107 lines
2.1 KiB
Go
Vendored
107 lines
2.1 KiB
Go
Vendored
package rule
|
|
|
|
import (
|
|
"go/ast"
|
|
"go/token"
|
|
|
|
"github.com/mgechev/revive/lint"
|
|
)
|
|
|
|
// UnnecessaryStmtRule warns on unnecessary statements.
|
|
type UnnecessaryStmtRule struct{}
|
|
|
|
// Apply applies the rule to given file.
|
|
func (r *UnnecessaryStmtRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
|
|
var failures []lint.Failure
|
|
onFailure := func(failure lint.Failure) {
|
|
failures = append(failures, failure)
|
|
}
|
|
|
|
w := lintUnnecessaryStmtRule{onFailure}
|
|
ast.Walk(w, file.AST)
|
|
return failures
|
|
}
|
|
|
|
// Name returns the rule name.
|
|
func (r *UnnecessaryStmtRule) Name() string {
|
|
return "unnecessary-stmt"
|
|
}
|
|
|
|
type lintUnnecessaryStmtRule struct {
|
|
onFailure func(lint.Failure)
|
|
}
|
|
|
|
func (w lintUnnecessaryStmtRule) Visit(node ast.Node) ast.Visitor {
|
|
switch n := node.(type) {
|
|
case *ast.FuncDecl:
|
|
if n.Body == nil || n.Type.Results != nil {
|
|
return w
|
|
}
|
|
stmts := n.Body.List
|
|
if len(stmts) == 0 {
|
|
return w
|
|
}
|
|
|
|
lastStmt := stmts[len(stmts)-1]
|
|
rs, ok := lastStmt.(*ast.ReturnStmt)
|
|
if !ok {
|
|
return w
|
|
}
|
|
|
|
if len(rs.Results) == 0 {
|
|
w.newFailure(lastStmt, "omit unnecessary return statement")
|
|
}
|
|
|
|
case *ast.SwitchStmt:
|
|
w.checkSwitchBody(n.Body)
|
|
case *ast.TypeSwitchStmt:
|
|
w.checkSwitchBody(n.Body)
|
|
case *ast.CaseClause:
|
|
if n.Body == nil {
|
|
return w
|
|
}
|
|
stmts := n.Body
|
|
if len(stmts) == 0 {
|
|
return w
|
|
}
|
|
|
|
lastStmt := stmts[len(stmts)-1]
|
|
rs, ok := lastStmt.(*ast.BranchStmt)
|
|
if !ok {
|
|
return w
|
|
}
|
|
|
|
if rs.Tok == token.BREAK && rs.Label == nil {
|
|
w.newFailure(lastStmt, "omit unnecessary break at the end of case clause")
|
|
}
|
|
}
|
|
|
|
return w
|
|
}
|
|
|
|
func (w lintUnnecessaryStmtRule) checkSwitchBody(b *ast.BlockStmt) {
|
|
cases := b.List
|
|
if len(cases) != 1 {
|
|
return
|
|
}
|
|
|
|
cc, ok := cases[0].(*ast.CaseClause)
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
if len(cc.List) > 1 { // skip cases with multiple expressions
|
|
return
|
|
}
|
|
|
|
w.newFailure(b, "switch with only one case can be replaced by an if-then")
|
|
}
|
|
|
|
func (w lintUnnecessaryStmtRule) newFailure(node ast.Node, msg string) {
|
|
w.onFailure(lint.Failure{
|
|
Confidence: 1,
|
|
Node: node,
|
|
Category: "style",
|
|
Failure: msg,
|
|
})
|
|
}
|