英文原文
Now that we’ve discussed how Google approaches testing, it might be enlightening to learn how we got here. As mentioned previously, Google’s engineers didn’t always embrace the value of automated testing. In fact, until 2005, testing was closer to a curiosity than a disciplined practice. Most of the testing was done manually, if it was done at all. However, from 2005 to 2006, a testing revolution occurred and changed the way we approach software engineering. Its effects continue to reverberate within the company to this day.
英文原文
The experience of the GWS project, which we discussed at the opening of this chapter, acted as a catalyst. It made it clear how powerful automated testing could be. Following the improvements to GWS in 2005, the practices began spreading across the entire company. The tooling was primitive. However, the volunteers, who came to be known as the Testing Grouplet, didn’t let that slow them down.
英文原文
Three key initiatives helped usher automated testing into the company’s consciousness: Orientation Classes, the Test Certified program, and Testing on the Toilet. Each one had influence in a completely different way, and together they reshaped Google’s engineering culture.
英文原文
Even though much of the early engineering staff at Google eschewed testing, the pioneers of automated testing at Google knew that at the rate the company was growing, new engineers would quickly outnumber existing team members. If they could reach all the new hires in the company, it could be an extremely effective avenue for introducing cultural change. Fortunately, there was, and still is, a single choke point that all new engineering hires pass through: orientation.
英文原文
Most of Google’s early orientation program concerned things like medical benefits and how Google Search worked, but starting in 2005 it also began including an hourlong discussion of the value of automated testing.The class covered the various benefits of testing, such as increased productivity, better documentation, and support for refactoring. It also covered how to write a good test. For many Nooglers (new Googlers) at the time, such a class was their first exposure to this material. Most important, all of these ideas were presented as though they were standard practice at the company. The new hires had no idea that they were being used as trojan horses to sneak this idea into their unsuspecting teams.
Google早期的培训项目大多关注医疗福利和Google搜索的工作方式，但从2005年开始，它也开始包括一个小时的讨论自动化测试的价值1。这个类涵盖了测试的各种好处，例如提高生产力、更好的文档和对重构的支持。它还介绍了如何编写一个好的测试。对于当时的许多Google人(新员工)来说，这样的课程是他们第一次接触到这些材料。最重要的是，所有这些想法都被认为是公司的标准实践。这些新员工并不知道他们被当成了特洛伊木马，把这个想法偷偷带进了毫无戒心的团队。
英文原文
As Nooglers joined their teams following orientation, they began writing tests and questioning those on the team who didn’t. Within only a year or two, the population of engineers who had been taught testing outnumbered the pretesting culture engineers. As a result, many new projects started off on the right foot.
英文原文
Testing has now become more widely practiced in the industry, so most new hires arrive with the expectations of automated testing firmly in place. Nonetheless, orientation classes continue to set expectations about testing and connect what Nooglers know about testing outside of Google to the challenges of doing so in our very large and very complex codebase.
测试现在已经在行业中得到了更广泛的实践，所以大多数新员工都带着自动化测试的期望来到这里。尽管如此，面向类仍然对测试抱有期望，并将Nooglers对Google之外的测试的了解与在我们非常庞大和非常复杂的代码库中进行测试的挑战联系起来。
英文原文
Initially, the larger and more complex parts of our codebase appeared resistant to good testing practices. Some projects had such poor code quality that they were almost impossible to test. To give projects a clear path forward, the Testing Grouplet devised a certification program that they called Test Certified. Test Certified aimed to give teams a way to understand the maturity of their testing processes and, more critically, cookbook instructions on how to improve it.
最初，我们的代码库中更大、更复杂的部分似乎对良好的测试实践有所抵触。有些项目的代码质量很差，几乎不可能进行测试。为了给项目一个清晰的前进道路，测试小组设计了一个他们称之为测试认证的认证程序。Test Certified旨在为团队提供一种方法来理解他们的测试过程的成熟度，更重要的是，提供关于如何改进测试过程的烹饪指南。
英文原文
The program was organized into five levels, and each level required some concrete actions to improve the test hygiene on the team. The levels were designed in such a way that each step up could be accomplished within a quarter, which made it a convenient fit for Google’s internal planning cadence.
该计划被组织成五个级别，每个级别需要一些具体的行动来改善团队中的测试卫生。这些关卡的设计是这样的，每个步骤都可以在一个季度内完成，这使得它非常适合Google的内部规划节奏。
英文原文
Test Certified Level 1 covered the basics: set up a continuous build; start tracking code coverage; classify all your tests as small, medium, or large; identify (but don’t necessarily fix) flaky tests; and create a set of fast (not necessarily comprehensive) tests that can be run quickly. Each subsequent level added more challenges like “no releases with broken tests” or “remove all nondeterministic tests.” By Level 5, all tests were automated, fast tests were running before every commit, all nondeterminism had been removed, and every behavior was covered. An internal dashboard applied social pressure by showing the level of every team. It wasn’t long before teams were competing with one another to climb the ladder.
