46 lines
1.6 KiB
Plaintext
46 lines
1.6 KiB
Plaintext
== Why is this an issue?
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When you use a https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/statements/using[`using` statement], the goal is to ensure the correct disposal of an https://learn.microsoft.com/en-us/dotnet/api/system.idisposable[`IDisposable`] instance when the control leaves the `using` statement block.
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If you return that `IDisposable` instance inside the block, `using` will dispose it before the caller can use it, likely causing exceptions at runtime. You should either remove `using` statement or avoid returning the `IDisposable` in the `using` statement block.
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== How to fix it
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=== Code examples
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==== Noncompliant code example
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[source,csharp,diff-id=1,diff-type=noncompliant]
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----
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public FileStream WriteToFile(string path, string text)
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{
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using (var fs = File.Create(path)) // Noncompliant: 'fs' is disposed at the end of the using scope
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{
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var bytes = Encoding.UTF8.GetBytes(text);
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fs.Write(bytes, 0, bytes.Length);
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return fs;
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}
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}
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----
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==== Compliant solution
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[source,csharp,diff-id=1,diff-type=compliant]
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----
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public FileStream WriteToFile(string path, string text)
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{
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var fs = File.Create(path);
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var bytes = Encoding.UTF8.GetBytes(text);
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fs.Write(bytes, 0, bytes.Length);
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return fs; // Compliant: 'fs' is not disposed once the end of the scope is reached and the caller can use it
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}
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----
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== Resources
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=== Documentation
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* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/statements/using[using statement - ensure the correct use of disposable objects]
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* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/api/system.idisposable[IDisposable]
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