(name: "SwiftProtobuf", package: "swift-protobuf"),
  .product(name: "SwiftProtobufPluginLibrary", package: "swift-protobuf"),
  ],
  path: "Plugins/ConnectPluginUtilities"

Plugins/ConnectMocksPlugin/ConnectMockGenerator.swift

@@ -16,34 +16,35 @@ import ConnectPluginUtilities
 import Foundation
 import SwiftProtobufPluginLibrary
 
-/// Responsible for generating services and RPCs that are compatible with the Connect library.
+/// Responsible for generating mocks that are compatible with generated Connect services.
+@main
 final class ConnectMockGenerator: Generator {
- private let propertyVisibility: String
- private let typeVisibility: String
+ private var propertyVisibility = ""
+ private var typeVisibility = ""
 
- required init(_ descriptor: FileDescriptor, options: GeneratorOptions) {
- switch options.visibility {
+ override var outputFileExtension: String {
+ return ".mock.swift"
+ }
+
+ override func printContent(for descriptor: FileDescriptor) {
+ super.printContent(for: descriptor)
+
+ switch self.options.visibility {
  case .internal:
  self.propertyVisibility = "internal"
  self.typeVisibility = "internal"
  case .public:
  self.propertyVisibility = "public"
  self.typeVisibility = "open"
  }
- super.init(descriptor, options: options)
- self.printContent()
- }
-
- private func printContent() {
- self.printFilePreamble()
 
  if self.options.generateCallbackMethods {
  self.printModuleImports(adding: ["Combine", "ConnectMocks"])
  } else {
  self.printModuleImports(adding: ["ConnectMocks"])
  }
 
- for service in self.descriptor.services {
+ for service in self.services {
  self.printLine()
  self.printMockService(service)
  }

Plugins/ConnectPluginUtilities/Generator.swift

@@ -12,31 +12,53 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+import SwiftProtobuf
 import SwiftProtobufPluginLibrary
 
-/// Base generator class that can be used to output a file from a Protobuf file descriptor.
+private struct GeneratorError: Swift.Error {
+ let message: String
+}
+
+/// Base generator class that can be used to generate Swift files from Protobuf file descriptors.
+/// Not intended to be instantiated directly.
+/// Subclasses must be annotated with `@main` to be properly invoked at runtime.
 open class Generator {
- private var printer = CodePrinter(indent: " ".unicodeScalars)
+ private var neededModules = [String]()
+ private var printer = SwiftProtobufPluginLibrary.CodePrinter()
 
- public let descriptor: FileDescriptor
- public let namer: SwiftProtobufNamer
- public let options: GeneratorOptions
+ // MARK: - Overridable
 
- public var output: String {
- return self.printer.content
+ /// File extension to use for generated file names (e.g., ".connect.swift").
+ /// Must be overridden by subclasses.
+ open var outputFileExtension: String {
+ fatalError("\(#function) must be overridden by subclasses")
  }
 
- public required init(_ descriptor: FileDescriptor, options: GeneratorOptions) {
- self.descriptor = descriptor
- self.options = options
- self.namer = SwiftProtobufNamer(
- currentFile: descriptor,
- protoFileToModuleMappings: options.protoToModuleMappings
- )
+ /// Initializer required by `SwiftProtobufPluginLibrary.CodeGenerator`.
+ public required init() {}
+
+ /// Should be overridden by subclasses to write output for a given file descriptor.
+ /// Subclasses should call `super` before producing their own outputs.
+ /// May be called multiple times (once per file descriptor) over the lifetime of this class.
+ ///
+ /// - parameter descriptor: The file descriptor for which to generate code.
+ open func printContent(for descriptor: SwiftProtobufPluginLibrary.FileDescriptor) {
+ self.printLine("// Code generated by protoc-gen-connect-swift. DO NOT EDIT.")
+ self.printLine("//")
+ self.printLine("// Source: \(descriptor.name)")
+ self.printLine("//")
+ self.printLine()
  }
 
  // MARK: - Output helpers
 
+ /// Used for producing type names when generating code.
+ public private(set) var namer = SwiftProtobufPluginLibrary.SwiftProtobufNamer()
+ /// Options to use when generating code.
+ public private(set) var options = GeneratorOptions.empty()
+ /// List of services specified in the current file.
+ public private(set) var services = [SwiftProtobufPluginLibrary.ServiceDescriptor]()
+
  public func indent() {
  self.printer.indent()
  }
@@ -58,30 +80,81 @@ open class Generator {
  self.printer.print("\n")
  }
 
- public func printCommentsIfNeeded(for entity: ProvidesSourceCodeLocation) {
+ public func printCommentsIfNeeded(
+ for entity: SwiftProtobufPluginLibrary.ProvidesSourceCodeLocation
+ ) {
  let comments = entity.protoSourceComments().trimmingCharacters(in: .whitespacesAndNewlines)
  if !comments.isEmpty {
  self.printLine(comments)
  }
  }
 
