Talk about setUp and tearDown in the README.

README.md

 `test` provides a standard way of writing and running tests in Dart.
 
 ## Writing Tests
 
 Tests are specified using the top-level [`test()`][test] function, and test
 assertions are made using [`expect()`][expect]:
 
 [test]: http://www.dartdocs.org/documentation/test/latest/index.html#test/test@id_test
 [expect]: http://www.dartdocs.org/documentation/test/latest/index.html#test/test@id_expect
 
@@ skipping 58 matching lines @@
   test(".split() splits the string on the delimiter", () {
     expect("foo,bar,baz", allOf([
       contains("foo"),
       isNot(startsWith("bar")),
       endsWith("baz")
     ]));
   });
 }
 ```
 
+You can use the [`setUp()`][setUp] and [`tearDown()`][tearDown] functions to
+share code between tests. The `setUp()` callback will run before every test in a
+group or test suite, and `tearDown()` will run after. `tearDown()` will run even
+if a test fails, to ensure that it has a chance to clean up after itself.
+
+```dart
+import "package:test/test.dart";
+
+void main() {
+  var server;
+  var url;
+  setUp(() async {
+    server = await HttpServer.bind('localhost', 0);
+    url = Uri.parse("http://${server.address.host}:${server.port}");
+  });
+
+  tearDown(() async {
+    await server.close(force: true);
+    server = null;
+    url = null;
+  });
+
+  // ...
+}
+```
+
+[setUp]: http://www.dartdocs.org/documentation/test/latest/index.html#test/test@id_setUp
+[tearDown]: http://www.dartdocs.org/documentation/test/latest/index.html#test/test@id_tearDown
+
 ## Running Tests
 
 A single test file can be run just using `pub run test:test path/to/test.dart`
 (on Dart 1.10, this can be shortened to `pub run test path/to/test.dart`).
 
 ![Single file being run via pub run"](https://raw.githubusercontent.com/dart-lang/test/master/image/test1.gif)
 
 Many tests can be run at a time using `pub run test:test path/to/dir`.
 
 ![Directory being run via "pub run".](https://raw.githubusercontent.com/dart-lang/test/master/image/test2.gif)
@@ skipping 397 matching lines @@
 
 In this case, the port is `8081`. In another terminal, pass this port to
 `--pub-serve` and otherwise invoke `pub run test:test` as normal:
 
 ```shell
 $ pub run test:test --pub-serve=8081 -p chrome
 "pub serve" is compiling test/my_app_test.dart...
 "pub serve" is compiling test/utils_test.dart...
 00:00 +42: All tests passed!
 ```