github.com/amarpal/go-tools@v0.0.0-20240422043104-40142f59f616/staticcheck/sa1018/sa1018.go (about)

     1  package sa1018
     2  
     3  import (
     4  	"fmt"
     5  	"go/constant"
     6  
     7  	"github.com/amarpal/go-tools/analysis/callcheck"
     8  	"github.com/amarpal/go-tools/analysis/lint"
     9  	"github.com/amarpal/go-tools/go/ir"
    10  	"github.com/amarpal/go-tools/internal/passes/buildir"
    11  
    12  	"golang.org/x/tools/go/analysis"
    13  )
    14  
    15  var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
    16  	Analyzer: &analysis.Analyzer{
    17  		Name:     "SA1018",
    18  		Requires: []*analysis.Analyzer{buildir.Analyzer},
    19  		Run:      callcheck.Analyzer(rules),
    20  	},
    21  	Doc: &lint.Documentation{
    22  		Title: `\'strings.Replace\' called with \'n == 0\', which does nothing`,
    23  		Text: `With \'n == 0\', zero instances will be replaced. To replace all
    24  instances, use a negative number, or use \'strings.ReplaceAll\'.`,
    25  		Since:    "2017.1",
    26  		Severity: lint.SeverityWarning,
    27  		MergeIf:  lint.MergeIfAny, // MergeIfAny if we only flag literals, not named constants
    28  	},
    29  })
    30  
    31  var Analyzer = SCAnalyzer.Analyzer
    32  
    33  var rules = map[string]callcheck.Check{
    34  	"strings.Replace": check("strings.Replace", 3),
    35  	"bytes.Replace":   check("bytes.Replace", 3),
    36  }
    37  
    38  func check(name string, arg int) callcheck.Check {
    39  	return func(call *callcheck.Call) {
    40  		arg := call.Args[arg]
    41  		if k, ok := arg.Value.Value.(*ir.Const); ok && k.Value.Kind() == constant.Int {
    42  			if v, ok := constant.Int64Val(k.Value); ok && v == 0 {
    43  				arg.Invalid(fmt.Sprintf("calling %s with n == 0 will return no results, did you mean -1?", name))
    44  			}
    45  		}
    46  	}
    47  }