feat(core): handle RefElement serialization in toValue serializer (#3901)

Refs #3894

Author: char0n

packages/apidom-core/src/transformers/serializers/value/ast/ephemeral-array.ts

@@ -1,9 +1,9 @@
 class EphemeralArray {
-  type = 'EphemeralArray';
+  public readonly type = 'EphemeralArray';
 
-  content: any[] = [];
+  protected readonly content: any[] = [];
 
-  reference: any = undefined;
+  protected readonly reference: any = undefined;
 
   constructor(content: any[]) {
     this.content = content;

packages/apidom-core/src/transformers/serializers/value/ast/ephemeral-object.ts

@@ -1,9 +1,9 @@
 class EphemeralObject {
-  type = 'EphemeralObject';
+  public readonly type = 'EphemeralObject';
 
-  content: any[] = [];
+  protected readonly content: any[] = [];
 
-  reference: any = undefined;
+  protected readonly reference: any = undefined;
 
   constructor(content: any[]) {
     this.content = content;

packages/apidom-core/src/transformers/serializers/value/index.ts

@@ -85,8 +85,14 @@ class Visitor {
     return null;
   }
 
-  public RefElement(element: RefElement): unknown {
-    return element.toValue();
+  public RefElement(element: RefElement, ...rest: unknown[]) {
+    const ancestors = rest[3] as (Element | EphemeralArray | EphemeralObject)[];
+
+    if (ancestors[ancestors.length - 1]?.type === 'EphemeralObject') {
+      return Symbol.for('delete-node');
+    }
+
+    return String(element.toValue());
   }
 
   public LinkElement(element: LinkElement): string {

packages/apidom-core/test/transformers/serializers/value.ts

@@ -154,6 +154,18 @@ describe('serializers', function () {
           assert.deepEqual(serialized, { ref: 'id' });
         });
       });
+
+      context('and included instead of MemberElement', function () {
+        specify('should remove from serialization', function () {
+          const object = new ObjectElement({
+            a: 'b',
+          });
+          object.content.push(new RefElement('id'));
+          const serialized = serializer(object);
+
+          assert.deepEqual(serialized, { a: 'b' });
+        });
+      });
     });
 
     context('given LinkElement', function () {