feat(gengapic): add support for AutoPopulatedFields UUID4 (#1460)

internal/gengapic/generator.go

@@ -28,6 +28,7 @@ import (
 	"github.com/googleapis/gapic-generator-go/internal/pbinfo"
 	"github.com/googleapis/gapic-generator-go/internal/printer"
 	"github.com/googleapis/gapic-generator-go/internal/snippets"
+	"google.golang.org/genproto/googleapis/api/annotations"
 	"google.golang.org/genproto/googleapis/api/serviceconfig"
 	"google.golang.org/genproto/googleapis/gapic/metadata"
 	"google.golang.org/protobuf/encoding/protojson"
@@ -302,3 +303,37 @@ func (g *generator) nestedName(nested pbinfo.ProtoType) string {
 
 	return name
 }
+
+// autoPopulatedFields returns an array of FieldDescriptorProto pointers for the
+// given MethodDescriptorProto that are specified for auto-population per the
+// following restrictions:
+//
+// * The field is a top-level string field of a unary method's request message.
+// * The field is not annotated with google.api.field_behavior = REQUIRED.
+// * The field name is listed in google.api.publishing.method_settings.auto_populated_fields.
+// * The field is annotated with google.api.field_info.format = UUID4.
+func (g *generator) autoPopulatedFields(servName string, m *descriptor.MethodDescriptorProto) []*descriptor.FieldDescriptorProto {
+	var apfs []string
+	// Find the service config's AutoPopulatedFields entry by method name.
+	mfqn := g.fqn(m)
+	for _, s := range g.serviceConfig.GetPublishing().GetMethodSettings() {
+		if s.GetSelector() == mfqn {
+			apfs = s.AutoPopulatedFields
+			break
+		}
+	}
+	inType := g.descInfo.Type[m.GetInputType()].(*descriptor.DescriptorProto)
+	var validated []*descriptor.FieldDescriptorProto
+	for _, apf := range apfs {
+		field := getField(inType, apf)
+		// Do nothing and continue iterating unless all conditions above are met.
+		switch {
+		case field == nil:
+		case field.GetType() != fieldTypeString:
+		case isRequired(field):
+		case proto.GetExtension(field.GetOptions(), annotations.E_FieldInfo).(*annotations.FieldInfo).GetFormat() == annotations.FieldInfo_UUID4:
+			validated = append(validated, field)
+		}
+	}
+	return validated
+}

