81 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package rule
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| 
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| import (
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| 	"fmt"
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| 	"go/ast"
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| 
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| 	"github.com/mgechev/revive/lint"
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| )
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| 
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| // ModifiesParamRule lints given else constructs.
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| type ModifiesParamRule struct{}
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| 
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| // Apply applies the rule to given file.
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| func (r *ModifiesParamRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
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| 	var failures []lint.Failure
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| 
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| 	onFailure := func(failure lint.Failure) {
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| 		failures = append(failures, failure)
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| 	}
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| 
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| 	w := lintModifiesParamRule{onFailure: onFailure}
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| 	ast.Walk(w, file.AST)
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| 	return failures
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| }
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| 
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| // Name returns the rule name.
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| func (r *ModifiesParamRule) Name() string {
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| 	return "modifies-parameter"
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| }
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| 
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| type lintModifiesParamRule struct {
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| 	params    map[string]bool
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| 	onFailure func(lint.Failure)
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| }
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| 
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| func retrieveParamNames(pl []*ast.Field) map[string]bool {
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| 	result := make(map[string]bool, len(pl))
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| 	for _, p := range pl {
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| 		for _, n := range p.Names {
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| 			if n.Name == "_" {
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| 				continue
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| 			}
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| 
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| 			result[n.Name] = true
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| 		}
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| 	}
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| 	return result
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| }
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| 
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| func (w lintModifiesParamRule) Visit(node ast.Node) ast.Visitor {
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| 	switch v := node.(type) {
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| 	case *ast.FuncDecl:
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| 		w.params = retrieveParamNames(v.Type.Params.List)
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| 	case *ast.IncDecStmt:
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| 		if id, ok := v.X.(*ast.Ident); ok {
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| 			checkParam(id, &w)
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| 		}
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| 	case *ast.AssignStmt:
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| 		lhs := v.Lhs
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| 		for _, e := range lhs {
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| 			id, ok := e.(*ast.Ident)
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| 			if ok {
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| 				checkParam(id, &w)
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| 			}
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| 		}
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| 	}
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| 
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| 	return w
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| }
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| 
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| func checkParam(id *ast.Ident, w *lintModifiesParamRule) {
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| 	if w.params[id.Name] {
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| 		w.onFailure(lint.Failure{
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| 			Confidence: 0.5, // confidence is low because of shadow variables
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| 			Node:       id,
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| 			Category:   "bad practice",
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| 			Failure:    fmt.Sprintf("parameter '%s' seems to be modified", id),
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| 		})
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| 	}
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| }
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