From 3d091100d800e81b76adf4851e83b4a0995b3182 Mon Sep 17 00:00:00 2001 From: kokialoves <498497353@qq.com> Date: Tue, 10 Jan 2017 12:31:43 +0800 Subject: [PATCH] 20161227 The Dos and Donts of Writing Test cases in Android.md (#4901) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * Delete 20161227 The Dos and Donts of Writing Test cases in Android.md * Create 20161227 The Dos and Donts of Writing Test cases in Android.md --- ... Donts of Writing Test cases in Android.md | 67 ------- ... Donts of Writing Test cases in Android.md | 170 ++++++++++++++++++ 2 files changed, 170 insertions(+), 67 deletions(-) delete mode 100644 sources/tech/20161227 The Dos and Donts of Writing Test cases in Android.md create mode 100644 translated/tech/20161227 The Dos and Donts of Writing Test cases in Android.md diff --git a/sources/tech/20161227 The Dos and Donts of Writing Test cases in Android.md b/sources/tech/20161227 The Dos and Donts of Writing Test cases in Android.md deleted file mode 100644 index b0741dc920..0000000000 --- a/sources/tech/20161227 The Dos and Donts of Writing Test cases in Android.md +++ /dev/null @@ -1,67 +0,0 @@ -translating by kokialoves -The Do’s and Don’ts of Writing Test cases in Android. -============================================================ - -In this post, I will try to explain the best practices of writing the test cases based on my experience. I will use Espresso code in this post, but these practices will apply on both unit and instrumentation tests. For the purpose of explaining, I will consider a news application. - -> The features and conditions of the application mentioned below are purely fictitious and are meant purely for the purpose of explaining the best practices and have no resemblance to any application active or removed from Play Store. :P - -The news application will have the following activities. - -* LanguageSelection- When the user launches the application for the very first time, he has to select at least one language. On selecting one or more than one language, the selection will be saved in the shared preferences and the user will be redirected to NewsList activity. -* NewsList - When the user lands on the NewsList activity, a request is sent to the server along with the language parameter and the response is shown in the recycler view (which has id _news_list_). In case the language is not present in the shared preference or server does not give a successful response, an error screen will become visible to the user and the recycler view will be gone. The NewsList activity has a button which has the text “Change your Language” if the user had selected only one language and “Change your Languages” if the user had selected more than one language which will always be visible. ( I swear to God that this is a fictional app) -* NewsDetail- As the name suggests, this activity is launched when the user clicks on any news list item. - - -Enough about the great features of the app. Let’s dive into the test cases written for NewsList activity. This is the code which I wrote the very first time. - - -#### Decide carefully what the test case is about. - -In the first test case_ testClickOnAnyNewsItem()_, if the server does not send a successful response, the test case will fail because the visibility of the recycler view is GONE. But that is not what the test case is about. For this test case to PASS or FAIL, the minimum requirement is that the recycler view should be present and if due to any reason, it is not present, then the test case should not be considered FAILED. The correct code for this test should be something like this. - - -#### A test case should be complete in itself - -When I started testing, I always tested the activities in the following sequence - -* LanguageSelection -* NewsList -* NewsDetail - -Since I tested the LanguageSelection activity first, a language was always getting set before the tests for NewsList activity began. But when I tested NewsList activity first, the tests started to fail. The reason for the failure was simple- language was not selected and because of that, the recycler view was not present. Thus, the order of execution of the test cases should not affect the outcome of the