Introduce SwiftProtobufModuleName option in protoc plugin to match the one in SwiftProtobuf plugin (#1220)

Sources/protoc-gen-grpc-swift/Generator.swift

@@ -90,7 +90,7 @@ class Generator {
     let moduleNames = [
       self.options.gRPCModuleName,
       "NIO",
-      "SwiftProtobuf",
+      self.options.swiftProtobufModuleName,
     ]
 
     for moduleName in (moduleNames + self.options.extraModuleImports).sorted() {

Sources/protoc-gen-grpc-swift/options.swift

@@ -60,6 +60,7 @@ final class GeneratorOptions {
   private(set) var fileNaming = FileNaming.FullPath
   private(set) var extraModuleImports: [String] = []
   private(set) var gRPCModuleName = "GRPC"
+  private(set) var swiftProtobufModuleName = "SwiftProtobuf"
 
   init(parameter: String?) throws {
     for pair in GeneratorOptions.parseParameter(string: parameter) {
@@ -132,6 +133,13 @@ final class GeneratorOptions {
           throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
         }
 
+      case "SwiftProtobufModuleName":
+        if !pair.value.isEmpty {
+          self.swiftProtobufModuleName = pair.value
+        } else {
+          throw GenerationError.invalidParameterValue(name: pair.key, value: pair.value)
+        }
+
       default:
         throw GenerationError.unknownParameter(name: pair.key)
       }

docs/plugin.md

@@ -100,6 +100,15 @@ to be specified. The value, if not specified, defaults to "GRPC".
 workaround for CocoaPods users who may end up with a transitive dependency on
 the gRPC core C library whose module name is also "GRPC".*
 
+### SwiftProtobufModuleName
+
+ The **SwiftProtobufModuleName** option allows the name of the SwiftProtobuf 
+ runtime module to be specified. The value, if not specified, defaults to 
+ "SwiftProtobuf".
+
+ *Note: most users will not need to use this option. Introduced to match 
+ the option that exists in [SwiftProtobuf][swift-protobuf-module-name].
+
 ## Specifying Options
 
 To pass extra parameters to the plugin, use a comma-separated parameter list
@@ -121,3 +130,4 @@ protoc <your proto> --grpc-swift_opt=Client=true,Server=false --grpc-swift_out=.
 [protocol-buffers]: https://developers.google.com/protocol-buffers/docs/overview
 [swift-protobuf-filenaming]: https://github.com/apple/swift-protobuf/blob/master/Documentation/PLUGIN.md#generation-option-filenaming---naming-of-generated-sources
 [swift-protobuf-module-mappings]: https://github.com/apple/swift-protobuf/blob/master/Documentation/PLUGIN.md#generation-option-protopathmodulemappings---swift-module-names-for-proto-paths
+[swift-protobuf-module-name]: https://github.com/apple/swift-protobuf/commit/9df381f72ff22062080d434e9c2f68e71ee44298#diff-1b08f0a80bd568509049d851b8d8af90d1f2db3cd8711eaba974b5380cd59bf3