Subtraiting tests

src/tests-inheritance.ts

@@ -1,7 +1,7 @@
-import { extendsAndExpresses, trait } from "./trait-inheritance"
+import { expresses, trait } from "./trait-inheritance"
 
 
-const Identified = <ID>() =>
+const Identifiable = <ID>() =>
     trait(Parent => {
         abstract class Identified extends Parent {
             abstract id: ID
@@ -9,11 +9,25 @@ const Identified = <ID>() =>
             equals(el: Identified) {
                 return this.id === el.id
             }
+
+            constructor(...args: any[]) {
+                super(...args)
+                console.log("Identified constructor")
+            }
         }
 
         return Identified
     })
 
+const ImplementsIdentifiable = <ID>(defaultID: ID) =>
+    trait(Parent => {
+        abstract class ImplementsIdentifiable extends Identifiable<ID>()(Parent) {
+            id: ID = defaultID
+        }
+
+        return ImplementsIdentifiable
+    })
+
 
 const Permissible = trait(Parent => {
     abstract class Permissible extends Parent {
@@ -30,14 +44,16 @@ const Permissible = trait(Parent => {
 })
 
 
-const UserProto = extendsAndExpresses(class {}, [
-    Identified<bigint>(),
+const UserProto = expresses(
+    // Identifiable<bigint>(),
+    ImplementsIdentifiable(0n),
     Permissible,
-] as const)
+)
 
 class User extends UserProto {
-    constructor(readonly id: bigint) {
+    constructor(id: bigint) {
         super()
+        this.id = id
     }
 }
 

src/trait-inheritance.ts

@@ -38,13 +38,12 @@ export function trait<
 
 
 export function extendsAndExpresses<
-    C      extends AbstractClass<any, any>,
+    C      extends AbstractClass<any>,
     Traits extends readonly Trait<any>[],
 >(
     extend: C,
     traits: Traits,
 ) {
-
     return traits.reduce(
         (previous, trait) => trait(previous),
         extend,
@@ -71,5 +70,12 @@ export function extendsAndExpresses<
             >
         >
     )
-
+}
+
+export function expresses<
+    Traits extends readonly Trait<any>[],
+>(
+    ...traits: Traits
+) {
+    return extendsAndExpresses(Object, traits)
 }