flutter_flutter/examples/api/test/material/autocomplete/autocomplete.3_test.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';
import 'package:flutter_api_samples/material/autocomplete/autocomplete.3.dart'
    as example;
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets(
    'can search and find options after waiting for fake network delay and debounce delay',
    (WidgetTester tester) async {
      await tester.pumpWidget(const example.AutocompleteExampleApp());

      expect(find.text('aardvark'), findsNothing);
      expect(find.text('bobcat'), findsNothing);
      expect(find.text('chameleon'), findsNothing);

      await tester.enterText(find.byType(TextFormField), 'a');
      await tester.pump(example.fakeAPIDuration);

      // No results yet, need to also wait for the debounce duration.
      expect(find.text('aardvark'), findsNothing);
      expect(find.text('bobcat'), findsNothing);
      expect(find.text('chameleon'), findsNothing);

      await tester.pump(example.debounceDuration);

      expect(find.text('aardvark'), findsOneWidget);
      expect(find.text('bobcat'), findsOneWidget);
      expect(find.text('chameleon'), findsOneWidget);

      await tester.enterText(find.byType(TextFormField), 'aa');
      await tester.pump(example.debounceDuration + example.fakeAPIDuration);

      expect(find.text('aardvark'), findsOneWidget);
      expect(find.text('bobcat'), findsNothing);
      expect(find.text('chameleon'), findsNothing);
    },
  );

  testWidgets('debounce is reset each time a character is entered', (
    WidgetTester tester,
  ) async {
    await tester.pumpWidget(const example.AutocompleteExampleApp());

    await tester.enterText(find.byType(TextFormField), 'c');
    await tester.pump(
      example.debounceDuration - const Duration(milliseconds: 100),
    );

    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);

    await tester.enterText(find.byType(TextFormField), 'ch');
    await tester.pump(
      example.debounceDuration - const Duration(milliseconds: 100),
    );

    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);

    await tester.enterText(find.byType(TextFormField), 'cha');
    await tester.pump(
      example.debounceDuration - const Duration(milliseconds: 100),
    );

    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);

    await tester.enterText(find.byType(TextFormField), 'cham');
    await tester.pump(
      example.debounceDuration - const Duration(milliseconds: 100),
    );

    // Despite the total elapsed time being greater than debounceDuration +
    // fakeAPIDuration, the search has not yet completed, because the debounce
    // was reset each time text input happened.
    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);

    await tester.enterText(find.byType(TextFormField), 'chame');
    await tester.pump(example.debounceDuration + example.fakeAPIDuration);

    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsOneWidget);
  });

  testWidgets('multiple pending requests', (WidgetTester tester) async {
    await tester.pumpWidget(const example.AutocompleteExampleApp());

    await tester.enterText(find.byType(TextFormField), 'a');

    // Wait until the debounce duration has expired, but the request is still
    // pending.
    await tester.pump(example.debounceDuration);

    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);

    await tester.enterText(find.byType(TextFormField), 'aa');

    // Wait until the first request has completed.
    await tester.pump(example.fakeAPIDuration - example.debounceDuration);

    // The results from the first request are thrown away since the query has
    // changed.
    expect(find.text('aardvark'), findsNothing);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);

    // Wait until the second request has completed.
    await tester.pump(example.fakeAPIDuration);

    // The results of the second request are reflected.
    expect(find.text('aardvark'), findsOneWidget);
    expect(find.text('bobcat'), findsNothing);
    expect(find.text('chameleon'), findsNothing);
  });
}