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New setUp/tearDown in Unit Test library

Posted by Seth Ladd

Graham Wheeler, an engineer on the Dart project, announced today:


Our unit tests now support setUp/tearDown functions. To use these you need to put the tests within a group(). Inside the group body, in addition to calling test() you can call setUp() and/or tearDown() with function arguments. The setUp function will be called before each test and tearDown after each test.

Usually you would set these up at the start of the group:

group('foo', () {
  setUp(() {...});
  tearDown(() {...});
  test(description, () {...});
  ...
});

but you can interlace them differently; each test() will use the most recently set values setUp/tearDown.

Whenever a new group is started these are reset. This applies for nested groups too. Nested groups do not inherit these functions or augment them; they get their own. This seemed the most flexible approach as chaining can always be done explicitly.

Another new (unrelated) change is that you can now pass a --filter=<string> argument to test.py. Only tests whose descriptions match the supplied string will be executed. The string gets wrapped in a RegExp so you can use flexible matching. This can be combined with other restrictions, so for example I could use:

tools/test.py --compiler=none --runtime=vm --filter=contains lib/unittest

to run all the tests in lib/unittest/test*.dart that have descriptions containing the word contains.

As always, you can join the Dart mailing list to send along your feedback. Thanks for trying Dart!

Comments

  1. Dart is just a greatly improved version of Java resp. rather GWT. A Java dev would feel much more comfortable in Dart than in JavaScript that has no predefined structure to do anything. In JavaScript either you know all its DOs and DO NOTs or your slightly bigger project is doomed.

    ReplyDelete
  2. Syntax error: test(description, () {...}); should betest('description', () {...});

    ReplyDelete

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