Adding Memoize v1

src/decorators/index.ts

@@ -1,2 +1,3 @@
 export * from './exclude';
+export * from './memoize';
 export * from './pluck';

src/decorators/memoize.ts

@@ -0,0 +1,19 @@
+export function Memoize(): Function {
+    return function(target: any, propertyKey: string, descriptor: PropertyDescriptor) {
+        const originalMethod = descriptor.value;
+        descriptor.value = function(this: any, ...args: any[]) {
+            const reflectKey = `${JSON.stringify(this)}_${JSON.stringify(args)}_${propertyKey}`;
+            const hasReflectData = Reflect.hasMetadata(reflectKey, target);
+
+            if (hasReflectData) {
+                return Reflect.getMetadata(reflectKey, target)
+            } else {
+                const result = originalMethod.apply(this, args);
+                Reflect.defineMetadata(reflectKey, result, target);
+                return result;
+            }
+        }
+
+        return descriptor;
+    }
+}

src/index.ts

@@ -0,0 +1 @@
+import "reflect-metadata";

tests/decorators/memoize.spec.ts

@@ -0,0 +1,22 @@
+import 'reflect-metadata';
+import { Serde } from "src/serde";
+import { Memoize } from 'src/decorators';
+
+class MemoizeTestModel extends Serde<MemoizeTestModel> {
+    name: string;
+    @Memoize() doNameRandom(): string {
+        return this.name + (Math.random() * 10);
+    }
+}
+
+describe('@Memoize() Decorator', () => {
+    it('should remember...', () => {
+        const testModel = new MemoizeTestModel().deserialize({
+            name: 'test model',
+        });
+    
+        const result1 = testModel.doNameRandom();
+        const result2 = testModel.doNameRandom();
+        expect(result1).toBe(result2);
+    });
+});