0.1.1 (#8)

Co-authored-by: Julien Valverdé <julien.valverde@mailo.com>
Reviewed-on: https://git.jvalver.de/Thilawyn/thilatrait/pulls/8

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@thilawyn/thilatrait",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "type": "module",
   "publishConfig": {
     "registry": "https://git.jvalver.de/api/packages/thilawyn/npm/"
@@ -35,7 +35,7 @@
     "bun-types": "latest",
     "npm-check-updates": "^16.14.12",
     "npm-sort": "^0.0.4",
-    "rollup": "^4.9.2",
+    "rollup": "^4.9.4",
     "rollup-plugin-cleanup": "^3.2.1",
     "rollup-plugin-ts": "^3.4.5",
     "tsx": "^4.7.0",

src/index.ts

@@ -5,7 +5,7 @@ import { AbstractClass, AbstractConstructor, Opaque, UnionToIntersection } from
  * Represents the static members of a class.
  * @template C - The class type.
  */
-export type StaticMembers<C> = {
+type StaticMembers<C> = {
     [Key in keyof C as Key extends "prototype" ? never : Key]: C[Key]
 }
 
@@ -28,17 +28,26 @@ export type Trait<
 export type TraitApplier<
     C extends AbstractClass<any>
 > =
-    (Parent: AbstractConstructor<any>) => C
+    (Parent: AbstractConstructor<object>) => C
 
 /**
- * Unwraps the type of the class from a given trait.
+ * Returns the class type of a trait.
  * @template T - The trait type.
  */
-export type UnwrapTraitC<T> =
+export type TraitClass<T> =
     T extends Trait<infer C>
         ? C
         : never
 
+/**
+ * Returns the instance type of a trait.
+ * @template T - The trait type.
+ */
+export type TraitInstance<T> =
+    T extends Trait<infer C>
+        ? InstanceType<C>
+        : never
+
 
 /**
  * Creates a trait using the provided trait applier function.
@@ -90,7 +99,7 @@ export type UnwrapTraitC<T> =
  *     trait(Parent => {
  *         abstract class ImplementsIdentifiable extends extendsAndExpresses(
  *             Parent,
- *             [Identifiable<ID>()],
+ *             Identifiable<ID>(),
  *         ) {
  *             id: ID = defaultID
  *
@@ -123,7 +132,10 @@ export function trait<
  * @example
  * Extends a superclass and applies traits:
  * ```ts
- * class User extends extendsAndExpresses(Entity, [Identifiable<bigint>(), Permissible]) {
+ * class User extends extendsAndExpresses(Entity,
+ *     Identifiable<bigint>(),
+ *     Permissible,
+ * ) {
  *     readonly id: bigint
  *
  *     constructor(id: bigint) {
@@ -138,7 +150,7 @@ export function extendsAndExpresses<
     Traits extends readonly Trait<any>[],
 >(
     extend: C,
-    traits: Traits,
+    ...traits: Traits
 ) {
     return traits.reduce(
         (previous, trait) => trait(previous),
@@ -147,10 +159,8 @@ export function extendsAndExpresses<
         AbstractClass<
             InstanceType<C> &
             UnionToIntersection<
-                InstanceType<
+                TraitInstance<
-                    UnwrapTraitC<
+                    Traits[number]
-                        Traits[number]
-                    >
                 >
             >,
 
@@ -160,7 +170,7 @@ export function extendsAndExpresses<
         StaticMembers<C> &
         StaticMembers<
             UnionToIntersection<
-                UnwrapTraitC<
+                TraitClass<
                     Traits[number]
                 >
             >
@@ -191,5 +201,5 @@ export function expresses<
 >(
     ...traits: Traits
 ) {
-    return extendsAndExpresses(Object, traits)
+    return extendsAndExpresses(Object, ...traits)
 }

src/tests.ts

@@ -23,7 +23,7 @@ const ImplementsIdentifiable = <ID>(defaultID: ID) =>
     trait(Parent => {
         abstract class ImplementsIdentifiable extends extendsAndExpresses(
             Parent,
-            [Identifiable<ID>()],
+            Identifiable<ID>(),
         ) {
             id: ID = defaultID