productcatalogservice: implementation

src/productcatalogservice/genproto.sh

@@ -0,0 +1,6 @@
+#!/bin/bash -e
+
+PATH=$PATH:$GOPATH/bin
+protodir=../../pb
+
+protoc --go_out=plugins=grpc:genproto -I $protodir $protodir/demo.proto

src/productcatalogservice/server.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"strings"
+
+	pb "./genproto"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+var port = flag.Int("port", 3550, "port to listen at")
+
+var catalog = []*pb.Product{
+	{Id: 1, Name: "shirt", Description: "nice shirt", Picture: "picture1", PriceUsd: &pb.MoneyAmount{Decimal: 53}},
+	{Id: 2, Name: "pants", Description: "nice pants", Picture: "picture2", PriceUsd: &pb.MoneyAmount{Decimal: 81}},
+	{Id: 3, Name: "hat", Description: "nice hat", Picture: "picture3", PriceUsd: &pb.MoneyAmount{Decimal: 20}},
+}
+
+func main() {
+	flag.Parse()
+	run(*port)
+	select {}
+}
+
+func run(port int) string {
+	l, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
+	if err != nil {
+		log.Fatal(err)
+	}
+	srv := grpc.NewServer()
+	pb.RegisterProductCatalogServiceServer(srv, &productCatalog{})
+	go srv.Serve(l)
+	return l.Addr().String()
+}
+
+type productCatalog struct{}
+
+func (p *productCatalog) ListProducts(context.Context, *pb.Empty) (*pb.ListProductsResponse, error) {
+	return &pb.ListProductsResponse{Products: catalog}, nil
+}
+
+func (p *productCatalog) GetProduct(ctx context.Context, req *pb.GetProductRequest) (*pb.Product, error) {
+	for _, p := range catalog {
+		if req.Id == p.Id {
+			return p, nil
+		}
+	}
+	return nil, status.Errorf(codes.NotFound, "no product with ID %d", req.Id)
+}
+
+func (p *productCatalog) SearchProducts(ctx context.Context, req *pb.SearchProductsRequest) (*pb.SearchProductsResponse, error) {
+	// Intepret query as a substring match in name or description.
+	var ps []*pb.Product
+	for _, p := range catalog {
+		if strings.Contains(p.Name, req.Query) || strings.Contains(p.Description, req.Query) {
+			ps = append(ps, p)
+		}
+	}
+	return &pb.SearchProductsResponse{Results: ps}, nil
+}

src/productcatalogservice/server_test.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"context"
+	"testing"
+
+	pb "./genproto"
+	"github.com/golang/protobuf/proto"
+	"github.com/google/go-cmp/cmp"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func TestServer(t *testing.T) {
+	ctx := context.Background()
+	addr := run(0)
+	conn, err := grpc.Dial(addr, grpc.WithInsecure())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	client := pb.NewProductCatalogServiceClient(conn)
+	res, err := client.ListProducts(ctx, &pb.Empty{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if diff := cmp.Diff(res.Products, catalog, cmp.Comparer(proto.Equal)); diff != "" {
+		t.Error(diff)
+	}
+
+	got, err := client.GetProduct(ctx, &pb.GetProductRequest{Id: 2})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want := catalog[1]; !proto.Equal(got, want) {
+		t.Errorf("got %v, want %v", got, want)
+	}
+	_, err = client.GetProduct(ctx, &pb.GetProductRequest{Id: -1})
+	if got, want := status.Code(err), codes.NotFound; got != want {
+		t.Errorf("got %s, want %s", got, want)
+	}
+
+	sres, err := client.SearchProducts(ctx, &pb.SearchProductsRequest{Query: "nice"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if diff := cmp.Diff(sres.Results, catalog, cmp.Comparer(proto.Equal)); diff != "" {
+		t.Error(diff)
+	}
+}