test. Therefore before running the test, the language should be saved in the shared preferences. In this case, the test case now becomes independent from LanguageSelection activity test. - - -#### Avoid conditional coding in test cases. - -Now in the second test case _testChangeLanguageFeature()_, we get the count of the languages selected by the user and based on the count, we write an if-else condition for testing. But the if-else conditions should be written inside your actual code, not in the testing code. Each and every condition should be tested separately. So, in this case, instead of writing only a single test case, we should have written two test cases as follows. - - -#### The Test cases should be independent of external factors - -In most of the applications, we interact with external agents like network and database. A test case can invoke a request to the server during its execution and the response can be either successful or failed. But due to the failed response from the server, the test case should not be considered failed. Think of it as this way- If a test case fails, then we make some changes in the client code so that the test code works. But in this case, are we going to make any changes in the client code?- NO. - -But you should also not completely avoid testing the network request and response. Since the server is an external agent, there can be a scenario when it can send some wrong response which might result in crashing of the application. Therefore, you should write test cases and cover all the possible responses from the server, even the responses which the server will never send. In this way, all the code will be covered and you make sure that the application handles all the responses gracefully and never crashes down. - -> Writing the test cases in a correct way is as important as writing the code for which the tests are written. - - -Thanks for reading the article. I hope it helps you write better test cases. You can connect with me on [LinkedIn][1]. You can check out my other medium articles [here][2]. - -_For more about programming, follow _[_Mindorks_][3]_ , so you’ll get notified when we write new posts._ - - --------------------------------------------------------------------------------- - -via: https://blog.mindorks.com/the-dos-and-don-ts-of-writing-test-cases-in-android-70f1b5dab3e1#.lfilq9k5e - -作者：[Anshul Jain][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://blog.mindorks.com/@anshuljain?source=post_header_lockup -[1]:http://www.linkedin.com/in/anshul-jain-b7082573 -[2]:https://medium.com/@anshuljain -[3]:https://blog.mindorks.com/ diff --git a/translated/tech/20161227 The Dos and Donts of Writing Test cases in Android.md b/translated/tech/20161227 The Dos and Donts of Writing Test cases in Android.md new file mode 100644 index 0000000000..ae26094e16 --- /dev/null +++ b/translated/tech/20161227 The Dos and Donts of Writing Test cases in Android.md @@ -0,0 +1,170 @@ +编写android测试单元应该做的和不应该做的. +============================================================ + +在本文中, 根据我的实际经验我将为大家阐述一个测试用例.在本文中我将使用Espresso编码, 但是它们可以用到单元测试当中. 基于以上目的, 我们来研究一个新闻程序. + +> 以下内容纯属虚构,如有雷同纯属巧合:P + +一个新闻APP应该会有以下几个工作流. + + +* 语言选择页面- 当用户第一次打开软件, 他必须至少选择一种语言. 当选择一个或者多个语言, 用shared preferences保存选项,用户跳转到新闻列表页面. +* 新闻列表页面- 当用户来到新闻列表页面, 将发送一个包含语言参数的请求到服务器，并将服务器返回的内容显示在recycler view上(包含有新闻列表的 id?_news_list_). 如果语言参数不存在在shared preferences或者服务器没有返回一个成功消息, 就会弹出一个错误对话框并且recycler view将不可见. 新闻列表页面有个名叫 “Change your Language” 的按钮,如果用户选择了一种语言 或者用户选择多种语言“Change your Languages” 永远是可见的. ( 我对天发誓这是一个虚构的APP软件) +* 新闻详细内容-如同名字所述, 当用户点选新闻列表项将启动这个页面. + + +这个APP已经研究的足够了,让我们深入新闻列表页面编写测试用例. 这是我第一次写的代码. + + +``` +/* + Click on the first news item. + It should open NewsDetailActivity + */ + @Test + public void testClickOnAnyNewsItem() { + onView(allOf(withId(R.id.news_list), isDisplayed())).perform(RecyclerViewActions + .actionOnItemAtPosition(1, click())); + intended(hasComponent(NewsDetailsActivity.class.getName())); + } + + + /** + * To test the correct text on the button + */ + @Test + public void testChangeLanguageFeature() { + int count = UserPreferenceUtil.getSelectedLanguagesCount(); + if (count == 1) { + onView(withText("Choose your Language")).check(matches(isDisplayed())); + } else if (count > 1) { + onView(withText("Choose your Languages")).check(matches(isDisplayed())); + } + ?