pkgs/test_api/test/frontend/matcher/prints_test.dart

// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:async';

import 'package:test_api/src/utils.dart';
import 'package:test/test.dart';

import '../../utils.dart';

void main() {
  group('synchronous', () {
    test('passes with an expected print', () {
      expect(() => print('Hello, world!'), prints('Hello, world!\n'));
    });

    test('combines multiple prints', () {
      expect(() {
        print('Hello');
        print('World!');
      }, prints('Hello\nWorld!\n'));
    });

    test('works with a Matcher', () {
      expect(() => print('Hello, world!'), prints(contains('Hello')));
    });

    test('describes a failure nicely', () async {
      var closure = () => print('Hello, world!');
      var liveTest = await runTestBody(() {
        expect(closure, prints('Goodbye, world!\n'));
      });

      expectTestFailed(
          liveTest,
          allOf([
            startsWith("Expected: prints 'Goodbye, world!\\n'\n"
                "            ''\n"
                '  Actual: <'),
            endsWith('>\n'
                "   Which: printed 'Hello, world!\\n'\n"
                "                    ''\n"
                '            which is different.\n'
                '                  Expected: Goodbye, w ...\n'
                '                    Actual: Hello, wor ...\n'
                '                            ^\n'
                '                   Differ at offset 0\n')
          ]));
    });

    test('describes a failure with a non-descriptive Matcher nicely', () async {
      var closure = () => print('Hello, world!');
      var liveTest = await runTestBody(() {
        expect(closure, prints(contains('Goodbye')));
      });

      expectTestFailed(
          liveTest,
          allOf([
            startsWith("Expected: prints contains 'Goodbye'\n"
                '  Actual: <'),
            endsWith('>\n'
                "   Which: printed 'Hello, world!\\n'\n"
                "                    ''\n")
          ]));
    });

    test('describes a failure with no text nicely', () async {
      var closure = () {};
      var liveTest = await runTestBody(() {
        expect(closure, prints(contains('Goodbye')));
      });

      expectTestFailed(
          liveTest,
          allOf([
            startsWith("Expected: prints contains 'Goodbye'\n"
                '  Actual: <'),
            endsWith('>\n'
                '   Which: printed nothing\n')
          ]));
    });

    test('with a non-function', () async {
      var liveTest = await runTestBody(() {
        expect(10, prints(contains('Goodbye')));
      });

      expectTestFailed(
          liveTest,
          "Expected: prints contains 'Goodbye'\n"
          '  Actual: <10>\n'
          '   Which: was not a unary Function\n');
    });
  });

  group('asynchronous', () {
    test('passes with an expected print', () {
      expect(() => Future(() => print('Hello, world!')),
          prints('Hello, world!\n'));
    });

    test('combines multiple prints', () {
      expect(
          () => Future(() {
                print('Hello');
                print('World!');
              }),
          prints('Hello\nWorld!\n'));
    });

    test('works with a Matcher', () {
      expect(() => Future(() => print('Hello, world!')),
          prints(contains('Hello')));
    });

    test('describes a failure nicely', () async {
      var closure = () => Future(() => print('Hello, world!'));
      var liveTest = await runTestBody(() {
        expect(closure, prints('Goodbye, world!\n'));
      });

      expectTestFailed(
          liveTest,
          allOf([
            startsWith("Expected: prints 'Goodbye, world!\\n'\n"
                "            ''\n"
                '  Actual: <'),
            contains('>\n'
                "   Which: printed 'Hello, world!\\n'\n"
                "                    ''\n"
                '            which is different.\n'
                '                  Expected: Goodbye, w ...\n'
                '                    Actual: Hello, wor ...\n'
                '                            ^\n'
                '                   Differ at offset 0')
          ]));
    });

    test('describes a failure with a non-descriptive Matcher nicely', () async {
      var closure = () => Future(() => print('Hello, world!'));
      var liveTest = await runTestBody(() {
        expect(closure, prints(contains('Goodbye')));
      });

      expectTestFailed(
          liveTest,
          allOf([
            startsWith("Expected: prints contains 'Goodbye'\n"
                '  Actual: <'),
            contains('>\n'
                "   Which: printed 'Hello, world!\\n'\n"
                "                    ''")
          ]));
    });

    test('describes a failure with no text nicely', () async {
      var closure = () => Future.value();
      var liveTest = await runTestBody(() {
        expect(closure, prints(contains('Goodbye')));
      });

      expectTestFailed(
          liveTest,
          allOf([
            startsWith("Expected: prints contains 'Goodbye'\n"
                '  Actual: <'),
            contains('>\n'
                '   Which: printed nothing')
          ]));
    });

    test("won't let the test end until the Future completes", () {
      return expectTestBlocks(() {
        var completer = Completer();
        expect(() => completer.future, prints(isEmpty));
        return completer;
      }, (completer) => completer.complete());
    });

    test("blocks expectLater's Future", () async {
      var completer = Completer();
      var fired = false;

      unawaited(expectLater(() {
        scheduleMicrotask(() => print('hello!'));
        return completer.future;
      }, prints('hello!\n'))
          .then((_) {
        fired = true;
      }));

      await pumpEventQueue();
      expect(fired, isFalse);

      completer.complete();
      await pumpEventQueue();
      expect(fired, isTrue);
    });
  });
}