[BAC-610] Add inline option to as_json_schema

lib/active_model/entity/schemas/json.rb

@@ -44,13 +44,29 @@ def enum_attributes
             end
           end
 
-          def json_schema_attribute_for(type)
+          def primitive_type_schema(type)
             return { type: :object } if type.type.nil?
             return { type: :number } if NUMBER_TYPES.include?(type.type)
             return { type: :string } if STRING_TYPES.include?(type.type)
             return { type: :boolean } if BOOLEAN_TYPES.include?(type.type)
-            return { "$ref": type.entity_type.json_schema_ref } if type.is_a?(Type::Entity)
-            return { items: json_schema_attribute_for(type.element_type), type: :array } if type.is_a?(Type::Array)
+
+            nil
+          end
+
+          def entity_schema_for(type, inline)
+            inline ? type.entity_type.as_json_schema(inline:) : { "$ref": type.entity_type.json_schema_ref }
+          end
+
+          def array_schema_for(type, inline)
+            { items: json_schema_attribute_for(type.element_type, inline:), type: :array }
+          end
+
+          def json_schema_attribute_for(type, inline: false)
+            schema = primitive_type_schema(type)
+            return schema if schema
+
+            return entity_schema_for(type, inline) if type.is_a?(Type::Entity)
+            return array_schema_for(type, inline) if type.is_a?(Type::Array)
 
             raise NotImplementedError
           end
@@ -68,14 +84,14 @@ def append_enum!(values, options)
             options[:enum] = values
           end
 
-          def as_json_schema
+          def as_json_schema(inline: false)
             type = :object
             description = meta_descriptions[nil].first
             required = required_attributes.map(&:name).map { _1.camelize(:lower) }
             nullable = nullable_attributes.map(&:name).index_by { _1.camelize(:lower) }
 
             attributes = attribute_types.transform_keys { _1.camelize(:lower) }
-            properties = attributes.transform_values { json_schema_attribute_for(_1) }
+            properties = attributes.transform_values { json_schema_attribute_for(_1, inline:) }
             enums = enum_attributes.transform_keys { _1.camelize(:lower) }
 
             properties.each do |name, options|

spec/active_model/entity/schemas/json_spec.rb

@@ -70,4 +70,57 @@ class Person
       properties:
     })
   end
+
+  context "with inline: true" do
+    it "inlines nested entity schemas" do
+      schema = SchemasTest::Person.as_json_schema(inline: true)
+
+      expect(schema[:properties]["fieldRole"]).to eq({
+        type: :object,
+        required: [],
+        properties: { "fieldName" => { type: :string } }
+      })
+    end
+
+    it "inlines array of entity schemas" do
+      schema = SchemasTest::Person.as_json_schema(inline: true)
+
+      expect(schema[:properties]["fieldRoles"]).to eq({
+        type: :array,
+        items: {
+          type: :object,
+          required: [],
+          properties: { "fieldName" => { type: :string } }
+        }
+      })
+    end
+
+    it "preserves nullable flag on inlined entities" do
+      schema = SchemasTest::Person.as_json_schema(inline: true)
+
+      expect(schema[:properties]["fieldNullableRole"]).to eq({
+        type: :object,
+        required: [],
+        properties: { "fieldName" => { type: :string } },
+        nullable: true
+      })
+    end
+
+    it "keeps primitive types unchanged" do
+      schema = SchemasTest::Person.as_json_schema(inline: true)
+
+      expect(schema[:properties]["fieldString"]).to eq({ type: :string })
+      expect(schema[:properties]["fieldInteger"]).to eq({ type: :number })
+      expect(schema[:properties]["fieldBoolean"]).to eq({ type: :boolean })
+    end
+
+    it "keeps array of primitives unchanged" do
+      schema = SchemasTest::Person.as_json_schema(inline: true)
+
+      expect(schema[:properties]["fieldIntegers"]).to eq({
+        type: :array,
+        items: { type: :number }
+      })
+    end
+  end
 end