rspec/rules/S1121/csharp/rule.adoc

== Why is this an issue?

include::../description.adoc[]

=== Exceptions

Assignments inside lambda and delegate expressions are allowed.

[source,csharp]
----
var result = Foo(() =>
{
   int x = 100; // dead store, but ignored
   x = 200;
   return x;
}
----

The rule also ignores the following patterns:

* Chained assignments

[source,csharp]
----
var a = b = c = 10;
----

* Assignments that are part of a condition of an `if` statement or a loop

[source,csharp]
----
while ((val = GetNewValue()) > 0)
{
...
}
----

* Assignment in the right-hand side of a coalescing operator

[source,csharp]
----
private MyClass instance;
public MyClass Instance => instance ?? (instance = new MyClass());
----

== How to fix it

include::../how-to-fix-it.adoc[]

=== Code examples

==== Noncompliant code example

[source,csharp,diff-id=1,diff-type=noncompliant]
----
if (string.IsNullOrEmpty(result = str.Substring(index, length))) // Noncompliant
{
  // do something with "result"
}
----

==== Compliant solution

[source,csharp,diff-id=1,diff-type=compliant]
----
var result = str.Substring(index, length);
if (string.IsNullOrEmpty(result))
{
  // do something with "result"
}
----

include::../see.adoc[]

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== Implementation Specification
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include::../message.adoc[]

include::../highlighting.adoc[]

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== Comments And Links
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=== on 21 Jan 2016, 11:09:06 Dinesh Bolkensteyn wrote:
This rule doesn't cover the R# compiler warning (which is out of the box in Roslyn).

See \https://msdn.microsoft.com/en-us/library/c1sde1ax.aspx for details on how that one behaves.


As this more generalized rule is way more crappy, I'm disabling it by default for C#

include::../comments-and-links.adoc[]

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