Dart 軌道上的測試

下載練習

使用 Exercism CLI 下載你想做的練習吧。

exercism download --track=dart --exercise=hello-world

接著切換到練習所在的目錄。

cd /path/to/exercism/dart/hello-world

安裝相依套件

執行測試之前，先下載練習的相依套件。

dart pub get

執行測試

dart test

看懂測試結果

dart test預設使用精簡報告器，在一行中顯示通過、略過與失敗測試的即時數量。

$ dart test
00:00 +1 -1: test/binary_search_test.dart: finds a value in the middle of an array [E]
  Expected: <3>
    Actual: <0>

  package:matcher                    expect
  test/binary_search_test.dart 13:5  main.<fn>


To run this test again: dart test test/binary_search_test.dart -p vm --plain-name 'finds a value in the middle of an array'
00:00 +1 ~9 -1: Some tests failed.

• +1代表 1 個測試通過
• ~9代表 9 個測試略過
• -1代表 1 個測試失敗

若想看到每個測試更詳細的輸出，請使用展開報告器，它會在每個測試執行時顯示結果。

$ dart test -r expanded
00:00 +0: loading test/binary_search_test.dart
00:00 +0: test/binary_search_test.dart: finds a value in an array with one element
00:00 +1: test/binary_search_test.dart: finds a value in the middle of an array
00:00 +1 -1: test/binary_search_test.dart: finds a value in the middle of an array [E]
  Expected: <3>
    Actual: <0>
  
  package:matcher                    expect
  test/binary_search_test.dart 13:5  main.<fn>
  
00:00 +1 -1: test/binary_search_test.dart: finds a value at the beginning of an array
00:00 +1 ~1 -1: test/binary_search_test.dart: finds a value at the end of an array
00:00 +1 ~2 -1: test/binary_search_test.dart: finds a value in an array of odd length
00:00 +1 ~3 -1: test/binary_search_test.dart: finds a value in an array of even length
00:00 +1 ~4 -1: test/binary_search_test.dart: identifies that a value is not included in the array
00:00 +1 ~5 -1: test/binary_search_test.dart: a value smaller than the array's smallest value is not found
00:00 +1 ~6 -1: test/binary_search_test.dart: a value larger than the array's largest value is not found
00:00 +1 ~7 -1: test/binary_search_test.dart: nothing is found in an empty array
00:00 +1 ~8 -1: test/binary_search_test.dart: nothing is found when the left and right bounds cross
00:00 +1 ~9 -1: Some tests failed.

逐一完成測試

大多數練習都包含多個測試，預設情況下除了第一個之外，其餘都會被略過。

void main() {
  final twoFer = TwoFer();

  group('TwoFer', () {
    test('no name given', () {
      final result = twoFer.statement();
      expect(result, equals('One for you, one for me.'));
    }, skip: false);

    test('a name given', () {
      final result = twoFer.statement('Alice');
      expect(result, equals('One for Alice, one for me.'));
    }, skip: true);

    test('another name given', () {
      final result = twoFer.statement('Bob');
      expect(result, equals('One for Bob, one for me.'));
    }, skip: true);
  });
}

如果想一次完成一個測試，就隨著進度把每個測試的 skip: true改成 skip: false。 或者，你也可以不修改檔案，直接一次執行所有測試。

dart test --run-skipped

提交時，線上測試執行器會執行所有測試，包括被略過的測試。

處理錯誤「Could not find a command named frontend_server.dart.snapshot」

假設你有一個已經解完並提交的練習，隔了一段時間後又回來看它。 當你測試它時，可能會遇到這個錯誤：

$ dart test
...
Could not find a command named "/path/to/frontend_server.dart.snapshot".

解決方法是刪除 pubspec.lock 檔案，然後再次執行 dart 指令。