package rule import ( "go/ast" "github.com/mgechev/revive/lint" ) // BareReturnRule lints given else constructs. type BareReturnRule struct{} // Apply applies the rule to given file. func (r *BareReturnRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure { var failures []lint.Failure onFailure := func(failure lint.Failure) { failures = append(failures, failure) } w := lintBareReturnRule{onFailure: onFailure} ast.Walk(w, file.AST) return failures } // Name returns the rule name. func (r *BareReturnRule) Name() string { return "bare-return" } type lintBareReturnRule struct { onFailure func(lint.Failure) } func (w lintBareReturnRule) Visit(node ast.Node) ast.Visitor { switch n := node.(type) { case *ast.FuncDecl: w.checkFunc(n.Type.Results, n.Body) case *ast.FuncLit: // to cope with deferred functions and go-routines w.checkFunc(n.Type.Results, n.Body) } return w } // checkFunc will verify if the given function has named result and bare returns func (w lintBareReturnRule) checkFunc(results *ast.FieldList, body *ast.BlockStmt) { hasNamedResults := results != nil && len(results.List) > 0 && results.List[0].Names != nil if !hasNamedResults || body == nil { return // nothing to do } brf := bareReturnFinder{w.onFailure} ast.Walk(brf, body) } type bareReturnFinder struct { onFailure func(lint.Failure) } func (w bareReturnFinder) Visit(node ast.Node) ast.Visitor { _, ok := node.(*ast.FuncLit) if ok { // skip analysing function literals // they will analyzed by the lintBareReturnRule.Visit method return nil } rs, ok := node.(*ast.ReturnStmt) if !ok { return w } if len(rs.Results) > 0 { return w } w.onFailure(lint.Failure{ Confidence: 1, Node: rs, Failure: "avoid using bare returns, please add return expressions", }) return w }