Trait refactoring

src/trait.ts

@@ -3,30 +3,30 @@ import { AbstractClass, Class, Opaque } from "type-fest"
 import { StaticMembers } from "./util"
 
 
-// type AddAbstractMembersToImpl<
-//     Impl            extends Class<object, []>,
-//     AbstractMembers extends object,
-// > = (
-//     Class<
-//         InstanceType<Impl> & AbstractMembers,
-//         ConstructorParameters<Impl>
-//     > &
-//     StaticMembers<Impl>
-// )
+type AddAbstractToImplClass<
+    Impl     extends Class<object, []>,
+    Abstract extends object,
+> = (
+    Class<
+        InstanceType<Impl> & Abstract,
+        ConstructorParameters<Impl>
+    > &
+    StaticMembers<Impl>
+)
 
-type RemoveAbstractMembersFromImplInstance<
+type RemoveAbstractFromImplInstance<
     ImplInstanceWithAbstractMembers extends AbstractMembers,
     AbstractMembers                 extends object,
 > = (
     Omit<ImplInstanceWithAbstractMembers, keyof AbstractMembers>
 )
 
-type RemoveAbstractMembersFromImplClass<
+type RemoveAbstractFromImplClass<
     ImplWithAbstractMembers extends Class<AbstractMembers, []>,
     AbstractMembers         extends object,
 > = (
     Class<
-        RemoveAbstractMembersFromImplInstance<
+        RemoveAbstractFromImplInstance<
             InstanceType<ImplWithAbstractMembers>,
             AbstractMembers
         >,
@@ -40,13 +40,13 @@ type RemoveAbstractMembersFromImplClass<
 export type TraitTag = "@thilawyn/traitify-ts/Trait"
 
 export type Trait<
-    AbstractMembers         extends object,
-    ImplWithAbstractMembers extends Class<AbstractMembers, []>,
+    Abstract extends object,
+    Impl     extends Class<object, []>,
 > = (
     Opaque<{
         readonly apply: TraitApplier<
-            AbstractMembers,
-            ImplWithAbstractMembers
+            Abstract,
+            AddAbstractToImplClass<Impl, Abstract>
         >
     }, TraitTag>
 )
@@ -62,11 +62,8 @@ export interface TraitAbstractMembersFn extends Fn {
 }
 
 export type TraitImplClass<T> = (
-    T extends Trait<infer AbstractMembers, infer ImplWithAbstractMembers>
-        ? RemoveAbstractMembersFromImplClass<
-            ImplWithAbstractMembers,
-            AbstractMembers
-        >
+    T extends Trait<any, infer Impl>
+        ? Impl
         : never
 )
 
@@ -75,11 +72,8 @@ export interface TraitImplClassFn extends Fn {
 }
 
 export type TraitImplInstance<T> = (
-    T extends Trait<infer AbstractMembers, infer ImplWithAbstractMembers>
-        ? RemoveAbstractMembersFromImplInstance<
-            InstanceType<ImplWithAbstractMembers>,
-            AbstractMembers
-        >
+    T extends Trait<any, infer Impl>
+        ? InstanceType<Impl>
         : never
 )
 
@@ -88,8 +82,8 @@ export interface TraitImplInstanceFn extends Fn {
 }
 
 export type TraitClass<T> = (
-    T extends Trait<any, infer ImplWithAbstractMembers>
-        ? ImplWithAbstractMembers
+    T extends Trait<infer Abstract, infer Impl>
+        ? AddAbstractToImplClass<Impl, Abstract>
         : never
 )
 
@@ -98,8 +92,10 @@ export interface TraitClassFn extends Fn {
 }
 
 export type TraitInstance<T> = (
-    T extends Trait<any, infer ImplWithAbstractMembers>
-        ? InstanceType<ImplWithAbstractMembers>
+    T extends Trait<infer Abstract, infer Impl>
+        ? InstanceType<
+            AddAbstractToImplClass<Impl, Abstract>
+        >
         : never
 )
 
@@ -111,22 +107,22 @@ export interface TraitInstanceFn extends Fn {
 export type TraitApplierSuperTag = "@thilawyn/traitify-ts/TraitApplierSuper"
 
 export type TraitApplier<
-    AbstractMembers         extends object,
-    ImplWithAbstractMembers extends Class<AbstractMembers, []>,
+    Abstract         extends object,
+    ImplWithAbstract extends Class<Abstract, []>,
 > = (
-    (Super: Opaque<AbstractClass<AbstractMembers>, TraitApplierSuperTag>) => (
-        Opaque<ImplWithAbstractMembers, TraitApplierSuperTag>
+    (Super: Opaque<AbstractClass<Abstract>, TraitApplierSuperTag>) => (
+        Opaque<ImplWithAbstract, TraitApplierSuperTag>
     )
 )
 
 export function trait<
-    AbstractMembers extends object = {}
+    Abstract extends object = {}
 >(): (
-    <ImplWithAbstractMembers extends Class<AbstractMembers, []>>(
-        apply: TraitApplier<AbstractMembers, ImplWithAbstractMembers>
+    <ImplWithAbstract extends Class<Abstract, []>>(
+        apply: TraitApplier<Abstract, ImplWithAbstract>
     ) => Trait<
-        AbstractMembers,
-        ImplWithAbstractMembers
+        Abstract,
+        RemoveAbstractFromImplClass<ImplWithAbstract, Abstract>
     >
 ) {
     return apply => ({ apply }) as any