feat(challenge): add a pipe challenge serie

apps/pipe-hard/src/app/app.component.ts

@@ -0,0 +1,36 @@
+import { NgFor } from '@angular/common';
+import { Component } from '@angular/core';
+import { PersonUtils } from './person.utils';
+
+@Component({
+  standalone: true,
+  imports: [NgFor],
+  selector: 'app-root',
+  template: `
+    <div *ngFor="let activity of activities">
+      {{ activity.name }} :
+      <div
+        *ngFor="let person of persons; let index = index; let isFirst = first">
+        {{ showName(person.name, index) }}
+        {{ isAllowed(person.age, isFirst, activity.minimumAge) }}
+      </div>
+    </div>
+  `,
+})
+export class AppComponent {
+  persons = [
+    { name: 'Toto', age: 10 },
+    { name: 'Jack', age: 15 },
+    { name: 'John', age: 30 },
+  ];
+
+  activities = [
+    { name: 'biking', minimumAge: 12 },
+    { name: 'hiking', minimumAge: 25 },
+    { name: 'dancing', minimumAge: 1 },
+  ];
+
+  showName = PersonUtils.showName;
+
+  isAllowed = PersonUtils.isAllowed;
+}

apps/pipe-hard/src/app/person.utils.ts

@@ -0,0 +1,17 @@
+const showName = (name: string, index: number) => {
+  // very heavy computation
+  return `${name} - ${index}`;
+};
+
+const isAllowed = (age: number, isFirst: boolean, activityAge: number) => {
+  if (isFirst) {
+    return 'always allowed';
+  } else {
+    return age > activityAge ? 'allowed' : 'declined';
+  }
+};
+
+export const PersonUtils = {
+  showName,
+  isAllowed,
+};