fix(sidekick): Fixes several issues with oneof main setter samples (#2589)

- Uses the right import for the oneof group
- Takes boxing of the oneof message variants into account.
- Messages variants are now deprioritized for selection as a oneof
example variant.
- Makes the values shown match the ones used in other samples

This also removes the sample generation for when the example one of
varinat that's use on the main setter is repeated or map, as that needs
bigger improvements that will be done in a subsequent PR. Note that the
samples for each specific variant, including repeated and map, continue
to be generated.

Author: amanda-tarafa

internal/sidekick/internal/rust/annotate.go

@@ -396,11 +396,16 @@ type oneOfAnnotation struct {
 	QualifiedName string
 	// The fully qualified name, relative to `codec.modulePath`. Typically this
 	// is the `QualifiedName` with the `crate::model::` prefix removed.
+	// This is always relative to `ScopeInExamples`.
 	RelativeName string
 	// The Rust `struct` that contains this oneof, fully qualified
 	StructQualifiedName string
-	FieldType           string
-	DocLines            []string
+	// The scope to show in examples. For messages in external packages
+	// this is basically `QualifiedName`. For messages in the current package
+	// this includes `modelAnnotations.PackageName`.
+	ScopeInExamples string
+	FieldType       string
+	DocLines        []string
 	// The best field to show in a oneof related samples.
 	// Non deprecated fields are preferred, then scalar, repeated, map fields
 	// in that order.
@@ -991,12 +996,22 @@ func (c *codec) annotateOneOf(oneof *api.OneOf, message *api.Message, model *api
 	qualifiedName := fmt.Sprintf("%s::%s", scope, enumName)
 	relativeEnumName := strings.TrimPrefix(qualifiedName, c.modulePath+"::")
 	structQualifiedName := fullyQualifiedMessageName(message, c.modulePath, model.PackageName, c.packageMapping)
+	scopeInExamples := scope
+	if strings.HasPrefix(scope, c.modulePath+"::") {
+		scopeInExamples = strings.Replace(scope, c.modulePath, fmt.Sprintf("%s::model", c.packageNamespace(model)), 1)
+	}
 
 	bestField := slices.MaxFunc(oneof.Fields, func(f1 *api.Field, f2 *api.Field) int {
 		if f1.Deprecated == f2.Deprecated {
 			if f1.Map == f2.Map {
 				if f1.Repeated == f2.Repeated {
-					return 0
+					if f1.MessageType != nil && f2.MessageType == nil {
+						return -1
+					} else if f1.MessageType == nil && f2.MessageType != nil {
+						return 1
+					} else {
+						return 0
+					}
 				} else if f1.Repeated {
 					return -1
 				} else {
@@ -1021,6 +1036,7 @@ func (c *codec) annotateOneOf(oneof *api.OneOf, message *api.Message, model *api
 		QualifiedName:       qualifiedName,
 		RelativeName:        relativeEnumName,
 		StructQualifiedName: structQualifiedName,
+		ScopeInExamples:     scopeInExamples,
 		FieldType:           fmt.Sprintf("%s::%s", scope, enumName),
 		DocLines:            c.formatDocComments(oneof.Documentation, oneof.ID, model.State, message.Scopes()),
 		ExampleField:        bestField,

