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src/core/compose.spec.ts

@@ -18,16 +18,20 @@ it('should execute middleware handlers in order', async () => {
       order.push(middleware1);
       return handler(...args);
     };
+  middleware1['meta'] = {1: '1'};
   const middleware2 =
     (handler) =>
     (...args) => {
       order.push(middleware2);
       return handler(...args);
     };
+  middleware2['meta'] = {2: '2'};
 
-  compose(middleware1, middleware2)(async () => {})({});
+  const composedHandler = compose(middleware1, middleware2)(async () => {});
+  composedHandler({});
 
   expect(order).toEqual([middleware1, middleware2]);
+  expect(composedHandler['meta']).toEqual({1: '1', 2: '2'});
 });
 
 it('should provide actual handler reference via "actual" property', async () => {

src/core/compose.ts

@@ -293,5 +293,5 @@ export function compose<E1, E2, E3, R1, R2, R3>(
 // -> Anyway: This should be fixed in the future
 export function compose<E1, E2, R1, R2>(f: Middleware<E1, E2, R1, R2>): Middleware<E1, E2, R1, R2>;
 export function compose(...fns) {
-  return fns.reduce((f, g) => (handler) => Object.assign(f(g(handler)), { actual: handler }));
+  return fns.reduce((f, g) => (handler) => Object.assign(f(g(handler)), { actual: handler, meta: {...f.meta, ...g.meta} }));
 }