1 // Copyright 2020 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // Package noresultvalues defines an Analyzer that applies suggested fixes
6 // to errors of the type "no result values expected".
14 "golang.org/x/tools/go/analysis"
15 "golang.org/x/tools/go/analysis/passes/inspect"
16 "golang.org/x/tools/go/ast/inspector"
17 "golang.org/x/tools/internal/analysisinternal"
20 const Doc = `suggested fixes for "no result values expected"
22 This checker provides suggested fixes for type errors of the
23 type "no result values expected". For example:
24 func z() { return nil }
29 var Analyzer = &analysis.Analyzer{
30 Name: string(analysisinternal.NoResultValues),
32 Requires: []*analysis.Analyzer{inspect.Analyzer},
34 RunDespiteErrors: true,
37 func run(pass *analysis.Pass) (interface{}, error) {
38 inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
39 errors := analysisinternal.GetTypeErrors(pass)
41 nodeFilter := []ast.Node{(*ast.ReturnStmt)(nil)}
42 inspect.Preorder(nodeFilter, func(n ast.Node) {
43 retStmt, _ := n.(*ast.ReturnStmt)
46 for _, f := range pass.Files {
47 if f.Pos() <= retStmt.Pos() && retStmt.Pos() < f.End() {
56 for _, err := range errors {
57 if !FixesError(err.Msg) {
60 if retStmt.Pos() >= err.Pos || err.Pos >= retStmt.End() {
64 if err := format.Node(&buf, pass.Fset, file); err != nil {
67 pass.Report(analysis.Diagnostic{
69 End: analysisinternal.TypeErrorEndPos(pass.Fset, buf.Bytes(), err.Pos),
71 SuggestedFixes: []analysis.SuggestedFix{{
72 Message: "Delete return values",
73 TextEdits: []analysis.TextEdit{{
76 NewText: []byte("return"),
85 func FixesError(msg string) bool {
86 return msg == "no result values expected"