feat: configurable empty relationship type

Author: mattkhan

lib/anchor/config.rb

@@ -4,14 +4,16 @@ class Config
       :field_case,
       :use_active_record_presence,
       :use_active_record_comment,
-      :infer_nullable_relationships_as_optional
+      :infer_nullable_relationships_as_optional,
+      :empty_relationship_type
 
     def initialize
       @ar_column_to_type = nil
       @field_case = nil
       @use_active_record_presence = nil
       @use_active_record_comment = nil
       @infer_nullable_relationships_as_optional = nil
+      @empty_relationship_type = nil
     end
   end
 end

lib/anchor/type_script/resource.rb

@@ -4,9 +4,14 @@ def express(context: {}, include_all_fields:, exclude_fields:)
       included_fields = schema_fetchable_fields(context:, include_all_fields:)
       included_fields -= exclude_fields if exclude_fields
 
+      relationships_property = anchor_relationships_property(included_fields:)
+      if relationships_property.nil? && Anchor.config.empty_relationship_type
+        relationships_property = Anchor::Types::Property.new(:relationships, Anchor.config.empty_relationship_type.call)
+      end
+
       properties = [id_property, type_property] +
         Array.wrap(anchor_attributes_properties(included_fields:)) +
-        Array.wrap(anchor_relationships_property(included_fields:)) +
+        Array.wrap(relationships_property) +
         [anchor_meta_property].compact + [anchor_links_property].compact
 
       expression = Anchor::TypeScript::Serializer.type_string(Anchor::Types::Object.new(properties))

lib/anchor/type_script/serializer.rb

@@ -35,6 +35,7 @@ def serialize_literal(value)
       end
 
       def serialize_object(type, depth)
+        return "{}" if type.properties.empty?
         properties = type.properties.flat_map do |p|
           [
             p.description && "/** #{p.description} */",

lib/anchor/types.rb

@@ -18,11 +18,13 @@ class Object
       attr_reader :properties
 
       def initialize(properties)
-        @properties = properties
+        @properties = properties || []
       end
 
       class << self
-        attr_reader :properties
+        def properties
+          @properties ||= []
+        end
 
         def property(name, type, optional: nil, description: nil)
           @properties ||= []

spec/example/config/initializers/anchor.rb

@@ -9,6 +9,8 @@ module Anchor
       return Types::Literal.new("never") if column.name == "loljk"
       Types::Inference::ActiveRecord::SQL.default_ar_column_to_type(column)
     }
+
+    c.empty_relationship_type = -> { Anchor::Types::Object }
   end
 end
 

spec/example/test/files/all_fields_false_schema.ts

@@ -12,6 +12,7 @@ export type Comment = {
   id: number;
   type: "comments";
   createdAt: string;
+  relationships: {};
 };
 
 export type User = {
@@ -87,6 +88,7 @@ export type Exhaustive = {
   resourceOverridden: unknown;
   /** This is a comment. */
   withComment: Maybe<string>;
+  relationships: {};
   meta: {
     some_count: number;
     extra_stuff: string;

spec/example/test/files/excluded_fields_schema.ts

@@ -12,6 +12,7 @@ export type Comment = {
   id: number;
   type: "comments";
   createdAt: string;
+  relationships: {};
 };
 
 export type User = {
@@ -85,6 +86,7 @@ export type Exhaustive = {
   resourceOverridden: unknown;
   /** This is a comment. */
   withComment: Maybe<string>;
+  relationships: {};
   meta: {
     some_count: number;
     extra_stuff: string;

spec/example/test/files/schema.ts

@@ -95,6 +95,7 @@ export type Exhaustive = {
   resourceOverridden: unknown;
   /** This is a comment. */
   withComment: Maybe<string>;
+  relationships: {};
   meta: {
     some_count: number;
     extra_stuff: string;

spec/example/test/files/test_schema.ts

@@ -92,6 +92,7 @@ export type Exhaustive = {
   resourceOverridden: unknown;
   /** This is a comment. */
   withComment: Maybe<string>;
+  relationships: {};
   meta: {
     some_count: number;
     extra_stuff: string;