gitea/vendor/github.com/mgechev/revive/rule/empty-lines.go

114 lines
2.2 KiB
Go

package rule
import (
"go/ast"
"go/token"
"github.com/mgechev/revive/lint"
)
// EmptyLinesRule lints empty lines in blocks.
type EmptyLinesRule struct{}
// Apply applies the rule to given file.
func (r *EmptyLinesRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
var failures []lint.Failure
onFailure := func(failure lint.Failure) {
failures = append(failures, failure)
}
w := lintEmptyLines{file, file.CommentMap(), onFailure}
ast.Walk(w, file.AST)
return failures
}
// Name returns the rule name.
func (r *EmptyLinesRule) Name() string {
return "empty-lines"
}
type lintEmptyLines struct {
file *lint.File
cmap ast.CommentMap
onFailure func(lint.Failure)
}
func (w lintEmptyLines) Visit(node ast.Node) ast.Visitor {
block, ok := node.(*ast.BlockStmt)
if !ok {
return w
}
w.checkStart(block)
w.checkEnd(block)
return w
}
func (w lintEmptyLines) checkStart(block *ast.BlockStmt) {
if len(block.List) == 0 {
return
}
start := w.position(block.Lbrace)
firstNode := block.List[0]
if w.commentBetween(start, firstNode) {
return
}
first := w.position(firstNode.Pos())
if first.Line-start.Line > 1 {
w.onFailure(lint.Failure{
Confidence: 1,
Node: block,
Category: "style",
Failure: "extra empty line at the start of a block",
})
}
}
func (w lintEmptyLines) checkEnd(block *ast.BlockStmt) {
if len(block.List) < 1 {
return
}
end := w.position(block.Rbrace)
lastNode := block.List[len(block.List)-1]
if w.commentBetween(end, lastNode) {
return
}
last := w.position(lastNode.End())
if end.Line-last.Line > 1 {
w.onFailure(lint.Failure{
Confidence: 1,
Node: lastNode,
Category: "style",
Failure: "extra empty line at the end of a block",
})
}
}
func (w lintEmptyLines) commentBetween(position token.Position, node ast.Node) bool {
comments := w.cmap.Filter(node).Comments()
if len(comments) == 0 {
return false
}
for _, comment := range comments {
start, end := w.position(comment.Pos()), w.position(comment.End())
if start.Line-position.Line == 1 || position.Line-end.Line == 1 {
return true
}
}
return false
}
func (w lintEmptyLines) position(pos token.Pos) token.Position {
return w.file.ToPosition(pos)
}