internal/gengapic: surface google.api.resource patterns in snippets

internal/gengapic/example.go

@@ -20,6 +20,7 @@ import (
 
 	longrunning "cloud.google.com/go/longrunning/autogen/longrunningpb"
 	"github.com/googleapis/gapic-generator-go/internal/pbinfo"
+	"google.golang.org/genproto/googleapis/api/annotations"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/descriptorpb"
 )
@@ -96,35 +97,40 @@ func (g *generator) exampleMethod(pkgName, servName string, m *descriptorpb.Meth
 	return nil
 }
 
+// TODO(codyoss): This if can be removed once the public protos
+// have been migrated to their new package. This should be soon after this
+// code is merged.
+func temporarilyHardcodeInSpecPath(inSpec pbinfo.ImportSpec) pbinfo.ImportSpec {
+	if inSpec.Path == "google.golang.org/genproto/googleapis/longrunning" {
+		inSpec.Path = "cloud.google.com/go/longrunning/autogen/longrunningpb"
+	} else if inSpec.Path == "google.golang.org/genproto/googleapis/iam/v1" {
+		inSpec.Path = "cloud.google.com/go/iam/apiv1/iampb"
+	}
+	return inSpec
+}
+
 func (g *generator) exampleMethodBody(pkgName, servName string, m *descriptorpb.MethodDescriptorProto) error {
+	p := g.printf
+
 	if m.GetClientStreaming() != m.GetServerStreaming() {
 		// TODO(pongad): implement this correctly.
 		return nil
 	}
 
-	p := g.printf
-
+	// m.GetInputType() returns a string in the format
+	// `.google.cloud.<service>.<version>.<method>`.
 	inType := g.descInfo.Type[m.GetInputType()]
 	if inType == nil {
-		return fmt.Errorf("cannot find type %q, malformed descriptor?", m.GetInputType())
+		return fmt.Errorf("exampleMethodBody: cannot find type %q, malformed descriptor?", m.GetInputType())
 	}
 
 	inSpec, err := g.descInfo.ImportSpec(inType)
 	if err != nil {
 		return err
 	}
-	// TODO(codyoss): This if can be removed once the public protos
-	// have been migrated to their new package. This should be soon after this
-	// code is merged.
-	if inSpec.Path == "google.golang.org/genproto/googleapis/longrunning" {
-		inSpec.Path = "cloud.google.com/go/longrunning/autogen/longrunningpb"
-	} else if inSpec.Path == "google.golang.org/genproto/googleapis/iam/v1" {
-		inSpec.Path = "cloud.google.com/go/iam/apiv1/iampb"
-	}
-
-	httpInfo := getHTTPInfo(m)
-
+	inSpec = temporarilyHardcodeInSpecPath(inSpec)
 	g.imports[inSpec] = true
+
 	// Pick the first transport for simplicity. We don't need examples
 	// of each method for both transports when they have the same surface.
 	t := g.opts.transports[0]
@@ -134,14 +140,19 @@ func (g *generator) exampleMethodBody(pkgName, servName string, m *descriptorpb.
 	}
 	g.exampleInitClient(pkgName, s)
 
+	// name := "projects/{project-id}/books/{book}"
+	a := inType.(*descriptorpb.DescriptorProto)
+	requestName := g.constructRequestName(a)
 	if !m.GetClientStreaming() && !m.GetServerStreaming() {
 		p("")
 		p("req := &%s.%s{", inSpec.Name, inType.GetName())
 		p("  // TODO: Fill request struct fields.")
 		p("  // See https://pkg.go.dev/%s#%s.", inSpec.Path, inType.GetName())
+		p("  Name: %q", requestName)
 		p("}")
 	}
 
+	httpInfo := getHTTPInfo(m)
 	pf, _, err := g.getPagingFields(m)
 	if err != nil {
 		return err
@@ -159,10 +170,27 @@ func (g *generator) exampleMethodBody(pkgName, servName string, m *descriptorpb.
 	} else {
 		g.exampleUnaryCall(m)
 	}
-
 	return nil
 }
 
