diff --git a/sources/tech/20210204 How to implement business requirements in software development.md b/sources/tech/20210204 How to implement business requirements in software development.md
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-[#]: collector: (lujun9972)
-[#]: translator: (toknow-gh)
-[#]: reviewer: ( )
-[#]: publisher: ( )
-[#]: url: ( )
-[#]: subject: (How to implement business requirements in software development)
-[#]: via: (https://opensource.com/article/21/2/exceptional-behavior)
-[#]: author: (Alex Bunardzic https://opensource.com/users/alex-bunardzic)
-
-How to implement business requirements in software development
-======
-Increment your e-commerce app to ensure it implements required business
-process rules correctly.
-![Working on a team, busy worklife][1]
-
-In my previous articles in this series, I explained why tackling coding problems all at once, as if they were hordes of zombies, is a mistake. I'm using a helpful acronym to explain why it's better to approach problems incrementally. **ZOMBIES** stands for:
-
-**Z** – Zero
-**O** – One
-**M** – Many (or more complex)
-**B** – Boundary behaviors
-**I** – Interface definition
-**E** – Exercise exceptional behavior
-**S** – Simple scenarios, simple solutions
-
-In the first three articles in this series, I demonstrated the first five **ZOMBIES** principles. The first article [implemented **Z**ero][2], which provides the simplest possible path through your code. The second article performed [tests with **O**ne and **M**any][3] samples, and the third article looked at [**B**oundaries and **I**nterfaces][4]. In this article, I'll take a look at the penultimate letter in our acronym: **E**, which stands for "exercise exceptional behavior."
-
-### Exceptional behavior in action
-
-When you write an app like the e-commerce tool in this example, you need to contact product owners or business sponsors to learn if there are any specific business policy rules that need to be implemented.
-
-Sure enough, as with any e-commerce operation, you want to put business policy rules in place to entice customers to keep buying. Suppose a business policy rule has been communicated that any order with a grand total greater than $500 gets a percentage discount.
-
-OK, time to roll up your sleeves and craft the executable expectation for this business policy rule:
-
-
-```
-[Fact]
-public void Add2ItemsTotal600GrandTotal540() {
-        var expectedGrandTotal = 540.00;
-        var actualGrandTotal = 0.00;
-        Assert.Equal(expectedGrandTotal, actualGrandTotal);
-}
-```
-
-The confirmation example that encodes the business policy rule states that if the order total is $600.00, the `shoppingAPI` will calculate the grand total to discount it to $540.00. The script above fakes the expectation just to see it fail. Now, make it pass:
-
-
-```
-[Fact]
-public void Add2ItemsTotal600GrandTotal540() {
-        var expectedGrandTotal = 540.00;
-        Hashtable item = [new][5] Hashtable();
-        item.Add("00000001", 200.00);
-        shoppingAPI.AddItem(item);
-        Hashtable item2 = [new][5] Hashtable();
-        item2.Add("00000002", 400.00);
-        shoppingAPI.AddItem(item2);
-        var actualGrandTotal = shoppingAPI.CalculateGrandTotal();
-        Assert.Equal(expectedGrandTotal, actualGrandTotal);
-}
-```
-
-In the confirmation example, you are adding one item priced at $200 and another item priced at $400 for a total of $600 for the order. When you call the `CalculateGrandTotal()` method, you expect to get a total of $540.
-
-Will this microtest pass?
-
-
-```
-[xUnit.net 00:00:00.57] tests.UnitTest1.Add2ItemsTotal600GrandTotal540 [FAIL]
-  X tests.UnitTest1.Add2ItemsTotal600GrandTotal540 [2ms]
-  Error Message:
-   Assert.Equal() Failure
-Expected: 540
-Actual: 600
-[...]
-```
-
-Well, it fails miserably. You were expecting $540, but the system calculates $600. Why the error? It's because you haven't taught the system how to calculate the discount on order totals larger than $500 and then subtract that discount from the grand total.