} +``` +#### 仔细想想测试什么. + +我们首先来测试新闻列表项的点击_?testClickOnAnyNewsItem()_, 如果服务器没有返回成功信息, 测试用例将会返回失败,因为recycler view是不可见的. 但是这个测试用例的通过或者失败并不是我们所期望的结果, 它要求不管什么原因recycler view都是可见的, 如果recycler view不可见,将返回失败信息. 正确的测试代码应该像下面这个样子. + +``` + /* + Click on any news item. + It should open NewsDetailActivity + */ + @Test + public void testClickOnAnyNewsItem() { + try { + /*To test this case, we need to have recyclerView present. If we don't have the + recyclerview present either due to the presence of error_screen, then we should consider + this test case successful. The test case should be unsuccesful only when we click on a + news item and it doesn't open NewsDetail activity + */ + ViewInteraction viewInteraction = onView(withId(R.id.news_list)); + viewInteraction.check(matches(isDisplayed())); + } catch (NoMatchingViewException e) { + return; + } catch (AssertionFailedError e) { + return; + } + //Here we are sure, that the news_list recyclerview is visible to the user. + onView(allOf(withId(R.id.news_list), isDisplayed())).perform(RecyclerViewActions + .actionOnItemAtPosition(1, click())); + intended(hasComponent(NewsDetailsActivity.class.getName())); + } +} + +``` +#### 一个测试用例本身应该是完整的 + +当我开始测试, 我通常按如下顺序测试 + +* 语音选择页面 +* 新闻列表页面 +* 新闻详细内容 + +当我开始测试语音选择页面, 总有一种语音已经是选择好了的. 但是当我测试新闻列表页面, 测试用例开始返回错误信息. 原因很简单- 没有选择语音,recycler view讲不会显示出来.因此, 测试用例的执行顺序不能影响测试结果. 因此在运行测试用例之前, 语言选项必须是保存的. 在本例中,测试用例独立与语言选择页面单独运行. + +``` +@Rule + public ActivityTestRule activityTestRule = + new ActivityTestRule(TopicsActivity.class, false, false); + + /* + Click on any news item. + It should open NewsDetailActivity + */ + @Test + public void testClickOnAnyNewsItem() { + UserPreferenceUtil.saveUserPrimaryLanguage("english"); + Intent intent = new Intent(); + activityTestRule.launchActivity(intent); + try { + ViewInteraction viewInteraction = onView(withId(R.id.news_list)); + viewInteraction.check(matches(isDisplayed())); + } catch (NoMatchingViewException e) { + return; + } catch (AssertionFailedError e) { + return; + } + onView(allOf(withId(R.id.news_list), isDisplayed())).perform(RecyclerViewActions + .actionOnItemAtPosition(1, click())); + intended(hasComponent(NewsDetailsActivity.class.getName())); + ?} +``` +#### 在测试用例中避免使用条件代码. + +现在在第二个测试用例_testChangeLanguageFeature()_, 我们获取到用户选择语言个数, 我们写了if-else条件来进行测试 . 但是 if-else 条件应该写在你的代码当中, 不是测试代码里. 每一个条件应该单独测试. 因此, 在本例中, 我们将写如下两个测试用例. + +``` +/** + * To test the correct text on the button when only one language is selected. + */ + @Test + public void testChangeLanguageFeatureForSingeLanguage() { + //Other initializations + UserPreferenceUtil.saveSelectedLanguagesCount(1); + Intent intent = new Intent(); + activityTestRule.launchActivity(intent); + onView(withText("Choose your Language")).check(matches(isDisplayed())); + } + + /** + * To test the correct text on the button when more than one language is selected. + */ + @Test + public void testChangeLanguageFeatureForMultipleLanguages() { + //Other initializations + UserPreferenceUtil.saveSelectedLanguagesCount(5); //Write anything greater than 1. + Intent intent = new Intent(); + activityTestRule.launchActivity(intent); + onView(withText("Choose your Languages")).check(matches(isDisplayed())); + } + +``` +#### 测试用例应该独立于外部因素 + +在大多数APP中, 我们与外部网络或者数据库进行交互.一个测试用例可以向服务器发送一个请求并获取返回信息. 但是当获取失败信息以后, 我们不能认为测试用例没有通过.试想一下如果测试用例没有通过, 然后我们修改客户端代码,测试用例通过. 但是在本文中, 我们有在客户端进行任何更改吗?-没有. + +但是你应该也无法避免要测试网络请求和响应. 由于服务器是一个外部代理, 我们可以设想一个场景,发送一些可能导致程序崩溃的错误请求. 因此, 你写的测试用例应该覆盖所有可能来自服务器的响应,通过这种方式来保证你的代码不会崩溃. + +> 正确的编写测试用例非常重要的. + +感谢你阅读此文章。你可以联系我[LinkedIn][1]. 你还可以阅读我的其他文章[here][2]. + +获取更多资讯请关注?_[_Mindorks_][3]_?, 你将获得我们的最新信息. + + +-------------------------------------------------------------------------------- + +via: https://blog.mindorks.com/the-dos-and-don-ts-of-writing-test-cases-in-android-70f1b5dab3e1#.lfilq9k5e + +作者：[Anshul Jain][a] +译者：[kokialoves](https://github.com/kokialoves) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://blog.mindorks.com/@anshuljain?source=post_header_lockup +[1]:http://www.linkedin.com/in/anshul-jain-b7082573 +[2]:https://medium.com/@anshuljain +[3]:https://blog.mindorks.com/