有没有办法向ReSharper表明由于按合同设计需要检查,不会出现空引用?例如,以下代码将在第7行和第8行的ReSharper中引发警告(Possible 'null' assignment to entity marked with 'NotNull' attribute
):
private Dictionary<string, string> _Lookup = new Dictionary<string, string>();
public void Foo(string s)
{
Contract.Requires(!String.IsNullOrEmpty(s));
if (_Lookup.ContainsKey(s))
_Lookup.Remove(s);
}
真正奇怪的是,如果删除Contract.Requires(...)
行,ReSharper消息就会消失。
更新
我通过ExternalAnnotations找到了解决方案,Mike也在下面提到过。这是一个如何为Microsoft.Contracts中的函数执行此操作的示例:
Microsoft.Contracts
ReSharper目录下创建一个名为ExternalAnnotations
的目录。Microsoft.Contracts.xml
的文件并填充如下:
<assembly name="Microsoft.Contracts">
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
</assembly>
答案 0 :(得分:43)
注意:从当前的R#8.0 EAP开始,此功能已包含在内。
以下是代码合同当前(即.NET 4.0)版本的解决方案:
在...\ExternalAnnotations\mscorlib\Contracts.xml
内添加以下内容:
<assembly name="mscorlib">
<member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean, System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean, System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
</assembly>
答案 1 :(得分:18)
我想补充一点,对于编写自己的断言方法等的人来说,可以在没有外部XML文件的情况下包含这些属性。在Visual Studio中,转到ReSharper > Options > Code Annotations
,然后单击Copy default implementation to clipboard
按钮。然后创建一个新文件(在解决方案中的任何位置)并粘贴剪贴板中的代码。现在,您可以创建如下方法:
public class Require
{
[AssertionMethod]
public static void That(
[AssertionCondition(AssertionConditionType.IS_TRUE)]
bool requiredCondition,
string message = null)
{
...
}
...
}
现在,对Require.That(a != null)
的任何调用都会向ReSharper表明,如果a
为空,则无法通过此行。与ExternalAnnotations技术不同,这适用于使用您的方法的任何人,而无需任何额外的工作。
Resharper从版本7开始更改了合同注释模型。以下是上述方法的样子:
public class Require
{
[ContractAnnotation("requiredCondition:false => halt")]
public static void That(
bool requiredCondition,
string message = null)
{
...
}
...
}
答案 2 :(得分:5)
我认为你可以,但这不是微不足道的。看看Resharper online help for code annotation
他们注释了BCL类和NUnit框架(以及更多)以增强Resharpers代码检查功能。
例如,使用NUnit断言,它们使用AssertionMethodAttribute进行注释。这告诉Resharpers代码检查,如果你通过Assert.IsNotNull(foo);那么foo一定不能为null,它不会产生“可能'null'赋值......”警告。
您可以生成一个注释Contracts.Requires方法的xml文件,以指示它就像Assert一样。
答案 3 :(得分:4)
删除断言时消息消失的原因是默认情况下R#在“乐观”模式下工作。它假设一切都是非空的,直到你做了一些表明它实际上可以为空的东西。当您将调用添加到String.IsNullOrEmpty
时会发生这种情况。您说明s
实际上可能为空。它只是不知道如果是这种情况,Contract.Requires
方法将停止执行,但是你用注释解决了。
在R#5.0中,你可以改为悲观模式,假设每个角落都是最差的。
答案 4 :(得分:3)
我使用了Porges的XML并添加了Assert和Assume方法的注释。如果其他人想要添加更多方法,我会维基这个答案。
<assembly name="mscorlib">
<member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean, System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean, System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<parameter name="condition">
<attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
<argument>0</argument>
</attribute>
</parameter>
</member>
</assembly>
答案 5 :(得分:2)
从版本7开始,Resharper更改了合同注释模型。
您需要一个不同的文件。新位置(我猜只适用于Metro应用)是: “C:\ Program Files(x86)\ JetBrains \ ReSharper \ v7.1 \ Bin \ ExternalAnnotations \ .NETCore \ System.Diagnostics.Contracts \ Contracts.xml”
我正在使用Visual Studio 2012和.Net 4.5和Resharper 7.1。
内容:
<assembly name="System.Diagnostics.Contracts">
<member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean, System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean, System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
<member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)">
<attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
<attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
<argument>condition:false=>halt</argument>
</attribute>
</member>
</assembly>
答案 6 :(得分:0)
TL; DR - 将条件编译符号CONTRACTS_FULL
添加到项目中。
Contract.Requires(...)
方法为空并禁用,除非您启用并使用代码联系人重写器。通过手动运行重写器,或(通常)通过Visual Studio项目属性启用它,您将在编译和重写的二进制文件中保留Contract.Requires(...)
代码。您知道代码将起作用,并忽略Resharper警告,您可以运行它并进行测试。
那么问题是什么? Resharper不知道代码契约正在运行,因为它们实际上只在(后)编译时注入。在Resharper的眼中,它的禁用方式与DEBUG
预处理程序符号的工作方式相同,以及Visual Studio如何使代码区域不会成为已编译二进制文件的一部分。
#ifdef DEBUG
Console.WriteLine("I'm in DEBUG mode, so this is probably a Debug build.");
#else
Console.WriteLine("Let's assume this is a Release build.");
#endif
根据Code Contracts user manual(第2章,第1段)和ContractExtensions.cs
中的源代码(包含在Code Contracts安装文件夹中),在编译之前需要设置CONTRACTS_FULL
它。 The Contract methods are actually implemented [ConditionalAttribute("CONTRACTS_FULL")]
并忽略(编译时不包括),除非设置了标志。 Resharper尊重此标志,并假定除非设置该函数,否则该函数不会运行。
[ConditionalAttribute("CONTRACTS_FULL")]
public static void Requires(bool condition) { ... }
解决方案:将条件编译符号CONTRACTS_FULL
添加到项目中。见Henning Krause的Using Code Contracts Visual Studio and with Resharper。
Resharper团队已收到通知; Code analysis doesn't consider settings on the 'Code Contracts' project properties tab,Support of Microsoft Code Contracts。