feat: Implement notnull Attribute

src/Core/Attribute.ts

@@ -320,6 +320,9 @@ export class LazyAttribute<T = any> extends AttributeBase<T, () => Nullable<T>,
 
   private _valuate(raw: any): () => Nullable<T> {
     if (raw === null) {
+      if (this.declaration.notNull) {
+        throw new Error("this Attribute must not be null");
+      }
       return () => null;
     }
     const v = this.converter.convert(raw, this, this.converterContext);
@@ -511,6 +514,9 @@ export class StandardAttribute<T = any> extends AttributeBase<T, T, IStandardAtt
 
   private _valuate(raw: any): null | T {
     if (raw === null) {
+      if (this.declaration.notNull) {
+        throw new Error("this Attribute must not be null");
+      }
       return null;
     }
     const v = this.converter.convert(raw, this, this.converterContext);

src/Interface/IAttributeDeclaration.ts

@@ -1,22 +1,24 @@
 import { Name } from "../Tool/Types";
 import { IConverterDeclaration, ILazyConverterDeclaration, IStandardConverterDeclaration } from "./IAttributeConverterDeclaration";
 
+export interface IAttributeDeclarationBase {
+  default: any;
+  notNull?: boolean;
+  [parameters: string]: any;
+}
+
 /**
  * interface for attribute declaration
  */
-export interface IStandardAttributeDeclaration<T = any> {
+export interface IStandardAttributeDeclaration<T = any> extends IAttributeDeclarationBase {
   converter: Name | IStandardConverterDeclaration<T>;
-  default: any;
-  [parameters: string]: any;
 }
 
 /**
  * interface for lazy attribute declaration
  */
-export interface ILazyAttributeDeclaration<T = any> {
+export interface ILazyAttributeDeclaration<T = any> extends IAttributeDeclarationBase {
   converter: Name | ILazyConverterDeclaration<T>;
-  default: any;
-  [parameters: string]: any;
 }
 
 export type IAttributeDeclaration<T= any> = IStandardAttributeDeclaration<T> | ILazyAttributeDeclaration<T>;