internal/gengapic/generator_test.go

@@ -0,0 +1,140 @@
+// Copyright 2024 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 (
+	"testing"
+
+	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+	"github.com/google/go-cmp/cmp"
+	"github.com/googleapis/gapic-generator-go/internal/pbinfo"
+	"google.golang.org/genproto/googleapis/api/annotations"
+	"google.golang.org/genproto/googleapis/api/serviceconfig"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/testing/protocmp"
+	"google.golang.org/protobuf/types/descriptorpb"
+)
+
+func TestAutoPopulatedFields(t *testing.T) {
+	optsUUID4 := &descriptorpb.FieldOptions{}
+	proto.SetExtension(optsUUID4, annotations.E_FieldInfo, &annotations.FieldInfo{Format: annotations.FieldInfo_UUID4})
+
+	optsIPV4 := &descriptorpb.FieldOptions{}
+	proto.SetExtension(optsIPV4, annotations.E_FieldInfo, &annotations.FieldInfo{Format: annotations.FieldInfo_IPV4})
+
+	optsRequiredAndUUID4 := &descriptorpb.FieldOptions{}
+	proto.SetExtension(optsRequiredAndUUID4, annotations.E_FieldBehavior, []annotations.FieldBehavior{annotations.FieldBehavior_REQUIRED})
+	proto.SetExtension(optsRequiredAndUUID4, annotations.E_FieldInfo, &annotations.FieldInfo{Format: annotations.FieldInfo_UUID4})
+
+	requestIDField := &descriptor.FieldDescriptorProto{
+		Name:           proto.String("request_id"),
+		Type:           typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+		Label:          labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+		Proto3Optional: proto.Bool(true),
+		Options:        optsUUID4,
+	}
+	inputType := &descriptor.DescriptorProto{
+		Name: proto.String("InputType"),
+		Field: []*descriptor.FieldDescriptorProto{
+			requestIDField,
+			{
+				Name:  proto.String("invalid_auto_populated_not_in_serviceconfig"),
+				Type:  typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+				Label: labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+			},
+			{
+				Name:  proto.String("invalid_auto_populated_no_annotation"),
+				Type:  typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+				Label: labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+			},
+			{
+				Name:    proto.String("invalid_auto_populated_required"),
+				Type:    typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+				Label:   labelp(descriptor.FieldDescriptorProto_LABEL_REQUIRED),
+				Options: optsRequiredAndUUID4,
+			},
+			{
+				Name:    proto.String("invalid_auto_populated_int"),
+				Type:    typep(descriptor.FieldDescriptorProto_TYPE_INT64),
+				Label:   labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+				Options: optsUUID4,
+			},
+			{
+				Name:    proto.String("invalid_auto_populated_ipv4"),
+				Type:    typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+				Label:   labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+				Options: optsIPV4,
+			},
+		},
+	}
+	outputType := &descriptor.DescriptorProto{
+		Name: proto.String("OutputType"),
+	}
+	file := &descriptor.FileDescriptorProto{
+		Package: proto.String("my.pkg"),
+		Options: &descriptor.FileOptions{
+			GoPackage: proto.String("mypackage"),
+		},
+	}
+	serv := &descriptor.ServiceDescriptorProto{
+		Name: proto.String("Foo"),
+	}
+
+	var g generator
+	g.opts = &options{
+		pkgName: "pkg",
+	}
+	g.imports = map[pbinfo.ImportSpec]bool{}
+
+	g.serviceConfig = &serviceconfig.Service{
+		Publishing: &annotations.Publishing{
+			MethodSettings: []*annotations.MethodSettings{
+				{
+					Selector: "my.pkg.Foo.GetOneThing",
+					AutoPopulatedFields: []string{
+						"request_id",
+						"invalid_auto_populated_no_annotation",
+						"invalid_auto_populated_required",
+						"invalid_auto_populated_int",
+						"invalid_auto_populated_ipv4",
+					},
+				},
+			},
+		},
+	}
+
+	commonTypes(&g)
+	g.descInfo.Type[".my.pkg."+inputType.GetName()] = inputType
+	g.descInfo.ParentFile[inputType] = file
+	g.descInfo.Type[".my.pkg."+outputType.GetName()] = outputType
+	g.descInfo.ParentFile[outputType] = file
+	g.descInfo.ParentFile[serv] = file
+
+	m := &descriptor.MethodDescriptorProto{
+		Name:       proto.String("GetOneThing"),
+		InputType:  proto.String(".my.pkg.InputType"),
+		OutputType: proto.String(".my.pkg.OutputType"),
+		Options:    &descriptor.MethodOptions{},
+	}
+	g.descInfo.ParentElement[m] = serv
+	serv.Method = []*descriptor.MethodDescriptorProto{m}
+
+	got := g.autoPopulatedFields(serv.GetName(), m)
+
+	want := []*descriptorpb.FieldDescriptorProto{requestIDField}
+	if diff := cmp.Diff(got, want, protocmp.Transform()); diff != "" {
+		t.Errorf("got(-),want(+):\n%s", diff)
+	}
+}

internal/gengapic/gengapic.go

@@ -348,6 +348,37 @@ func (g *generator) insertRequestHeaders(m *descriptor.MethodDescriptorProto, t
 	}
 }
 
+// insertAutoPopulatedFields generates the conditional initialization of any
+// default-value request fields (for the given method) that are specified for
+// auto-population by autoPopulatedFields.
+//
+// If the field value is not equal to default value at the time of sending the
+// request, implying it was set by the user, or if the field has explicit
+// presence and is set by the user, the field must not be auto-populated by
+// the client. Values automatically populated this way must be reused for
+// retries of the same request.
+func (g *generator) initializeAutoPopulatedFields(servName string, m *descriptor.MethodDescriptorProto) {
+	apfs := g.autoPopulatedFields(servName, m)
+	if len(apfs) == 0 {
+		return
+	}
+	g.imports[pbinfo.ImportSpec{Path: "github.com/google/uuid"}] = true
+	p := g.printf
+	for _, apf := range apfs {
+		f := buildAccessor(apf.GetName(), true)
+		if apf.GetProto3Optional() {
+			// Type will be *string if field has explicit presence.
+			p("if req != nil && req%s == nil {", f)
+			p("  req%s = proto.String(uuid.NewString())", f)
+		} else {
+			// Type will be string if field does not have explicit presence.
+			p(`if req != nil && req%s == "" {`, buildAccessor(apf.GetName(), false))
+			p("  req%s = uuid.NewString()", f)
+		}
+		p("}")
+	}
+}
+
 func buildAccessor(field string, rawFinal bool) string {
 	// Corner case if passed the result of strings.Join on an empty slice.
 	if field == "" {

internal/gengapic/gengapic_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/googleapis/gapic-generator-go/internal/snippets"
 	"github.com/googleapis/gapic-generator-go/internal/txtdiff"
 	"google.golang.org/genproto/googleapis/api/annotations"
+	"google.golang.org/genproto/googleapis/api/serviceconfig"
 	metadatapb "google.golang.org/genproto/googleapis/gapic/metadata"
 	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/proto"
@@ -149,6 +150,9 @@ func TestGenGRPCMethods(t *testing.T) {
 		Name: proto.String("NestedEnum"),
 	}
 
