fixes typing

dependency-manager.ts

@@ -1,6 +1,8 @@
 type Provider<T> = (manager: DependencyManager) => Promise<T> | T;
 
-type ClassType<T> = new () => T;
+type HasConstructor<T> = T extends new (...args: any[]) => unknown ? T : never;
+type ConstructorInstance<T> = T extends new (...args: any[]) => infer I ? I
+  : never;
 
 // deno-lint-ignore no-explicit-any
 type ModuleIdentifier = any;
@@ -41,7 +43,9 @@ export class DependencyManager {
    *
    * @param identifier the identifier used to register the provider
    */
-  async resolve<T>(identifier: ClassType<T>): Promise<T>;
+  async resolve<T>(
+    identifier: HasConstructor<T>,
+  ): Promise<ConstructorInstance<T>>;
   async resolve<T>(identifier: ModuleIdentifier): Promise<T>;
   async resolve(identifier: ModuleIdentifier) {
     const module = this.modules.get(identifier);

readme.md

@@ -53,19 +53,9 @@ Any valid `Map` key can be used as identifier, but using a class allow the retur
 ```typescript
 class MyDependency {}
 
-manager.register(MyDependency, () => new MyDependency());
 const a = await manager.resolve(MyDependecy); //< `a` is of type `MyDependency`
-```
-
-Otherwise you can provide the type as type argument:
-
-```typescript
-function provider() {
-  return 'foo'
-}
-manager.register('my-dependency-identifier', provider);
-const a = await manager.resolve('my-dependency-identifier'); //< `a` is of type `unknown`
-const b = await manager.resolve<string>('my-dependency-identifier'); //< `b` is of type `string`
+const b = await manager.resolve('dependency-identifier'); //< `b` is of type `unknown`
+const c = await manager.resolve<number>('dependency-identifier'); //< `c` is of type `number`
 ```
 
 ## Errors