Test Certified Level 1涵盖了基本内容:建立一个持续构建;开始跟踪代码覆盖率;将所有测试分类为小、中、大;确定(但不一定修复)不稳定的测试;并创建一组可以快速运行的快速(不一定是全面的)测试。每一个随后的关卡都增加了更多的挑战，比如“没有带有中断测试的发布”或“移除所有不确定性测试”。到第5级，所有的测试都自动化了，在每次提交之前都运行快速测试，所有的不确定性都被消除了，并且涵盖了所有的行为。内部仪表盘通过显示每个团队的级别来施加社会压力。没过多久，团队就开始互相竞争爬上梯子。
英文原文
By the time the Test Certified program was replaced by an automated approach in 2015 (more on pH later), it had helped more than 1,500 projects improve their testing culture.
到2015年，测试认证程序被自动化方法取代(稍后会详细介绍pH值)，它已经帮助超过1500个项目改善了他们的测试文化。
英文原文
Of all the methods the Testing Grouplet used to try to improve testing at Google, perhaps none was more off-beat than Testing on the Toilet (TotT). The goal of TotT was fairly simple: actively raise awareness about testing across the entire company. The question is, what’s the best way to do that in a company with employees scattered around the world?
英文原文
The Testing Grouplet considered the idea of a regular email newsletter, but given the heavy volume of email everyone deals with at Google, it was likely to become lost in the noise. After a little bit of brainstorming, someone proposed the idea of posting flyers in the restroom stalls as a joke. We quickly recognized the genius in it: the bathroom is one place that everyone must visit at least once each day, no matter what. Joke or not, the idea was cheap enough to implement that it had to be tried.
英文原文
In April 2006, a short writeup covering how to improve testing in Python appeared in restroom stalls across Google. This first episode was posted by a small band of volunteers. To say the reaction was polarized is an understatement; some saw it as an invasion of personal space, and they objected strongly. Mailing lists lit up with complaints, but the TotT creators were content: the people complaining were still talking about testing.
英文原文
Ultimately, the uproar subsided and TotT quickly became a staple of Google culture. To date, engineers from across the company have produced several hundred episodes, covering almost every aspect of testing imaginable (in addition to a variety of other technical topics). New episodes are eagerly anticipated and some engineers even volunteer to post the episodes around their own buildings. We intentionally limit each episode to exactly one page, challenging authors to focus on the most important and actionable advice. A good episode contains something an engineer can take back to the desk immediately and try.
英文原文
Ironically for a publication that appears in one of the more private locations, TotT has had an outsized public impact. Most external visitors see an episode at some point in their visit, and such encounters often lead to funny conversations about how Googlers always seem to be thinking about code. Additionally, TotT episodes make great blog posts, something the original TotT authors recognized early on. They began publishing lightly edited versions publicly, helping to share our experience with the industry at large.
英文原文
Despite starting as a joke, TotT has had the longest run and the most profound impact of any of the testing initiatives started by the Testing Grouplet.
英文原文
Testing culture at Google today has come a long way from 2005. Nooglers still attend orientation classes on testing, and TotT continues to be distributed almost weekly. However, the expectations of testing have more deeply embedded themselves in the daily developer workflow.
英文原文
Every code change at Google is required to go through code review. And every change is expected to include both the feature code and tests. Reviewers are expected to review the quality and correctness of both. In fact, it is perfectly reasonable to block a change if it is missing tests.
英文原文
As a replacement for Test Certified, one of our engineering productivity teams recently launched a tool called Project Health (pH). The pH tool continuously gathers dozens of metrics on the health of a project, including test coverage and test latency, and makes them available internally. pH is measured on a scale of one (worst) to five (best). A pH-1 project is seen as a problem for the team to address. Almost every team that runs a continuous build automatically gets a pH score.
英文原文
Over time, testing has become an integral part of Google’s engineering culture. We have myriad ways to reinforce its value to engineers across the company. Through a combination of training, gentle nudges, mentorship, and, yes, even a little friendly competition, we have created the clear expectation that testing is everyone’s job.
英文原文
Why didn’t we start by mandating the writing of tests?
英文原文
The Testing Grouplet had considered asking for a testing mandate from senior leadership but quickly decided against it. Any mandate on how to develop code would be seriously counter to Google culture and likely slow the progress, independent of the idea being mandated. The belief was that successful ideas would spread, so the focus became demonstrating success.
英文原文
If engineers were deciding to write tests on their own, it meant that they had fully accepted the idea and were likely to keep doing the right thing—even if no one was compelling them to.
Footnotes
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This class was so successful that an updated version is still taught today. In fact, it is one of the longestrunning orientation classes in the company’s history. ↩