Add sort_imports parameter for import statement order check (#13)

* Add sort_imports parameter for import statement order check

* Fail on unmatched parameters

Author: rvolosatovs

linter/linter.go

@@ -46,36 +46,41 @@ var linterErrors = []errorDescription{
 	"Use CamelCase (with an initial capital) for RPC method names.",
 }
 
+type Config struct {
+	ProtoFile   *descriptor.FileDescriptorProto
+	OutFile     io.WriteCloser
+	SortImports bool
+}
+
 // LintProtoFile takes a file name, proto file description, and a file.
 // It checks the file for errors and writes them to the output file
-func LintProtoFile(
-	protoFile *descriptor.FileDescriptorProto,
-	outFile io.WriteCloser,
-) (int, error) {
+func LintProtoFile(conf Config) (int, error) {
 	var (
 		errors      = protoBufErrors{}
-		protoSource = protoFile.GetSourceCodeInfo()
+		protoSource = conf.ProtoFile.GetSourceCodeInfo()
 	)
 
-	errors.lintImportOrder(protoFile.GetDependency())
+	if conf.SortImports {
+		errors.lintImportOrder(conf.ProtoFile.GetDependency())
+	}
 
-	for i, v := range protoFile.GetMessageType() {
+	for i, v := range conf.ProtoFile.GetMessageType() {
 		errors.lintProtoMessage(int32(i), pathMessage, []int32{}, v)
 	}
 
-	for i, v := range protoFile.GetEnumType() {
+	for i, v := range conf.ProtoFile.GetEnumType() {
 		errors.lintProtoEnumType(int32(i), pathEnumType, []int32{}, v)
 	}
 
-	for i, v := range protoFile.GetService() {
+	for i, v := range conf.ProtoFile.GetService() {
 		errors.lintProtoService(int32(i), v)
 	}
 	for _, v := range errors {
 		line, col := v.getSourceLineNumber(protoSource)
 		fmt.Fprintf(
-			outFile,
+			conf.OutFile,
 			"%s:%d:%d: '%s' - %s\n",
-			*protoFile.Name,
+			*conf.ProtoFile.Name,
 			line,
 			col,
 			v.errorString,

main.go

@@ -1,34 +1,59 @@
 package main
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 
 	"github.com/ckaznocha/protoc-gen-lint/linter"
 	"github.com/golang/protobuf/proto"
 	protoc "github.com/golang/protobuf/protoc-gen-go/plugin"
 )
 
+// SortImports represents the parameter, which can be specified to the tool invocation
+// to enable checking, whether the proto file imports are sorted alphabetically.
+const SortImports = "sort_imports"
+
 func panicOnError(err error) {
 	if err != nil {
 		panic(err)
 	}
 }
 
 func main() {
-
 	var (
 		totalErrors      int
 		generatorRequest protoc.CodeGeneratorRequest
+		parameters       struct {
+			SortImports bool
+		}
 	)
 
+	for _, p := range strings.Split(generatorRequest.GetParameter(), ",") {
+		switch p {
+		case SortImports:
+			parameters.SortImports = true
+		default:
+			fmt.Fprintf(os.Stderr, "Unmatched parameter: %s", p)
+			totalErrors++
+		}
+	}
+	if totalErrors != 0 {
+		os.Exit(1)
+	}
+
 	data, err := ioutil.ReadAll(os.Stdin)
 	panicOnError(err)
 
 	panicOnError(proto.Unmarshal(data, &generatorRequest))
 
 	for _, file := range generatorRequest.GetProtoFile() {
-		numErrors, err := linter.LintProtoFile(file, os.Stderr)
+		numErrors, err := linter.LintProtoFile(linter.Config{
+			ProtoFile:   file,
+			OutFile:     os.Stderr,
+			SortImports: parameters.SortImports,
+		})
 		panicOnError(err)
 		totalErrors += numErrors
 	}