- public func printFilePreamble() {
- self.printLine("// Code generated by protoc-gen-connect-swift. DO NOT EDIT.")
- self.printLine("//")
- self.printLine("// Source: \(self.descriptor.name)")
- self.printLine("//")
- self.printLine()
- }
-
  public func printModuleImports(adding additional: [String] = []) {
  let defaults = ["Connect", "Foundation", self.options.swiftProtobufModuleName]
  let extraOptionImports = self.options.extraModuleImports
- let mappings = self.options.protoToModuleMappings
- .neededModules(forFile: self.descriptor) ?? []
- let allImports = (defaults + mappings + extraOptionImports + additional).sorted()
-
+ let allImports = (defaults + self.neededModules + extraOptionImports + additional).sorted()
  for module in allImports {
  self.printLine("import \(module)")
  }
  }
 }
+
+extension Generator: SwiftProtobufPluginLibrary.CodeGenerator {
+ private func resetAndPrintFile(
+ for descriptor: SwiftProtobufPluginLibrary.FileDescriptor
+ ) -> String {
+ self.namer = SwiftProtobufPluginLibrary.SwiftProtobufNamer(
+ currentFile: descriptor,
+ protoFileToModuleMappings: self.options.protoToModuleMappings
+ )
+ self.neededModules = self.options.protoToModuleMappings
+ .neededModules(forFile: descriptor) ?? []
+ self.services = descriptor.services
+ self.printer = SwiftProtobufPluginLibrary.CodePrinter(indent: " ".unicodeScalars)
+ self.printContent(for: descriptor)
+ return self.printer.content
+ }
+
+ public func generate(
+ files: [SwiftProtobufPluginLibrary.FileDescriptor],
+ parameter: any SwiftProtobufPluginLibrary.CodeGeneratorParameter,
+ protoCompilerContext _: any SwiftProtobufPluginLibrary.ProtoCompilerContext,
+ generatorOutputs: any SwiftProtobufPluginLibrary.GeneratorOutputs
+ ) throws {
+ self.options = try GeneratorOptions(commandLineParameters: parameter)
+ guard self.options.generateAsyncMethods || self.options.generateCallbackMethods else {
+ throw GeneratorError(
+ message: "Either async methods or callback methods must be enabled"
+ )
+ }
+
+ for descriptor in files where !descriptor.services.isEmpty {
+ try generatorOutputs.add(
+ fileName: FilePathComponents(path: descriptor.name).outputFilePath(
+ withExtension: self.outputFileExtension,
+ using: self.options.fileNaming
+ ),
+ contents: self.resetAndPrintFile(for: descriptor)
+ )
+ }
+ }
+
+ public var supportedEditionRange: ClosedRange<SwiftProtobuf.Google_Protobuf_Edition> {
+ let minEdition = max(
+ DescriptorSet.bundledEditionsSupport.lowerBound, Google_Protobuf_Edition.legacy
+ )
+ let maxEdition = min(
+ DescriptorSet.bundledEditionsSupport.upperBound, Google_Protobuf_Edition.edition2023
+ )
+ return minEdition...maxEdition
+ }
+
+ public var supportedFeatures: [
+ SwiftProtobufPluginLibrary.Google_Protobuf_Compiler_CodeGeneratorResponse.Feature
+ ] {
+ return [
+ .proto3Optional,
+ .supportsEditions,
+ ]
+ }
+}

Plugins/ConnectPluginUtilities/GeneratorOptions.swift

@@ -42,33 +42,6 @@ private enum CommandLineParameter: String {
  }
  }
  }
-
- static func parse(commandLineParameters: String) throws -> [(key: Self, value: String)] {
- return try commandLineParameters
- .components(separatedBy: ",")
- .compactMap { parameter in
- if parameter.isEmpty {
- return nil
- }
-
- guard let index = parameter.firstIndex(of: "=") else {
- throw Error.unknownParameter(string: parameter)
- }
-
- let rawKey = parameter[..<index].trimmingCharacters(in: .whitespacesAndNewlines)
- guard let key = Self(rawValue: rawKey) else {
- throw Error.unknownParameter(string: parameter)
- }
-
- let value = parameter[parameter.index(after: index)...]
- .trimmingCharacters(in: .whitespacesAndNewlines)
- if value.isEmpty {
- return nil
- }
-
- return (key, value)
- }
- }
 }
 
 /// A set of options that are used to customize generator outputs.
@@ -94,18 +67,23 @@ public struct GeneratorOptions {
  case `public` = "Public"
  }
 
- /// Initializes a set of generator options from the raw string representation of command line
+ static func empty() -> Self {
+ return .init()
+ }
+}
+
+extension GeneratorOptions {
+ /// Initializes a set of generator options from command line
  /// parameters (e.g., "Visibility=Internal,KeepMethodCasing=true").
  ///
- /// Handles trimming whitespace, and some parameters may be specified multiple times.
- ///
- /// - parameter commandLineParameters: The raw CLI parameters.
- public init(commandLineParameters: String) throws {
- let parsedParameters = try CommandLineParameter.parse(
- commandLineParameters: commandLineParameters
- )
- for (key, rawValue) in parsedParameters {
- switch key {
+ /// - parameter commandLineParameters: The CLI parameters.
+ public init(commandLineParameters: SwiftProtobufPluginLibrary.CodeGeneratorParameter) throws {
+ for (key, rawValue) in commandLineParameters.parsedPairs {
+ guard let parsedParameter = CommandLineParameter(rawValue: key) else {
+ throw CommandLineParameter.Error.unknownParameter(string: key)
+ }
+
+ switch parsedParameter {
  case .extraModuleImports:
  self.extraModuleImports.append(rawValue)
  continue
@@ -145,9 +123,7 @@ public struct GeneratorOptions {
  self.protoToModuleMappings = try ProtoFileToModuleMappings(path: rawValue)
  continue
  } catch let error {
- throw CommandLineParameter.Error.deserializationError(
- key: key.rawValue, error: error
- )
+ throw CommandLineParameter.Error.deserializationError(key: key, error: error)
  }
 
  case .swiftProtobufModuleName:
@@ -161,10 +137,7 @@ public struct GeneratorOptions {
  }
  }
 
- throw CommandLineParameter.Error.invalidParameterValue(
- key: key.rawValue,
- value: rawValue
- )
+ throw CommandLineParameter.Error.invalidParameterValue(key: key, value: rawValue)
  }
  }
 }