tests.rst の原文を追加

Author: gyohk

best_practices/tests.rst

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+Tests
+=====
+
+Roughly speaking, there are two types of test. Unit testing allows you to
+test the input and output of specific functions. Functional testing allows
+you to command a "browser" where you browse to pages on your site, click
+links, fill out forms and assert that you see certain things on the page.
+
+Unit Tests
+----------
+
+Unit tests are used to test your "business logic", which should live in classes
+that are independent of Symfony. For that reason, Symfony doesn't really
+have an opinion on what tools you use for unit testing. However, the most
+popular tools are `PhpUnit`_ and `PhpSpec`_.
+
+Functional Tests
+----------------
+
+Creating really good functional tests can be tough so some developers skip
+these completely. Don't skip the functional tests! By defining some *simple*
+functional tests, you can quickly spot any big errors before you deploy them:
+
+.. best-practice::
+
+    Define a functional test that at least checks if your application pages
+    are successfully loading.
+
+A functional test can be as easy as this:
+
+.. code-block:: php
+
+    /** @dataProvider provideUrls */
+    public function testPageIsSuccessful($url)
+    {
+        $client = self::createClient();
+        $client->request('GET', $url);
+
+        $this->assertTrue($client->getResponse()->isSuccessful());
+    }
+
+    public function provideUrls()
+    {
+        return array(
+            array('/'),
+            array('/posts'),
+            array('/post/fixture-post-1'),
+            array('/blog/category/fixture-category'),
+            array('/archives'),
+            // ...
+        );
+    }
+
+This code checks that all the given URLs load successfully, which means that
+their HTTP response status code is between ``200`` and ``299``. This may
+not look that useful, but given how little effort this took, it's worth
+having it in your application.
+
+In computer software, this kind of test is called `smoke testing`_ and consists
+of *"preliminary testing to reveal simple failures severe enough to reject a
+prospective software release"*.
+
+Hardcode URLs in a Functional Test
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Some of you may be asking why the previous functional test doesn't use the URL
+generator service:
+
+.. best-practice::
+
+    Hardcode the URLs used in the functional tests instead of using the URL
+    generator.
+
+Consider the following functional test that uses the ``router`` service to
+generate the URL of the tested page:
+
+.. code-block:: php
+
+    public function testBlogArchives()
+    {
+        $client = self::createClient();
+        $url = $client->getContainer()->get('router')->generate('blog_archives');
+        $client->request('GET', $url);
+
+        // ...
+    }
+
+This will work, but it has one *huge* drawback. If a developer mistakenly
+changes the path of the ``blog_archives`` route, the test will still pass,
+but the original (old) URL won't work! This means that any bookmarks for
+that URL will be broken and you'll lose any search engine page ranking.
+
+Testing JavaScript Functionality
+--------------------------------
+
+The built-in functional testing client is great, but it can't be used to
+test any JavaScript behavior on your pages. If you need to test this, consider
+using the `Mink`_ library from within PHPUnit.
+
+Of course, if you have a heavy JavaScript frontend, you should consider using
+pure JavaScript-based testing tools.
+
+Learn More about Functional Tests
+---------------------------------
+
+Consider using `Faker`_ and `Alice`_ libraries to generate real-looking data
+for your test fixtures.
+
+.. _`Faker`: https://github.com/fzaninotto/Faker
+.. _`Alice`: https://github.com/nelmio/alice
+.. _`PhpUnit`: https://phpunit.de/
+.. _`PhpSpec`: http://www.phpspec.net/
+.. _`Mink`: http://mink.behat.org
+.. _`smoke testing`: http://en.wikipedia.org/wiki/Smoke_testing_(software)