feature(type): add easy way to serialize/deserialize values in serial…

…izer API

```
serializer.deserializeRegistry.registerClass(Date, (type, state) => {
    state.convert((v) => new Date(v));
});
```

packages/type/src/serializer.ts

@@ -498,6 +498,21 @@ export class TemplateState {
         }
     }
 
+    /**
+     * Adds a converter function that is executed on the current `this.accessor` value.
+     *
+     * @example
+     * ```typescript
+     * serializer.deserializeRegistry.registerClass(Date, (type, state) => {
+     *     state.convert((v) => new Date(v));
+     * });
+     * ```
+     */
+    convert(callback: (value: any) => any) {
+        const converter = this.setVariable('convert', callback);
+        this.addSetter(`${converter}(${this.accessor})`);
+    }
+
     /**
      * Stop executing next templates.
      */

packages/type/tests/serializer-api.spec.ts

@@ -69,5 +69,25 @@ test('new serializer', () => {
     });
 
     const user = deserialize<User>({ name: 'Peter', created: 0 }, undefined, mySerializer);
-    console.log('empty serializer', user);
+    expect(user.created).toBeInstanceOf(Date);
+});
+
+test('new serializer easy mode', () => {
+    class User {
+        name: string = '';
+        created: Date = new Date;
+    }
+
+    const mySerializer = new EmptySerializer('mySerializer');
+
+    mySerializer.deserializeRegistry.registerClass(Date, (type, state) => {
+        state.convert((v) => new Date(v));
+    });
+
+    mySerializer.serializeRegistry.registerClass(Date, (type, state) => {
+        state.convert((v) => v.toJSON());
+    });
+
+    const user = deserialize<User>({ name: 'Peter', created: 0 }, undefined, mySerializer);
+    expect(user.created).toBeInstanceOf(Date);
 });