-
-Implement that processing logic. Judging from the confirmation example above, when the order total is $600.00 (which is greater than the business rule threshold of an order totaling $500), the expected grand total is $540. This means the system needs to subtract $60 from the grand total. And $60 is precisely 10% of $600. So the business policy rule that deals with discounts expects a 10% discount on all order totals greater than $500.
-
-Implement this processing logic in the `ShippingAPI` class:
-
-
-```
-private double Calculate10PercentDiscount(double total) {
-        double discount = 0.00;
-        if(total > 500.00) {
-                discount = (total/100) * 10;
-        }
-        return discount;
-}
-```
-
-First, check to see if the order total is greater than $500. If it is, then calculate 10% of the order total.
-
-You also need to teach the system how to subtract the calculated 10% from the order grand total. That's a very straightforward change:
-
-
-```
-`return grandTotal - Calculate10PercentDiscount(grandTotal);`
-```
-
-Now all tests pass, and you're again enjoying steady success. Your script **Exercises exceptional behavior** to implement the required business policy rules.
-
-### One more to go
-
-I've taken us to **ZOMBIE** now, so there's just **S** remaining. I'll cover that in the exciting series finale.
-
---------------------------------------------------------------------------------
-
-via: https://opensource.com/article/21/2/exceptional-behavior
-
-作者：[Alex Bunardzic][a]
-选题：[lujun9972][b]
-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://opensource.com/users/alex-bunardzic
-[b]: https://github.com/lujun9972
-[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/team_dev_email_chat_video_work_wfm_desk_520.png?itok=6YtME4Hj (Working on a team, busy worklife)
-[2]: https://opensource.com/article/21/1/zombies-zero
-[3]: https://opensource.com/article/21/1/zombies-2-one-many
-[4]: https://opensource.com/article/21/1/zombies-3-boundaries-interface
-[5]: http://www.google.com/search?q=new+msdn.microsoft.com
diff --git a/translated/tech/20210204 How to implement business requirements in software development.md b/translated/tech/20210204 How to implement business requirements in software development.md
new file mode 100644
index 0000000000..60ed41b692
--- /dev/null
+++ b/translated/tech/20210204 How to implement business requirements in software development.md	
@@ -0,0 +1,128 @@
+[#]: collector: (lujun9972)
+[#]: translator: (toknow-gh)
+[#]: reviewer: ( )
+[#]: publisher: ( )
+[#]: url: ( )
+[#]: subject: (How to implement business requirements in software development)
+[#]: via: (https://opensource.com/article/21/2/exceptional-behavior)
+[#]: author: (Alex Bunardzic https://opensource.com/users/alex-bunardzic)
+
+ZOMBIES：如何在软件开发中实现业务需求（四）
+======
+完善你的电商 app，使它能够正确处理业务规则。
+![Working on a team, busy worklife][1]
+
+在前面的文章中，我已经解释了为什么将编程问题看作一整群丧尸来处理是错误的。我用 ZOMBIES 方法来解释为什么循序渐进地处理问题更好。
+ZOMBIES 表示以下首字母缩写：
+
+**Z** – 最简场景（Zero）
+**O** – 单元素场景（One）
+**M** – 多元素场景（Many or more complex）
+**B** – 边界行为（Boundary behaviors）
