feat: add support for bulk resource ID filtering in ReadRelationships

internal/services/v1/relationships.go

@@ -577,9 +577,21 @@ func validateRelationshipsFilter(ctx context.Context, filter *v1.RelationshipFil
 		}
 	}
 
-	// Ensure the resource ID and the resource ID prefix are not set at the same time.
-	if filter.OptionalResourceId != "" && filter.OptionalResourceIdPrefix != "" {
-		return NewInvalidFilterErr("resource_id and resource_id_prefix cannot be set at the same time", filter.String())
+	// Use counter-based validation for mutual exclusion of resource ID fields
+	resourceIdFieldsCount := 0
+	if filter.OptionalResourceId != "" {
+		resourceIdFieldsCount++
+	}
+	if filter.OptionalResourceIdPrefix != "" {
+		resourceIdFieldsCount++
+	}
+	if len(filter.OptionalResourceIds) > 0 {
+		resourceIdFieldsCount++
+	}
+
+	// Ensure only one resource ID field type is set at a time
+	if resourceIdFieldsCount > 1 {
+		return NewInvalidFilterErr("only one of resource_id, resource_id_prefix, or resource_ids can be set at the same time", filter.String())
 	}
 
 	// Ensure that at least one field is set.
@@ -590,6 +602,7 @@ func checkIfFilterIsEmpty(filter *v1.RelationshipFilter) error {
 	if filter.ResourceType == "" &&
 		filter.OptionalResourceId == "" &&
 		filter.OptionalResourceIdPrefix == "" &&
+		len(filter.OptionalResourceIds) == 0 &&
 		filter.OptionalRelation == "" &&
 		filter.OptionalSubjectFilter == nil {
 		return NewInvalidFilterErr("at least one field must be set", filter.String())

pkg/datastore/datastore.go

@@ -331,9 +331,25 @@ func RelationshipsFilterFromCoreFilter(filter *core.RelationshipFilter) (Relatio
 // RelationshipsFilterFromPublicFilter constructs a datastore RelationshipsFilter from an API-defined RelationshipFilter.
 func RelationshipsFilterFromPublicFilter(filter *v1.RelationshipFilter) (RelationshipsFilter, error) {
 	var resourceIds []string
+
+	// Handle resource ID fields with mutual exclusion logic
+	resourceIdFieldsCount := 0
 	if filter.OptionalResourceId != "" {
+		resourceIdFieldsCount++
 		resourceIds = []string{filter.OptionalResourceId}
 	}
+	if filter.OptionalResourceIdPrefix != "" {
+		resourceIdFieldsCount++
+	}
+	if len(filter.OptionalResourceIds) > 0 {
+		resourceIdFieldsCount++
+		resourceIds = filter.OptionalResourceIds
+	}
+
+	// Ensure only one resource ID field type is set
+	if resourceIdFieldsCount > 1 {
+		return RelationshipsFilter{}, fmt.Errorf("cannot specify more than one of OptionalResourceId, OptionalResourceIdPrefix, or OptionalResourceIds")
+	}
 
 	var subjectsSelectors []SubjectsSelector
 	if filter.OptionalSubjectFilter != nil {
@@ -360,10 +376,6 @@ func RelationshipsFilterFromPublicFilter(filter *v1.RelationshipFilter) (Relatio
 		})
 	}
 
-	if filter.OptionalResourceId != "" && filter.OptionalResourceIdPrefix != "" {
-		return RelationshipsFilter{}, fmt.Errorf("cannot specify both OptionalResourceId and OptionalResourceIDPrefix")
-	}
-
 	if filter.ResourceType == "" && filter.OptionalRelation == "" && len(resourceIds) == 0 && filter.OptionalResourceIdPrefix == "" && len(subjectsSelectors) == 0 {
 		return RelationshipsFilter{}, fmt.Errorf("at least one filter field must be set")
 	}

pkg/datastore/datastore_test.go

@@ -131,6 +131,87 @@ func TestRelationshipsFilterFromPublicFilter(t *testing.T) {
 			},
 			"",
 		},
+		{
+			"bulk resource ids single",
+			&v1.RelationshipFilter{
+				ResourceType:        "sometype",
+				OptionalResourceIds: []string{"id1"},
+				OptionalRelation:    "somerel",
+			},
+			RelationshipsFilter{
+				OptionalResourceType:     "sometype",
+				OptionalResourceIds:      []string{"id1"},
+				OptionalResourceRelation: "somerel",
+			},
+			"",
+		},
+		{
+			"bulk resource ids multiple",
+			&v1.RelationshipFilter{
+				ResourceType:        "sometype",
+				OptionalResourceIds: []string{"id1", "id2", "id3"},
+				OptionalRelation:    "somerel",
+			},
+			RelationshipsFilter{
+				OptionalResourceType:     "sometype",
+				OptionalResourceIds:      []string{"id1", "id2", "id3"},
+				OptionalResourceRelation: "somerel",
+			},
+			"",
+		},
+		{
+			"bulk resource ids with subject filter",
+			&v1.RelationshipFilter{
+				ResourceType:        "sometype",
+				OptionalResourceIds: []string{"id1", "id2"},
+				OptionalRelation:    "somerel",
+				OptionalSubjectFilter: &v1.SubjectFilter{
+					SubjectType: "someothertype",
+				},
+			},
+			RelationshipsFilter{
+				OptionalResourceType:     "sometype",
+				OptionalResourceIds:      []string{"id1", "id2"},
+				OptionalResourceRelation: "somerel",
+				OptionalSubjectsSelectors: []SubjectsSelector{
+					{
+						OptionalSubjectType: "someothertype",
+					},
+				},
+			},
+			"",
+		},
+		{
+			"error: resource_id and resource_ids both set",
+			&v1.RelationshipFilter{
+				ResourceType:        "sometype",
+				OptionalResourceId:  "single_id",
+				OptionalResourceIds: []string{"id1", "id2"},
+			},
+			RelationshipsFilter{},
+			"cannot specify more than one of OptionalResourceId, OptionalResourceIdPrefix, or OptionalResourceIds",
+		},
+		{
+			"error: resource_id_prefix and resource_ids both set",
+			&v1.RelationshipFilter{
+				ResourceType:             "sometype",
+				OptionalResourceIdPrefix: "prefix_",
+				OptionalResourceIds:      []string{"id1", "id2"},
+			},
+			RelationshipsFilter{},
+			"cannot specify more than one of OptionalResourceId, OptionalResourceIdPrefix, or OptionalResourceIds",
+		},
+		{
+			"error: all three resource id fields set",
+			&v1.RelationshipFilter{
+				ResourceType:             "sometype",
+				OptionalResourceId:       "single_id",
+				OptionalResourceIdPrefix: "prefix_",
+				OptionalResourceIds:      []string{"id1", "id2"},
+			},
+			RelationshipsFilter{},
+			"cannot specify more than one of OptionalResourceId, OptionalResourceIdPrefix, or OptionalResourceIds",
+		},
 	}
 
 	for _, test := range tests {