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SonarQube analyzer for Go language

There is a newer version: 1.24.0.3049

Why is this an issue?
When the same code is duplicated in two or more separate branches of a conditional, it can make the code harder to understand, maintain, and can
potentially introduce bugs if one instance of the code is changed but others are not.
Having two cases in a switch statement or two branches in an if chain with the same implementation is at
best duplicate code, and at worst a coding error.
if a >= 0 && a < 10 {
	doFirstThing()
	doSomething()
} else if a >= 10 && a < 20 {
	doSomethingElse()
} else if a >= 20 && a < 50 { // Noncompliant; duplicates first condition
	doFirstThing()
	doSomething()
} else {
	doTheRest()
}

switch i {
case 1:
	doFirstThing()
	doSomething()
case 2:
	doSomethingElse()
case 3: // Noncompliant; duplicates case 1's implementation
	doFirstThing()
	doSomething()
default:
	doTheRest()
}

If the same logic is truly needed for both instances, then:

   in an if chain they should be combined 

if (a >= 0 && a < 10) || (a >= 20 && a < 50) {
	doFirstThing()
	doSomething()
} else if a >= 10 && a < 20 {
	doSomethingElse()
} else {
	doTheRest()
}


   for a switch, the values should be put in the case expression list. 

switch i {
case 1, 3:
	doFirstThing()
	doSomething()
case 2:
	doSomethingElse()
default:
	doTheRest()
}

Exceptions
Blocks in an if chain or case blocks that contain a single line of code are ignored.
if a == 1 {
  doSomething()  //no issue, usually this is done on purpose to increase the readability
} else if a == 2 {
  doSomethingElse()
} else {
  doSomething()
}

Resources
Related rules

   {rule:go:S3923} - All branches in a conditional structure should not have exactly the same implementation