[#783]: feat(grpc): update GRPC plugin to RR `v2`

[#783]: feat(grpc): update GRPC plugin to RR `v2`

1 files changed, 114 insertions, 0 deletions

diff --git a/plugins/grpc/parser/parse.go b/plugins/grpc/parser/parse.go
new file mode 100644
index 00000000..d59b0927
--- /dev/null
+++ b/plugins/grpc/parser/parse.go
@@ -0,0 +1,114 @@
+package parser
+
+import (
+	"bytes"
+	"io"
+	"os"
+
+	pp "github.com/emicklei/proto"
+)
+
+// Service contains information about singular GRPC service.
+type Service struct {
+	// Package defines service namespace.
+	Package string
+
+	// Name defines service name.
+	Name string
+
+	// Methods list.
+	Methods []Method
+}
+
+// Method describes singular RPC method.
+type Method struct {
+	// Name is method name.
+	Name string
+
+	// StreamsRequest defines if method accept stream input.
+	StreamsRequest bool
+
+	// RequestType defines message name (from the same package) of method input.
+	RequestType string
+
+	// StreamsReturns defines if method streams result.
+	StreamsReturns bool
+
+	// ReturnsType defines message name (from the same package) of method return value.
+	ReturnsType string
+}
+
+// File parses given proto file or returns error.
+func File(file string, importPath string) ([]Service, error) {
+	reader, _ := os.Open(file)
+	defer reader.Close()
+
+	return parse(reader, importPath)
+}
+
+// Bytes parses string into proto definition.
+func Bytes(data []byte) ([]Service, error) {
+	return parse(bytes.NewBuffer(data), "")
+}
+
+func parse(reader io.Reader, importPath string) ([]Service, error) {
+	proto, err := pp.NewParser(reader).Parse()
+	if err != nil {
+		return nil, err
+	}
+
+	return parseServices(
+		proto,
+		parsePackage(proto),
+		importPath,
+	)
+}
+
+func parsePackage(proto *pp.Proto) string {
+	for _, e := range proto.Elements {
+		if p, ok := e.(*pp.Package); ok {
+			return p.Name
+		}
+	}
+
+	return ""
+}
+
+func parseServices(proto *pp.Proto, pkg string, importPath string) ([]Service, error) {
+	services := make([]Service, 0)
+
+	pp.Walk(proto, pp.WithService(func(service *pp.Service) {
+		services = append(services, Service{
+			Package: pkg,
+			Name:    service.Name,
+			Methods: parseMethods(service),
+		})
+	}))
+
+	pp.Walk(proto, func(v pp.Visitee) {
+		if i, ok := v.(*pp.Import); ok {
+			if im, err := File(importPath+"/"+i.Filename, importPath); err == nil {
+				services = append(services, im...)
+			}
+		}
+	})
+
+	return services, nil
+}
+
+func parseMethods(s *pp.Service) []Method {
+	methods := make([]Method, 0)
+	for _, e := range s.Elements {
+		if m, ok := e.(*pp.RPC); ok {
+			methods = append(methods, Method{
+				Name:           m.Name,
+				StreamsRequest: m.StreamsRequest,
+				RequestType:    m.RequestType,
+				StreamsReturns: m.StreamsReturns,
+				ReturnsType:    m.ReturnsType,
+			})
+		}
+	}
+
+	return methods
+}