+func (g *generator) constructRequestName(method *descriptorpb.DescriptorProto) string {
+	a := getResourceReference(method)
+	parts := strings.Split(a, ".")
+	typName := fmt.Sprintf(".google.cloud.%s.v1.%s", parts[0], strings.Split(parts[2], "/")[1])
+	inType2 := g.descInfo.Type[typName]
+	b := inType2.(*descriptorpb.DescriptorProto)
+
+	// GetResource
+	r := proto.GetExtension(b.GetOptions(), annotations.E_Resource)
+	resource := r.(*annotations.ResourceDescriptor)
+	return fmt.Sprintf("projects/{project-id}/%s", resource.Pattern[0])
+}
+
+func getResourceReference(inType *descriptorpb.DescriptorProto) string {
+	r := proto.GetExtension(inType.Field[0].GetOptions(), annotations.E_ResourceReference)
+	return r.(*annotations.ResourceReference).Type
+}
+
 func (g *generator) exampleLROCall(m *descriptorpb.MethodDescriptorProto) {
 	p := g.printf
 	retVars := "resp, err :="

internal/gengapic/pattern_test.go

@@ -0,0 +1,127 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gengapic
+
+import (
+	"fmt"
+	"path/filepath"
+	"testing"
+
+	"github.com/googleapis/gapic-generator-go/internal/pbinfo"
+	"github.com/googleapis/gapic-generator-go/internal/snippets"
+	"github.com/googleapis/gapic-generator-go/internal/testing/sample"
+	"github.com/googleapis/gapic-generator-go/internal/txtdiff"
+	"google.golang.org/genproto/googleapis/api/annotations"
+	"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"
+)
+
+// TestExampleMethodBody_Pattern tests
+// https://github.com/googleapis/gapic-generator-go/issues/1372, using the
+// example in
+// https://github.com/googleapis/gapic-generator-go/issues/1372#issuecomment-1633101248.
+func TestExampleMethodBody_Pattern(t *testing.T) {
+	g := generator{
+		serviceConfig: &serviceconfig.Service{
+			Apis: []*apipb.Api{
+				{
+					Name: fmt.Sprintf("%s.%s", sample.ProtoPackagePath, sample.ServiceName),
+				},
+			},
+		},
+		imports: map[pbinfo.ImportSpec]bool{
+			{Path: "context"}: true,
+			{Name: sample.GoProtoPackageName, Path: sample.GoProtoPackagePath}: true,
+		},
+		snippetMetadata: snippets.NewMetadata(sample.ProtoPackagePath, sample.GoPackagePath, sample.GoPackageName),
+		descInfo:        pbinfo.Of([]*descriptorpb.FileDescriptorProto{}),
+		opts: &options{
+			pkgName:    sample.GoPackageName,
+			transports: []transport{grpc, rest},
+		},
+	}
+	g.snippetMetadata.AddService(sample.ServiceName, sample.ProtoPackagePath)
+
+	serv := &descriptorpb.ServiceDescriptorProto{
+		Name: proto.String(sample.ServiceName),
+		Method: []*descriptorpb.MethodDescriptorProto{
+			{
+				Name:       proto.String(sample.GetRequest),
+				InputType:  proto.String(sample.DescriptorInfoTypeName(sample.GetRequest)),
+				OutputType: proto.String(sample.DescriptorInfoTypeName(sample.Resource)),
+			},
+		},
+	}
+
+	name := "name"
+	inputType := &descriptorpb.DescriptorProto{
+		Name: proto.String(sample.GetRequest),
+		Field: []*descriptorpb.FieldDescriptorProto{
+			{
+				Name:    &name,
+				Options: &descriptorpb.FieldOptions{},
+			},
+		},
+	}
+	proto.SetExtension(
+		inputType.Field[0].GetOptions(),
+		annotations.E_ResourceReference,
+		&annotations.ResourceReference{
+			Type: sample.ResourceType,
+		},
+	)
+
+	outputType := &descriptorpb.DescriptorProto{
+		Name: proto.String(sample.Resource),
+		Field: []*descriptorpb.FieldDescriptorProto{
+			{
+				Name: &name,
+			},
+		},
+		Options: &descriptorpb.MessageOptions{},
+	}
+	proto.SetExtension(
+		outputType.GetOptions(),
+		annotations.E_Resource,
+		&annotations.ResourceDescriptor{
+			Type:    sample.ResourceType,
+			Pattern: []string{sample.ResourcePattern},
+		})
+
+	for _, typ := range []*descriptorpb.DescriptorProto{
+		inputType,
+		outputType,
+	} {
+		typName := sample.DescriptorInfoTypeName(typ.GetName())
+		g.descInfo.Type[typName] = typ
+		g.descInfo.ParentFile[typ] = &descriptorpb.FileDescriptorProto{
+			Options: &descriptorpb.FileOptions{
+				GoPackage: proto.String(sample.GoProtoPackagePath),
+			},
+			Package: proto.String(sample.ProtoPackagePath),
+		}
+	}
+
+	for _, m := range serv.Method {
+		if err := g.genSnippetFile(serv, m); err != nil {
+			t.Fatal(err)
+		}
+	}
+	g.commit(filepath.Join("cloud.google.com/go", "internal", "generated", "snippets", sample.GoPackageName, "main.go"), "main")
+	got := *g.resp.File[1].Content
+	txtdiff.Diff(t, got, filepath.Join("testdata", "snippet_Library.want"))
+}

