Potential false positive: variable used in multiple if statements

[sbueringer]

I'm not sure if it's intentional but the following code produces a finding:

	isDeleteNodeAllowed := err == nil

	if isDeleteNodeAllowed {
		fmt.Println("abc")
	}

	if isDeleteNodeAllowed {
		fmt.Println("def")
	}

controllers/machine_controller.go:278:2: variable 'isDeleteNodeAllowed' is only used in the if-statement (controllers/machine_controller.go:280:2); consider using short syntax (ifshort)
        isDeleteNodeAllowed := err == nil
        ^

(full original code can be seen here, but the short version above also produces the finding)

In case it's not intentional, I think the problem is that getNamedOccurrenceMap=>addFromCondition only adds one occurrence for the first if. The second if is not added as additional occurrence because addFromIdent=>occ.isComplete returns true.

Interestingly this issue is only reported in ~90-95% of the cases when ifshort is run.

Context: We are running ifshort via golangci-lint and we are also running the nolint linter.
For some reason that finding (on the original code) is not reported on every run. We've added a nolint statement, but in those cases where ifshort does not report the finding we'll get a finding that the nolint statement is not required.

[esimonov]

Could you please advise what version of golangci-lint are you using? I ran v1.42.1 on the following function ten times in a row and it didn't report any findings.

func notUsed_IfStmt_MultipleIfStmt_OK() {
	err := getValue()
	isDeleteNodeAllowed := err == nil

	if isDeleteNodeAllowed {
		fmt.Println("abc")
	}

	if isDeleteNodeAllowed {
		fmt.Println("def")
	}
}

[sbueringer]

I'm using v1.43.0

[sbueringer]

Sorry as a full example:

main.go:

package main

import (
	"fmt"
)

func main() {
	err := fmt.Errorf("test")
	isDeleteNodeAllowed := err == nil

	if isDeleteNodeAllowed {
		fmt.Println("abc")
	}

	if isDeleteNodeAllowed {
		fmt.Println("def")
	}
}

.golangci.yml:

linters:
  disable-all: true
  enable:
  - ifshort

linters-settings:
  ifshort:
    # Maximum length of variable declaration measured in number of characters, after which linter won't suggest using short syntax.
    max-decl-chars: 50

output:

main.go:11:2: variable 'isDeleteNodeAllowed' is only used in the if-statement (main.go:9:2); consider using short syntax (ifshort)
        isDeleteNodeAllowed := err == nil

[Walz]

I encountered a similar issue, I've been able to reproduce it with the following code:
main.go

package main

func main() {
	x := 0

	for i := 0; i < 10; i++ {
		if i%2 == 0 {
			continue
		} else {
			x++
		}
	}

	if x > 0 {
		println(x)
	}
}

And the output of golangci-lint:

main.go:5:2: variable 'x' is only used in the if-statement (cmd/main.go:15:2); consider using short syntax (ifshort)
	x := 0
	^

x is used in the else and the second if.
I'm using golangci-lint 1.43.0.

[korya]

Another case where a similar false positive occurs:

err := doSomething()

doSomethingElse()

if err != nil {
    fmr.Printf("Failed: %s\n", err)
}

I am using golangci-lint v1.43.0 as well.