Made the validate function of the ContraintStrategy in the typescript… (

#324)

* Made the validate function of the ContraintStrategy in the typescript definition optional (as it is also optional in the js-code) added the validate function in the readme doc

* removed the no-op validate function as it is now correctly optional in the ts-typings

---------

Co-authored-by: Nick <nick@bit4bit.at>

README.md

@@ -730,7 +730,10 @@ const customVersioning = {
   deriveConstraint: (req, ctx) => {
     return req.headers['accept']
   },
-  mustMatchWhenDerived: true // if the request is asking for a version, don't match un-version-constrained handlers
+  mustMatchWhenDerived: true, // if the request is asking for a version, don't match un-version-constrained handlers
+  validate (value) {  // optional validate function, validates the assigned value at route-configuration (the .on function) time (not the runtime-value)
+    assert(typeof value === 'string', 'Version should be a string')
+  }
 }
 
 const router = FindMyWay({ constraints: { version: customVersioning } });

index.d.ts

@@ -67,7 +67,7 @@ declare namespace Router {
       del?(value: T) : void,
       empty?() : void
     },
-    validate(value: unknown): void,
+    validate?(value: unknown): void,
     deriveConstraint<Context>(req: Req<V>, ctx?: Context) : T,
   }
 

test/types/router.test-d.ts

@@ -154,7 +154,6 @@ let http2Res!: Http2ServerResponse;
     deriveConstraint<Context>(req: Router.Req<Router.HTTPVersion.V1>, ctx: Context | undefined): string {
       return req.headers.accept ?? ''
     },
-    validate(value: unknown): void {},
     storage () {
       return {
         get (version) { return handler },