refactor: extract reserved providers

src/container.ts

@@ -3,7 +3,15 @@ import {assert, ErrorMessage, expectNever} from "./errors";
 import type {Injection, Injections} from "./injection";
 import {useInjectionContext, withInjectionContext} from "./injection-context";
 import {getMetadata} from "./metadata";
-import {type InjectionProvider, isClassProvider, isFactoryProvider, isProvider, isValueProvider} from "./provider";
+import {
+  type InjectionProvider,
+  isClassProvider,
+  isFactoryProvider,
+  isProvider,
+  isValueProvider,
+  NullProvider,
+  UndefinedProvider,
+} from "./provider";
 import {InjectionScope} from "./scope";
 import {type Constructor, type InjectionToken, isConstructor, Type} from "./token";
 import {Stack} from "./utils/stack";
@@ -20,8 +28,8 @@ export interface ContainerOptions {
 export class Container {
   #reservedRegistry = new ProviderRegistry([
     [Type.Any, null!],
-    [Type.Null, {token: Type.Null, useValue: null}],
-    [Type.Undefined, {token: Type.Undefined, useValue: undefined}],
+    [Type.Null, NullProvider],
+    [Type.Undefined, UndefinedProvider],
   ]);
 
   #providerRegistry = new ProviderRegistry();
@@ -160,7 +168,6 @@ export class Container {
       if (provider) {
         return provider;
       }
-      return this.parent?.resolveProvider(token);
     }
   }
 

src/metadata.ts

@@ -9,7 +9,7 @@ export interface InjectionMetadata<This extends object = any> {
   tokens: InjectionToken<This>[];
 }
 
-class InjectionMetadataRegistry {
+export class InjectionMetadataRegistry {
   #map = new WeakMap<DecoratorMetadata, InjectionMetadata>();
 
   get<T extends object>(key: DecoratorMetadata): InjectionMetadata<T> | undefined {

src/provider.ts

@@ -41,6 +41,18 @@ export function defineProvider<Value>(provider: InjectionProvider<Value>): Injec
   return provider;
 }
 
+// @internal
+export const NullProvider = defineProvider({
+  token: Type.Null,
+  useValue: null,
+});
+
+// @internal
+export const UndefinedProvider = defineProvider({
+  token: Type.Undefined,
+  useValue: undefined,
+});
+
 // @internal
 export function isProvider<T>(injection: Injection<T>) {
   return (