Answer:9 added wrap function pipe

apps/angular/9-wrap-function-pipe/src/app/app.component.ts

@@ -1,11 +1,13 @@
 import { Component } from '@angular/core';
+import { WrapFunctionPipe } from './wrap-fn.pipe';
 
 @Component({
   selector: 'app-root',
+  imports: [WrapFunctionPipe],
   template: `
     @for (person of persons; track person.name) {
-      {{ showName(person.name, $index) }}
-      {{ isAllowed(person.age, $first) }}
+      {{ showName | wrapFn: person.name : $index }}
+      {{ isAllowed | wrapFn: person.age : $first }}
     }
   `,
 })

apps/angular/9-wrap-function-pipe/src/app/wrap-fn.pipe.ts

@@ -0,0 +1,15 @@
+import { Pipe } from '@angular/core';
+
+@Pipe({
+  name: 'wrapFn',
+  standalone: true,
+  pure: true,
+})
+export class WrapFunctionPipe {
+  transform<T extends (...args: any[]) => any>(
+    fn: T,
+    ...args: Parameters<T>
+  ): ReturnType<T> {
+    return fn(...args);
+  }
+}