rspec/rules/S2583/csharp/rule.adoc

== Why is this an issue?

include::../description.adoc[]

In the case below, the call of `Dispose()` never happens.

[source,csharp]
----
var a = false;
if (a)
{
    Dispose(); // Never reached
}
----

=== Exceptions

This rule will not raise an issue in either of these cases:

* When the condition is a single `const bool`
+
[source,csharp]
----
const bool debug = false;
//...
if (debug)
{
  // Print something
}
----
* When the condition is the literal `true` or `false`.

In these cases, it is obvious the code is as intended.

== How to fix it

The conditions should be reviewed to decide whether:

* to update the condition or
* to remove the condition.

=== Code examples

==== Noncompliant code example

[source,csharp,diff-id=1,diff-type=noncompliant]
----
public void Sample(bool b)
{
    bool a = false;
    if (a)                  // Noncompliant: The true branch is never reached
    {
        DoSomething();      // Never reached
    }

    if (!a || b)            // Noncompliant: "!a" is always "true" and the false branch is never reached
    {
        DoSomething();
    }
    else
    {
        DoSomethingElse();  // Never reached
    }

    var c = "xxx";
    var res = c ?? "value"; // Noncompliant: c is always not null, "value" is never used
}
----

==== Compliant solution

[source,csharp,diff-id=1,diff-type=compliant]
----
public void Sample(bool b)
{
    bool a = false;
    if (Foo(a))             // Condition was updated
    {
        DoSomething();
    }

    if (b)                  // Parts of the condition were removed.
    {
        DoSomething();
    }
    else
    {
        DoSomethingElse();
    }

    var c = "xxx";
    var res = c;            // ?? "value" was removed
}
----

include::../see.adoc[]

=== Documentation

* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/boolean-logical-operators#conditional-logical-and-operator-[Conditional logical AND operator &&]
* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/boolean-logical-operators#conditional-logical-or-operator-[Conditional logical OR operator ||]
* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/null-coalescing-operator[?? and ??= operators - the null-coalescing operators]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

* Change this condition so that it does not always evaluate to "[true|false]". Some code paths are unreachable.
* Change this expression which always evaluates to the same result. Some code paths are unreachable.


include::../highlighting.adoc[]

'''
== Comments And Links
(visible only on this page)

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

endif::env-github,rspecator-view[]