5bff87abb4
* Modify rule S1479: allow statements with single-line clauses only * Improve compliant example * Improve description to match implementation * Address comments --------- Co-authored-by: Sebastien Marichal <sebastien.marichal@sonarsource.com>
89 lines
2.3 KiB
Plaintext
89 lines
2.3 KiB
Plaintext
== Why is this an issue?
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When https://learn.microsoft.com/en-us/dotnet/visual-basic/language-reference/statements/select-case-statement[Select Case] statements have large sets of multi-line `Case` clauses, the code becomes hard to read and maintain.
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For example, the https://www.sonarsource.com/docs/CognitiveComplexity.pdf[Cognitive Complexity] is going to be particularly high.
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In such scenarios, it's better to refactor the `Select Case` to only have single-line case clauses.
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When all the `Case` clauses of a `Select Case` statement are single-line, the readability of the code is not affected.
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=== Exceptions
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This rule ignores:
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* `Select Case` statements over `Enum` arguments
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* fall-through cases
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* `Return` and `Throw` statements in `Case` clauses
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== How to fix it
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Extract the logic of multi-line `Case` clauses into separate methods.
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=== Code examples
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The examples below use the "Maximum number of case" property set to `4`.
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==== Noncompliant code example
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[source,vbnet,diff-id=1,diff-type=noncompliant]
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----
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Public Function MapChar(ch As Char, value As Integer) As Integer ' Noncompliant
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Select Case ch
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Case "a"c
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Return 1
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Case "b"c
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Return 2
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Case "c"c
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Return 3
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' ...
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Case "-"c
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If value > 10 Then
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Return 42
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ElseIf value < 5 AndAlso value > 1 Then
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Return 21
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End If
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Return 99
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Case Else
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Return 1000
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End Select
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End Function
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----
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==== Compliant solution
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[source,vbnet,diff-id=1,diff-type=compliant]
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----
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Public Function MapChar(ch As Char, value As Integer) As Integer
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Select Case ch
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Case "a"c
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Return 1
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Case "b"c
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Return 2
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Case "c"c
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Return 3
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' ...
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Case "-"c
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Return HandleDash(value)
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Case Else
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Return 1000
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End Select
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End Function
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Private Function HandleDash(value As Integer) As Integer
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If value > 10 Then
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Return 42
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ElseIf value < 5 AndAlso value > 1 Then
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Return 21
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End If
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Return 99
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End Function
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----
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include::../resources-dotnet.adoc[]
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* Microsoft Learn - https://learn.microsoft.com/en-us/dotnet/visual-basic/language-reference/statements/select-case-statement[Select...Case Statement]
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include::../rspecator-dotnet.adoc[]
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