test: add issue 106

Closes #106

Author: timdeschryver

src/app/issues/issue-106.spec.ts

@@ -0,0 +1,32 @@
+import { Component } from '@angular/core';
+import { BehaviorSubject } from 'rxjs';
+import { tap } from 'rxjs/operators';
+import { render, screen, fireEvent, waitFor } from '@testing-library/angular';
+
+@Component({
+  template: `<button (click)="toggleShow()" data-testid="toggle">toggle</button>
+    <div *ngIf="show$ | async" data-testid="getme">Here I am</div>`,
+})
+export class TestSelectComponent {
+  showSubj = new BehaviorSubject(false);
+  show$ = this.showSubj.asObservable();
+
+  toggleShow() {
+    this.showSubj.next(true);
+  }
+}
+
+it('should show hidden text', async () => {
+  await render(TestSelectComponent);
+  const toggle = screen.getByTestId('toggle');
+  const hiddenText = screen.queryByTestId('getme');
+
+  expect(hiddenText).toBeNull();
+  fireEvent.click(toggle);
+
+  // fails
+  // await waitFor(() => expect(hiddenText).not.toBeNull());
+
+  // succeeds
+  await waitFor(() => expect(screen.queryByTestId('getme')).not.toBeNull());
+});