golang.org/x/tools@v0.21.0/go/analysis/passes/appends/appends.go (about) 1 // Copyright 2023 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. 4 5 // Package appends defines an Analyzer that detects 6 // if there is only one variable in append. 7 package appends 8 9 import ( 10 _ "embed" 11 "go/ast" 12 "go/types" 13 14 "golang.org/x/tools/go/analysis" 15 "golang.org/x/tools/go/analysis/passes/inspect" 16 "golang.org/x/tools/go/analysis/passes/internal/analysisutil" 17 "golang.org/x/tools/go/ast/inspector" 18 "golang.org/x/tools/go/types/typeutil" 19 ) 20 21 //go:embed doc.go 22 var doc string 23 24 var Analyzer = &analysis.Analyzer{ 25 Name: "appends", 26 Doc: analysisutil.MustExtractDoc(doc, "appends"), 27 URL: "https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/appends", 28 Requires: []*analysis.Analyzer{inspect.Analyzer}, 29 Run: run, 30 } 31 32 func run(pass *analysis.Pass) (interface{}, error) { 33 inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector) 34 35 nodeFilter := []ast.Node{ 36 (*ast.CallExpr)(nil), 37 } 38 inspect.Preorder(nodeFilter, func(n ast.Node) { 39 call := n.(*ast.CallExpr) 40 b, ok := typeutil.Callee(pass.TypesInfo, call).(*types.Builtin) 41 if ok && b.Name() == "append" && len(call.Args) == 1 { 42 pass.ReportRangef(call, "append with no values") 43 } 44 }) 45 46 return nil, nil 47 }