generator-go-sdk: add nullable support for resource manager sdk

tools/generator-go-sdk/internal/generator/templater_models.go

@@ -561,15 +561,31 @@ func (c modelsTemplater) codeForMarshalFunctions(data GeneratorData) (*string, e
 	output := ""
 
 	readOnlyFields := make([]string, 0)
+	nullableFields := make([]string, 0)
 	for _, field := range c.model.Fields {
 		if field.ReadOnly {
 			readOnlyFields = append(readOnlyFields, field.JsonName)
 		}
+		if field.ObjectDefinition.Nullable {
+			nullableFields = append(nullableFields, field.JsonName)
+		}
 	}
 	sort.Strings(readOnlyFields)
 
 	// Only output a Marshal function when there are discriminated value or read-only fields to customize
-	if c.model.DiscriminatedValue == nil && len(readOnlyFields) == 0 {
+	if c.model.DiscriminatedValue == nil && len(readOnlyFields) == 0 && len(nullableFields) == 0 {
+		return &output, nil
+	}
+
+	// add nullable support for resource manager sdk without touching the field type
+	if data.sourceType == models.ResourceManagerSourceDataType && len(nullableFields) > 0 && c.model.DiscriminatedValue == nil {
+		output += fmt.Sprintf(`
+var _ json.Marshaler = %[1]s{}
+
+func (s %[1]s) MarshalJSON() ([]byte, error) {
+	return nullable.MarshalNullableStruct(s)
+}
+`, c.name)
 		return &output, nil
 	}
 

tools/importer-rest-api-specs/internal/components/apidefinitions/parser/dataworkarounds/workaround_nullable.go

@@ -0,0 +1,79 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package dataworkarounds
+
+import (
+	"fmt"
+
+	sdkModels "github.com/hashicorp/pandora/tools/data-api-sdk/v1/models"
+)
+
+var _ workaround = nullableWorkaround{}
+
+// this is a common workaround for nullable fields
+// we can add a workaround later as simple as below before we add nullable support for all resources:
+// fleetNullableWorkaround = newNullableWorkaround("AzureFleet", []string{"2024-11-01"}, "Fleets", "VirtualMachineScaleSetOSProfile", "LinuxConfiguration")
+// recoveryNullableWorkaround = newNullableWorkaround("RecoveryServicesSiteRecovery", []string{"2024-10-01"}, "ReplicationProtectedItems", "DisableProtectionInputProperties", "ReplicationProviderInput")
+type nullableWorkaround struct {
+	serviceName string
+	apiVersions []string
+	resource    string
+	model       string
+	field       string
+}
+
+func newNullableWorkaround(serviceName string, apiVersion []string, resource, model, field string) workaround {
+	return nullableWorkaround{
+		serviceName: serviceName,
+		apiVersions: apiVersion,
+		resource:    resource,
+		model:       model,
+		field:       field,
+	}
+}
+
+func (n nullableWorkaround) inApiVersion(apiVersion string) bool {
+	if len(n.apiVersions) == 0 {
+		return true
+	}
+
+	for _, version := range n.apiVersions {
+		if version == apiVersion {
+			return true
+		}
+	}
+	return false
+}
+
+func (n nullableWorkaround) IsApplicable(serviceName string, apiVersion sdkModels.APIVersion) bool {
+	return serviceName == n.serviceName && n.inApiVersion(apiVersion.APIVersion)
+}
+
+func (n nullableWorkaround) Name() string {
+	return fmt.Sprintf("Nullable / %s.%s", n.serviceName, n.resource)
+}
+
+func (n nullableWorkaround) Process(input sdkModels.APIVersion) (*sdkModels.APIVersion, error) {
+	resource, ok := input.Resources[n.resource]
+	if !ok {
+		return nil, fmt.Errorf("expected a Resource named `%s`", n.resource)
+	}
+
+	profile, ok := resource.Models[n.model]
+	if !ok {
+		return nil, fmt.Errorf("resource %s expected a Model named `%s`", n.resource, n.model)
+	}
+
+	conf, ok := profile.Fields[n.field]
+	if !ok {
+		return nil, fmt.Errorf("model %s.%s expected a Field named `%s`", n.resource, n.model, n.field)
+	}
+	conf.ObjectDefinition.Nullable = true
+
+	profile.Fields[n.field] = conf
+	resource.Models[n.model] = profile
+	input.Resources[n.resource] = resource
+
+	return &input, nil
+}