Work

src/effect/schema/class/Class.ts

@@ -0,0 +1,20 @@
+import { Schema as S } from "@effect/schema"
+import type { Annotations, Struct } from "@effect/schema/Schema"
+import type { HasFields } from "./util"
+
+
+export function Class<Self>(identifier: string) {
+    return <Fields extends Struct.Fields>(
+        fieldsOr:      Fields | HasFields<Fields>,
+        annotations?:  Annotations.Schema<Self>,
+    ) =>
+        S.Class<Self>(identifier)(fieldsOr, annotations) as S.Class<
+            Self,
+            Fields,
+            Struct.Encoded<Fields>,
+            Struct.Context<Fields>,
+            Struct.Constructor<Fields>,
+            {},
+            {}
+        >
+}

src/effect/schema/class/MobXObservable.ts

@@ -1,15 +1,18 @@
-import type { Class, Struct } from "@effect/schema/Schema"
+import type { Struct } from "@effect/schema/Schema"
 import { makeObservable, observable, type CreateObservableOptions } from "mobx"
 import { mapValues } from "remeda"
+import type { Constructor } from "type-fest"
 
 
 export function MobXObservable<
-    C extends Class<any, Struct.Fields, any, any, any, any, any>
+    This extends Constructor<Struct.Type<Struct.Fields>, any> & {
+        readonly fields: { readonly [K in keyof Struct.Fields]: Struct.Fields[K] }
+    }
 >(
-    class_:    C,
+    class_:    This,
     options?:  Omit<CreateObservableOptions, "proxy">,
 ) {
-    return class MobXObservable extends (class_ as Class<any, Struct.Fields, any, any, any, any, any>) {
+    return class MobXObservable extends class_ {
         declare ["constructor"]: typeof MobXObservable
 
         constructor(...args: any[]) {
@@ -20,5 +23,5 @@ export function MobXObservable<
                 options,
             )
         }
-    } as C
+    } as This
 }

src/effect/schema/class/MutableClass.ts

@@ -4,7 +4,7 @@ import type { TMutableClass } from "./TMutableClass"
 import type { HasFields } from "./util"
 
 
-export function MutableClass<Self = never>(identifier: string) {
+export function MutableClass<Self>(identifier: string) {
     return <Fields extends Struct.Fields>(
         fieldsOr:      Fields | HasFields<Fields>,
         annotations?:  Annotations.Schema<Self>,

src/effect/schema/class/TMutableClass.ts

@@ -2,7 +2,7 @@ import type { Annotations, Class, Struct } from "@effect/schema/Schema"
 import type { Mutable } from "effect/Types"
 import type { Constructor } from "type-fest"
 import type { StaticType } from "../../.."
-import type { HasFields, MissingSelfGeneric } from "./util"
+import type { HasFields } from "./util"
 
 
 export type TMutableClass<
@@ -26,12 +26,10 @@ export type TMutableClass<
         StaticType<Class<Self, Fields, I, R, C, Inherited, Proto>>,
         "extend"
     > & {
-        extend<Extended = never>(identifier: string): <newFields extends Struct.Fields>(
+        extend<Extended>(identifier: string): <newFields extends Struct.Fields>(
             fields:        newFields | HasFields<newFields>,
             annotations?:  Annotations.Schema<Extended>,
-        ) => [Extended] extends [never]
+        ) => TMutableClass<
-            ? MissingSelfGeneric<"Base.extend">
-            : TMutableClass<
             Extended,
             Fields & newFields,
             I & Struct.Encoded<newFields>,

src/effect/schema/class/index.ts

@@ -1,3 +1,4 @@
+export { Class } from "./Class"
 export { MobXObservable } from "./MobXObservable"
 export { Mutable } from "./Mutable"
 export { MutableClass } from "./MutableClass"

src/effect/schema/class/tests.ts

@@ -3,22 +3,21 @@ import { MutableClass } from "./MutableClass"
 import { pipe } from "remeda"
 import { Mutable } from "./Mutable"
 import { MobXObservable } from "./MobXObservable"
+import { Class } from "./Class"
 
 
 const UserSuper = <Self>() => pipe(
-    MutableClass<Self>("User")({
+    Class<Self>("User")({
         id: S.BigIntFromSelf,
         role: S.Union(S.Literal("BasicUser"), S.Literal("Admin")),
     }),
 
-    v => MobXObservable(v),
+    Mutable,
+    MobXObservable,
 )
 
 
-class User extends MutableClass<User>("User")({
+class User extends UserSuper<User>() {}
-    id: S.BigIntFromSelf,
-    role: S.Union(S.Literal("BasicUser"), S.Literal("Admin")),
-}) {}
 
 const user1 = new User({ id: 1n, role: "BasicUser" })
 user1.id = 1n

src/effect/schema/class/util.ts

@@ -1,10 +1,6 @@
 import type { Struct } from "@effect/schema/Schema"
 
 
-export type MissingSelfGeneric<Usage extends string, Params extends string = ""> = (
-    `Missing \`Self\` generic - use \`class Self extends ${Usage}<Self>()(${Params}{ ... })\``
-)
-
 export type HasFields<Fields extends Struct.Fields> = (
     | { readonly fields: Fields }
     | { readonly from: HasFields<Fields> }