+	optsUUID4 := &descriptorpb.FieldOptions{}
+	proto.SetExtension(optsUUID4, annotations.E_FieldInfo, &annotations.FieldInfo{Format: annotations.FieldInfo_UUID4})
+
 	inputType := &descriptor.DescriptorProto{
 		Name: proto.String("InputType"),
 		Field: []*descriptor.FieldDescriptorProto{
@@ -183,6 +187,19 @@ func TestGenGRPCMethods(t *testing.T) {
 				Type:     typep(descriptor.FieldDescriptorProto_TYPE_ENUM),
 				TypeName: proto.String(".my.pkg.InputType.NestedEnum"),
 			},
+			{
+				Name:           proto.String("request_id"),
+				Type:           typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+				Label:          labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+				Proto3Optional: proto.Bool(true),
+				Options:        optsUUID4,
+			},
+			{
+				Name:    proto.String("non_proto3optional_request_id"),
+				Type:    typep(descriptor.FieldDescriptorProto_TYPE_STRING),
+				Label:   labelp(descriptor.FieldDescriptorProto_LABEL_OPTIONAL),
+				Options: optsUUID4,
+			},
 		},
 		EnumType: []*descriptor.EnumDescriptorProto{
 			nestedEnum,
@@ -321,6 +338,27 @@ func TestGenGRPCMethods(t *testing.T) {
 		"google.iam.v1.IAMPolicy":         iamPolicyMethods(),
 	}
 	g.imports = map[pbinfo.ImportSpec]bool{}
+
+	g.serviceConfig = &serviceconfig.Service{
+		Publishing: &annotations.Publishing{
+			MethodSettings: []*annotations.MethodSettings{
+				{
+					Selector: "my.pkg.Foo.GetEmptyThing",
+					AutoPopulatedFields: []string{
+						"request_id",
+					},
+				},
+				{
+					Selector: "my.pkg.Foo.GetOneThing",
+					AutoPopulatedFields: []string{
+						"request_id",
+						"non_proto3optional_request_id",
+					},
+				},
+			},
+		},
+	}
+
 	cpb := &conf.ServiceConfig{
 		MethodConfig: []*conf.MethodConfig{
 			{
@@ -371,6 +409,7 @@ func TestGenGRPCMethods(t *testing.T) {
 			},
 			imports: map[pbinfo.ImportSpec]bool{
 				{Path: "fmt"}:                            true,
+				{Path: "github.com/google/uuid"}:         true,
 				{Path: "net/url"}:                        true,
 				{Name: "mypackagepb", Path: "mypackage"}: true,
 			},
@@ -384,6 +423,7 @@ func TestGenGRPCMethods(t *testing.T) {
 			},
 			imports: map[pbinfo.ImportSpec]bool{
 				{Path: "fmt"}:                            true,
+				{Path: "github.com/google/uuid"}:         true,
 				{Path: "net/url"}:                        true,
 				{Name: "mypackagepb", Path: "mypackage"}: true,
 			},

internal/gengapic/gengrpc.go

@@ -104,6 +104,7 @@ func (g *generator) unaryGRPCCall(servName string, m *descriptor.MethodDescripto
 		lowcaseServName, m.GetName(), inSpec.Name, inType.GetName(), retTyp)
 
 	g.insertRequestHeaders(m, grpc)
+	g.initializeAutoPopulatedFields(servName, m)
 	g.appendCallOpts(m)
 
 	p("var resp *%s", retTyp)
@@ -142,6 +143,7 @@ func (g *generator) emptyUnaryGRPCCall(servName string, m *descriptor.MethodDesc
 		lowcaseServName, m.GetName(), inSpec.Name, inType.GetName())
 
 	g.insertRequestHeaders(m, grpc)
+	g.initializeAutoPopulatedFields(servName, m)
 	g.appendCallOpts(m)
 	p("err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {")
 	p("  var err error")

internal/gengapic/genrest.go

@@ -1020,6 +1020,7 @@ func (g *generator) emptyUnaryRESTCall(servName string, m *descriptor.MethodDesc
 	p("func (c *%s) %s(ctx context.Context, req *%s.%s, opts ...gax.CallOption) error {",
 		lowcaseServName, m.GetName(), inSpec.Name, inType.GetName())
 
+	g.initializeAutoPopulatedFields(servName, m)
 	// TODO(dovs): handle cancellation, metadata, osv.
 	// TODO(dovs): handle http headers
 	// TODO(dovs): handle deadlines
@@ -1113,6 +1114,7 @@ func (g *generator) unaryRESTCall(servName string, m *descriptor.MethodDescripto
 	p("func (c *%s) %s(ctx context.Context, req *%s.%s, opts ...gax.CallOption) (%s, error) {",
 		lowcaseServName, m.GetName(), inSpec.Name, inType.GetName(), retTyp)
 
+	g.initializeAutoPopulatedFields(servName, m)
 	// TODO(dovs): handle cancellation, metadata, osv.
 	// TODO(dovs): handle http headers
 	// TODO(dovs): handle deadlines?