+**I** – 接口定义（Interface definition）
+**E** – 处理特殊行为（Exercise exceptional behavior）
+**S** – 简单场景用简单的解决方案（Simple scenarios, simple solutions）
+
+在系列的前三篇文章中，我展示了 ZOMBIES 方法的前五项。第一篇中 [实现了最简场景][2]，它为代码提供了最简可行路径。第二篇文章中执行了 [单元素场景和多元素场景上的测试][3]。第三篇中介绍了[边界和接口][4]。在本文中，我将带你了解倒数第二个方法：处理特殊行为。
+
+### 处理特殊行为
+
+在开发一个电子购物应用时，你需要从产品负责人或赞助商那里了解需要采用什么销售策略。
+
+毫无疑问，与任何电子商业活动一样，你需要通过制定销售策略来诱导顾客进行消费。假设有如下的销售策略：订单金额超过 ￥500 时可以享受一定的折扣优惠。
+
+现在将这个销售策略转换为可运行期望：
+
+
+```
+[Fact]
+public void Add2ItemsTotal600GrandTotal540() {
+        var expectedGrandTotal = 540.00;
+        var actualGrandTotal = 0.00;
+        Assert.Equal(expectedGrandTotal, actualGrandTotal);
+}
+```
+
+这个正面样例表示的销售策略是，如果订单总额为 ￥600.00，那么 `shoppingAPI` 会将其减价为 ￥540.00。上面的代码伪造了一个失败验证用例。现在修改它，让它能够通过测试：
+
+
+```
+[Fact]
+public void Add2ItemsTotal600GrandTotal540() {
+        var expectedGrandTotal = 540.00;
+        Hashtable item = [new][5] Hashtable();
+        item.Add("00000001", 200.00);
+        shoppingAPI.AddItem(item);
+        Hashtable item2 = [new][5] Hashtable();
+        item2.Add("00000002", 400.00);
+        shoppingAPI.AddItem(item2);
+        var actualGrandTotal = shoppingAPI.CalculateGrandTotal();
+        Assert.Equal(expectedGrandTotal, actualGrandTotal);
+}
+```
+
+在这个正样例中，你向购物框加入一件价值 ￥200 的商品和一件价值 ￥400 的商品，使总价达到 ￥600 。当调用 `CalculateGrandTotal()` 方法时，你期望总价是 ￥540。
+
+这个微测试能够通过吗？
+
+
+```
+[xUnit.net 00:00:00.57] tests.UnitTest1.Add2ItemsTotal600GrandTotal540 [FAIL]
+  X tests.UnitTest1.Add2ItemsTotal600GrandTotal540 [2ms]
+  Error Message:
+   Assert.Equal() Failure
+Expected: 540
+Actual: 600
+[...]
+```
+
+很可惜，它失败了。你期望的结果是 ￥540，但计算结果为 ￥600。为什么会这样呢？那是因为你还没有告诉系统在订单总价大于 ￥500 时怎么进行折扣计算。
+
+现在来实现折扣计算逻辑。根据上面的正样例可知，当订单总价为 ￥600（超过了营销策略的阈值 ￥500）时，期望的最终总价为 ￥540。也就是说系统需要从订单总额中减去 ￥60。刚好是是原订单总价的 10%。因此该销售规则就是当订单总额超过 ￥500 时享受九折优惠。
+
+在 `ShippingAPI` 类中实现该处理逻辑：
+
+
+```
+private double Calculate10PercentDiscount(double total) {
+        double discount = 0.00;
+        if(total > 500.00) {
+                discount = (total/100) * 10;
+        }
+        return discount;
+}
+```
+
+首先，检查订单总额是否大于 ￥500 。如果是，则计算出总额的 10%。
+
+你还需要告诉系统怎么从订单总额中减去 10%。改动非常直接：
+
+
+```
+`return grandTotal - Calculate10PercentDiscount(grandTotal);`
+```
+
+到此，所有测试都能够通过。你又一次享受到系统处于稳态的欢愉。你的代码通过处理特殊行为实现了需要的销售策略。
+
+### 最后一步
+现在我已经介绍完 ZOMBIE 了，只剩下 S 了。我将会在最后一篇中介绍它。
+
+
+--------------------------------------------------------------------------------
+
+via: https://opensource.com/article/21/2/exceptional-behavior
+
+作者：[Alex Bunardzic][a]
+选题：[lujun9972][b]
+译者：[toknow-gh](https://github.com/toknow-gh)
+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://opensource.com/users/alex-bunardzic
+[b]: https://github.com/lujun9972
+[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/team_dev_email_chat_video_work_wfm_desk_520.png?itok=6YtME4Hj (Working on a team, busy worklife)
+[2]: https://opensource.com/article/21/1/zombies-zero
+[3]: https://opensource.com/article/21/1/zombies-2-one-many
+[4]: https://opensource.com/article/21/1/zombies-3-boundaries-interface
+[5]: http://www.google.com/search?q=new+msdn.microsoft.com