chore(internal/snippets,gengapic): use sample values in tests (#1514)

Refactor internal/snippets/snippets_test.go and
internal/gengapic/example_test.go to use the internal/testing/sample
package.

For #1512

internal/gengapic/example_test.go

@@ -283,54 +283,33 @@ func TestExample(t *testing.T) {
 func TestGenSnippetFile(t *testing.T) {
 	var g generator
 	g.imports = map[pbinfo.ImportSpec]bool{}
-	g.serviceConfig = &serviceconfig.Service{
-		Apis: []*apipb.Api{
-			{Name: sample.ProtoServiceName},
-		},
-	}
-	g.snippetMetadata = snippets.NewMetadata(sample.ProtoPackagePath, sample.GoPackagePath, sample.GoPackageName)
+	g.serviceConfig = sample.ServiceConfig()
 
-	inputType := &descriptorpb.DescriptorProto{
-		Name: proto.String(sample.CreateRequest),
-	}
-	outputType := &descriptorpb.DescriptorProto{
-		Name: proto.String(sample.Resource),
-	}
+	serv := sample.Service()
+	g.snippetMetadata = snippets.NewMetadata(sample.ProtoPackagePath, sample.GoPackagePath, sample.GoPackageName)
+	g.snippetMetadata.AddService(serv.GetName(), sample.ServiceURL)
 
-	file := &descriptorpb.FileDescriptorProto{
-		Options: &descriptorpb.FileOptions{
-			GoPackage: proto.String(sample.GoProtoPackagePath),
-		},
-		Package: proto.String(sample.ProtoPackagePath),
-	}
+	inputType := sample.InputType(sample.CreateRequest)
+	outputType := sample.OutputType(sample.Resource)
 
 	files := []*descriptorpb.FileDescriptorProto{}
 	g.descInfo = pbinfo.Of(files)
+
+	file := sample.File()
 	for _, typ := range []*descriptorpb.DescriptorProto{
 		inputType, outputType,
 	} {
 		g.descInfo.Type[sample.DescriptorInfoTypeName(typ.GetName())] = typ
 		g.descInfo.ParentFile[typ] = file
 	}
 
-	serv := &descriptorpb.ServiceDescriptorProto{
-		Name: proto.String(sample.ServiceName),
-		Method: []*descriptorpb.MethodDescriptorProto{
-			{
-				Name:       proto.String(sample.CreateMethod),
-				InputType:  proto.String(sample.DescriptorInfoTypeName(sample.CreateRequest)),
-				OutputType: proto.String(sample.DescriptorInfoTypeName(sample.Resource)),
-			},
-		},
-	}
-
-	for _, tst := range []struct {
-		tstName string
+	for _, test := range []struct {
+		name    string
 		options options
 		imports map[pbinfo.ImportSpec]bool
 	}{
 		{
-			tstName: "snippet",
+			name: "snippet",
 			options: options{
 				pkgName:    "migration",
 				transports: []transport{grpc, rest},
@@ -341,20 +320,19 @@ func TestGenSnippetFile(t *testing.T) {
 			},
 		},
 	} {
-		t.Run(tst.tstName, func(t *testing.T) {
+		t.Run(test.name, func(t *testing.T) {
 			g.reset()
-			g.opts = &tst.options
-			g.snippetMetadata.AddService(serv.GetName(), sample.ServiceURL)
+			g.opts = &test.options
 			err := g.genSnippetFile(serv, serv.Method[0])
 			if err != nil {
 				t.Fatal(err)
 			}
 			g.commit(filepath.Join("cloud.google.com/go", "internal", "generated", "snippets", "bigquery", "main.go"), "main")
-			if diff := cmp.Diff(g.imports, tst.imports); diff != "" {
-				t.Errorf("TestExample(%s): imports got(-),want(+):\n%s", tst.tstName, diff)
+			if diff := cmp.Diff(test.imports, g.imports); diff != "" {
+				t.Errorf("TestExample(%s) imports mismatch: (-want +got):\n%s", test.name, diff)
 			}
 			got := *g.resp.File[0].Content + *g.resp.File[1].Content
-			txtdiff.Diff(t, got, filepath.Join("testdata", tst.tstName+".want"))
+			txtdiff.Diff(t, got, filepath.Join("testdata", test.name+".want"))
 		})
 	}
 }

internal/testing/sample/BUILD.bazel

@@ -5,4 +5,10 @@ go_library(
     srcs = ["sample.go"],
     importpath = "github.com/googleapis/gapic-generator-go/internal/testing/sample",
     visibility = ["//:__subpackages__"],
+    deps = [
+        "@org_golang_google_genproto_googleapis_api//serviceconfig",
+        "@org_golang_google_protobuf//proto",
+        "@org_golang_google_protobuf//types/descriptorpb",
+        "@org_golang_google_protobuf//types/known/apipb",
+    ],
 )

internal/testing/sample/sample.go

@@ -18,6 +18,11 @@ package sample
 
 import (
 	"fmt"
+
+	"google.golang.org/genproto/googleapis/api/serviceconfig"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/descriptorpb"
+	"google.golang.org/protobuf/types/known/apipb"
 )
 
 const (
@@ -139,3 +144,55 @@ const (
 func DescriptorInfoTypeName(typ string) string {
 	return fmt.Sprintf(".%s.%s", ProtoPackagePath, typ)
 }
+
+// ServiceConfig returns service config information.
+func ServiceConfig() *serviceconfig.Service {
+	return &serviceconfig.Service{
+		Apis: []*apipb.Api{
+			{Name: ProtoServiceName},
+		},
+	}
+}
+
+// Service returns a service descriptor using the sample values.
+func Service() *descriptorpb.ServiceDescriptorProto {
+	return &descriptorpb.ServiceDescriptorProto{
+		Name: proto.String(ServiceName),
+		Method: []*descriptorpb.MethodDescriptorProto{
+			{
+				Name:       proto.String(CreateMethod),
+				InputType:  proto.String(DescriptorInfoTypeName(CreateRequest)),
+				OutputType: proto.String(DescriptorInfoTypeName(Resource)),
+			},
+			{
+				Name:       proto.String(GetMethod),
+				InputType:  proto.String(DescriptorInfoTypeName(GetRequest)),
+				OutputType: proto.String(DescriptorInfoTypeName(Resource)),
+			},
+		},
+	}
+}
+
+// InputType returns an input type for a method.
+func InputType(input string) *descriptorpb.DescriptorProto {
+	return &descriptorpb.DescriptorProto{
+		Name: proto.String(input),
+	}
+}
+
+// OutputType returns an output type for a method.
+func OutputType(output string) *descriptorpb.DescriptorProto {
+	return &descriptorpb.DescriptorProto{
+		Name: proto.String(output),
+	}
+}
+
+// File returns a proto file.
+func File() *descriptorpb.FileDescriptorProto {
+	return &descriptorpb.FileDescriptorProto{
+		Options: &descriptorpb.FileOptions{
+			GoPackage: proto.String(GoProtoPackagePath),
+		},
+		Package: proto.String(ProtoPackagePath),
+	}
+}