[go1.19] cmd/gofmt: machine-readable (//nolint) comments should not be reformatted

[thaJeztah]

GoLangCI-lint documentation https://golangci-lint.run/usage/false-positives/

Use //nolint instead of // nolint because machine-readable comments should have no space by Go convention.

I think some improvements may have been made between rc1 and rc2, but I still noticed some diffs

What version of Go are you using (go version)?

$ go version
go version go1.19rc2 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
# not relevant

What did you do?

Formatted code with gofmt

What did you expect to see?

Machine-readable comments, such as //nolint: <some linter> or //#nosec XXX preserving their formatting

What did you see instead?

gofmt reformatting those comments to add a leading whitespace (// nolint: <some linter> , // #nosec

The following go file should not produce a diff after running gofmt;

package main

import "fmt"

// Some variables that are defined here
//
//nolint:govet
var (
	var1 int //#nosec G501
	var2 int
)

// foo is something
//nolint: gosimple
var var3 = "foo"

// bar is something
//
//nolint: gosimple
var var4 = "bar"

func main() {
	//#nosec G305 -- Some comment here
	var5 := "hello"

	fmt.Println(var1, var2, var3, var4, var5)
}

// function1 does something.
//nolint
func function1() {}

// function2 does something.
//
//nolint:gocyclo
func function2() {}

// function3 does something.
//
//nolint:gocyclo // Some comment here
func function3() {}

//nolint
func function4() {}

//nolint:gocyclo // Some comment here
func function5() {}

func function6() { //nolint
}

func function7() { //nolint:gocyclo // Some comment here
}

// function1 does something.
//#nosec G305 -- Some comment here
func function8() {}

// function2 does something.
//
//#nosec G305 -- Some comment here
func function9() {}

//#nosec G305 -- Some comment here
func function10() {}

//#nosec G305
func function11() {}

func function12() { //#nosec G305
}

func function13() { //#nosec G305 -- Some comment here
}

type Foo struct{}

// Method1 does something
//
//nolint: gocyclo
func (p *Foo) Method1() {}

// Method2 does something
//
//nolint:gocyclo
func (p *Foo) Method2() {}

// Method3 does something
//nolint:gocyclo
func (p *Foo) Method3() {}

// Method4 does something
//nolint
func (p *Foo) Method4() {}

[mvdan]

See golangci/golangci-lint#1658, which seems like a better fix that does not require workarounds in gofmt. Plus, that way we move the broader Go ecosystem further towards the standard comment directive format.

[seankhliao]

This was raised in #37974 (comment) and following comments. There doesn't appear to be any new info here.

Closing as dup.

[thaJeztah]

Ah, thanks for those links (sorry I didn't find those);

right, so IIUC, the requirements are:

• No space (//nolint)
• MUST start with alpha-numeric (so //#nosec is invalid because #)
• MUST have a colon (//nolint:)
• MUST have text following it, but MUST NOT have whitespace (✅ //nolint:something,foo,bar ❌ //nolint: foo, bar)

Which explains why the //nolint (no colon) and //nolint: foo (colon but whitespace) are reformatted as regular comment

diff --git a/./main.go.backup b/./main.go
index e7ca9cb..de570f6 100644
--- a/./main.go.backup
+++ b/./main.go
@@ -11,12 +11,12 @@ var (
 )
 
 // foo is something
-//nolint: gosimple
+// nolint: gosimple
 var var3 = "foo"
 
 // bar is something
 //
-//nolint: gosimple
+// nolint: gosimple
 var var4 = "bar"
 
 func main() {
@@ -27,7 +27,7 @@ func main() {
 }
 
 // function1 does something.
-//nolint
+// nolint
 func function1() {}
 
 // function2 does something.
@@ -40,7 +40,7 @@ func function2() {}
 //nolint:gocyclo // Some comment here
 func function3() {}
 
-//nolint
+// nolint
 func function4() {}
 
 //nolint:gocyclo // Some comment here
@@ -53,18 +53,18 @@ func function7() { //nolint:gocyclo // Some comment here
 }
 
 // function1 does something.
-//#nosec G305 -- Some comment here
+// #nosec G305 -- Some comment here
 func function8() {}
 
 // function2 does something.
 //
-//#nosec G305 -- Some comment here
+// #nosec G305 -- Some comment here
 func function9() {}
 
-//#nosec G305 -- Some comment here
+// #nosec G305 -- Some comment here
 func function10() {}
 
-//#nosec G305
+// #nosec G305
 func function11() {}
 
 func function12() { //#nosec G305
@@ -77,7 +77,7 @@ type Foo struct{}
 
 // Method1 does something
 //
-//nolint: gocyclo
+// nolint: gocyclo
 func (p *Foo) Method1() {}
 
 // Method2 does something
@@ -86,9 +86,10 @@ func (p *Foo) Method1() {}
 func (p *Foo) Method2() {}
 
 // Method3 does something
+//
 //nolint:gocyclo
 func (p *Foo) Method3() {}
 
 // Method4 does something
-//nolint
+// nolint
 func (p *Foo) Method4() {}