internal/gengapic/snippets.go

@@ -100,7 +100,7 @@ func (g *generator) genAndCommitSnippets(s *descriptorpb.ServiceDescriptorProto)
 	return nil
 }
 
-// genSnippetFile generates a single RPC snippet by leveraging exampleMethodBody in gengapic/example.go.
+// genSnippetFile generates a RPC snippet for a given method body.
 func (g *generator) genSnippetFile(s *descriptorpb.ServiceDescriptorProto, m *descriptorpb.MethodDescriptorProto) error {
 	regionTag := g.snippetMetadata.RegionTag(s.GetName(), m.GetName())
 	g.headerComment(fmt.Sprintf("[START %s]", regionTag))

internal/gengapic/testdata/snippet_Library.want

@@ -0,0 +1,27 @@
+func main() {
+	ctx := context.Background()
+	// This snippet has been automatically generated and should be regarded as a code template only.
+	// It will require modifications to work:
+	// - It may require correct/in-range values for request initialization.
+	// - It may require specifying regional endpoints when creating the service client as shown in:
+	//   https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options
+	c, err := library.NewClient(ctx)
+	if err != nil {
+		// TODO: Handle error.
+	}
+	defer c.Close()
+
+	req := &librarypb.GetBookRequest{
+		// TODO: Fill request struct fields.
+		// See https://pkg.go.dev/cloud.google.com/go/library/apiv1/librarypb#GetBookRequest.
+		Name: "projects/{project-id}/books/{book}"
+	}
+	resp, err := c.GetBookRequest(ctx, req)
+	if err != nil {
+		// TODO: Handle error.
+	}
+	// TODO: Use resp.
+	_ = resp
+}
+
+// [END google_v1_generated_LibraryService_GetBookRequest_sync]

internal/testing/sample/sample.go

@@ -75,8 +75,24 @@ const (
 	//
 	// Example:
 	// https://pkg.go.dev/cloud.google.com/go/bigquery/migration/apiv2/migrationpb#MigrationWorkflow
-	// https://github.com/googleapis/googleapis/blob/master/google/cloud/bigquery/migration/v2alpha/migration_entities.proto#L38
+	// https://github.com/googleapis/googleapis/blob/f7df662a24c56ecaab79cb7d808fed4d2bb4981d/google/cloud/bigquery/migration/v2/migration_entities.proto#L36
 	Resource = "MigrationWorkflow"
+
+	// ResourceType is the type of the `google.api.resource` option.
+	//
+	// Example:
+	// https://github.com/googleapis/googleapis/blob/f7df662a24c56ecaab79cb7d808fed4d2bb4981d/google/cloud/bigquery/migration/v2/migration_entities.proto#L38
+	//
+	// It is also the value of the resource reference type in the GetRequest
+	// for `google.api.resource_reference`.
+	// https://github.com/googleapis/googleapis/blob/f7df662a24c56ecaab79cb7d808fed4d2bb4981d/google/cloud/bigquery/migration/v2/migration_service.proto#L132
+	ResourceType = "bigquerymigration.googleapis.com/MigrationWorkflow"
+
+	// ResourcePattern is the pattern of the `google.api.resource` option.
+	//
+	// Example:
+	// https://github.com/googleapis/googleapis/blob/f7df662a24c56ecaab79cb7d808fed4d2bb4981d/google/cloud/bigquery/migration/v2/migration_entities.proto#L39
+	ResourcePattern = "projects/{project}/locations/{location}/workflows/{workflow}"
 )
 
 const (