fix: 'package-comments' false positive for CRLF sources

.gitattributes

@@ -0,0 +1,2 @@
+# These Go files must have CRLF endings
+testdata/package_comments_issue607*.go text eol=crlf

lint/file.go

@@ -29,6 +29,11 @@ func (f *File) Content() []byte {
 	return f.content
 }
 
+// IsCRLFTerminated returns if the file is terminated with CRLF.
+func (f *File) IsCRLFTerminated() bool {
+	return bytes.HasSuffix(f.content, []byte("\r\n"))
+}
+
 // NewFile creates a new file
 func NewFile(name string, content []byte, pkg *Package) (*File, error) {
 	f, err := parser.ParseFile(pkg.fset, name, content, parser.ParseComments)
@@ -48,6 +53,10 @@ func (f *File) ToPosition(pos token.Pos) token.Position {
 	return f.Pkg.fset.Position(pos)
 }
 
+func (f *File) Fset() *token.FileSet {
+	return f.Pkg.fset
+}
+
 // Render renders a node.
 func (f *File) Render(x any) string {
 	var buf bytes.Buffer

rule/package_comments.go

@@ -120,7 +120,12 @@ func (l *lintPackageComments) Visit(_ ast.Node) ast.Visitor {
 	if lastCG != nil && strings.HasPrefix(lastCG.Text(), prefix) {
 		endPos := l.file.ToPosition(lastCG.End())
 		pkgPos := l.file.ToPosition(l.fileAst.Package)
-		if endPos.Line+1 < pkgPos.Line {
+		isDetached := endPos.Line+1 < pkgPos.Line
+		if l.file.IsCRLFTerminated() {
+			// Workaround for https://github.com/mgechev/revive/issues/607
+			isDetached = endPos.Line+2 < pkgPos.Line
+		}
+		if isDetached {
 			// There isn't a great place to anchor this error;
 			// the start of the blank lines between the doc and the package statement
 			// is at least pointing at the location of the problem.

test/package_comments_test.go

@@ -0,0 +1,16 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/mgechev/revive/lint"
+	"github.com/mgechev/revive/rule"
+)
+
+func TestPackageCommentsIssue607NotMatch(t *testing.T) {
+	testRule(t, "package_comments_issue607_not_match", &rule.PackageCommentsRule{}, &lint.RuleConfig{})
+}
+
+func TestPackageCommentsIssue607Match(t *testing.T) {
+	testRule(t, "package_comments_issue607_match", &rule.PackageCommentsRule{}, &lint.RuleConfig{})
+}

testdata/package_comments_issue607_match.go

@@ -0,0 +1,8 @@
+/*
+Package fixtures has a multi-line comment.
+Its line endings have a carriage return.
+*/
+
+package fixtures
+
+// MATCH:4 /package comment is detached; there should be no blank lines between it and the package statement/

testdata/package_comments_issue607_not_match.go

@@ -0,0 +1,5 @@
+/*
+Package fixtures has a multi-line comment.
+Its line endings have a carriage return.
+*/
+package fixtures