internal/sidekick/internal/rust/annotate_test.go

@@ -495,6 +495,7 @@ func TestOneOfAnnotations(t *testing.T) {
 		QualifiedName:       "crate::model::message::Type",
 		RelativeName:        "message::Type",
 		StructQualifiedName: "crate::model::Message",
+		ScopeInExamples:     "google_cloud_test::model::message",
 		FieldType:           "crate::model::message::Type",
 		DocLines:            []string{"/// Say something clever about this oneof."},
 		ExampleField:        singular,
@@ -644,6 +645,7 @@ func TestOneOfConflictAnnotations(t *testing.T) {
 		QualifiedName:       "crate::model::message::NestedThingOneOf",
 		RelativeName:        "message::NestedThingOneOf",
 		StructQualifiedName: "crate::model::Message",
+		ScopeInExamples:     "google_cloud_test::model::message",
 		FieldType:           "crate::model::message::NestedThingOneOf",
 		DocLines:            []string{"/// Say something clever about this oneof."},
 		ExampleField:        singular,
@@ -1877,6 +1879,13 @@ func TestOneOfExampleFieldSelection(t *testing.T) {
 		Name:    "message_field",
 		ID:      ".test.Message.message_field",
 		Typez:   api.MESSAGE_TYPE,
+		TypezID: ".test.OneMessage",
+		IsOneOf: true,
+	}
+	another_message_field := &api.Field{
+		Name:    "another_message_field",
+		ID:      ".test.Message.another_message_field",
+		Typez:   api.MESSAGE_TYPE,
 		TypezID: ".test.AnotherMessage",
 		IsOneOf: true,
 	}
@@ -1891,6 +1900,16 @@ func TestOneOfExampleFieldSelection(t *testing.T) {
 			fields: []*api.Field{deprecated, map_field, repeated, scalar, message_field},
 			want:   scalar,
 		},
+		{
+			name:   "no primitives",
+			fields: []*api.Field{deprecated, map_field, repeated, message_field},
+			want:   message_field,
+		},
+		{
+			name:   "only scalars and messages",
+			fields: []*api.Field{message_field, scalar, another_message_field},
+			want:   scalar,
+		},
 		{
 			name:   "no scalars",
 			fields: []*api.Field{deprecated, map_field, repeated},
@@ -1922,7 +1941,17 @@ func TestOneOfExampleFieldSelection(t *testing.T) {
 				Fields:  tc.fields,
 				OneOfs:  []*api.OneOf{group},
 			}
-			model := api.NewTestAPI([]*api.Message{message}, []*api.Enum{}, []*api.Service{})
+			oneMesage := &api.Message{
+				Name:    "OneMessage",
+				ID:      ".test.OneMessage",
+				Package: "test",
+			}
+			anotherMessage := &api.Message{
+				Name:    "AnotherMessage",
+				ID:      ".test.AnotherMessage",
+				Package: "test",
+			}
+			model := api.NewTestAPI([]*api.Message{message, oneMesage, anotherMessage}, []*api.Enum{}, []*api.Service{})
 			api.CrossReference(model)
 			codec := createRustCodec()
 			annotateModel(model, codec)

internal/sidekick/internal/rust/templates/common/setter_preamble/oneof.mustache

@@ -24,28 +24,20 @@ limitations under the License.
 {{#Codec.ExampleField}}
 {{#IsString}}
 /// # use {{Parent.Codec.NameInExamples}};
-/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}("value".to_string())));
+/// use {{Group.Codec.ScopeInExamples}};
+/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}("example".to_string())));
 {{/IsString}}
 {{#IsLikeInt}}
 /// # use {{Parent.Codec.NameInExamples}};
-/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}(123)));
+/// use {{Group.Codec.ScopeInExamples}};
+/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}(42)));
 {{/IsLikeInt}}
 {{#IsObject}}
 /// # use {{Parent.Codec.NameInExamples}};
+/// use {{Group.Codec.ScopeInExamples}};
 /// use {{MessageType.Codec.NameInExamples}};
-/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}({{MessageType.Codec.Name}}::default()/* use setters */)));
+/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}({{MessageType.Codec.Name}}::default().into())));
 {{/IsObject}}
-{{#Repeated}}
-/// # use {{Parent.Codec.NameInExamples}};
-/// use {{MessageType.Codec.NameInExamples}};
-/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}(vec![{{MessageType.Codec.Name}}::default()])));
-{{/Repeated}}
-{{#Map}}
-/// # use {{Parent.Codec.NameInExamples}};
-/// use {{KeyField.MessageType.Codec.NameInExamples}};
-/// use {{ValueField.MessageType.Codec.NameInExamples}};
-/// let x = {{Parent.Codec.Name}}::new().set_{{Group.Codec.SetterName}}(Some({{{Group.Codec.RelativeName}}}::{{Codec.BranchName}}(std::collections::HashMap::from([({{KeyField.MessageType.Codec.Name}}::default(), {{ValueField.MessageType.Codec.Name}}::default())]))));
-{{/Map}}
 {{/Codec.ExampleField}}
 /// ```
 {{/ModelCodec.GenerateSetterSamples}}