83 lines
1.6 KiB
Go
83 lines
1.6 KiB
Go
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package rule
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import (
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"go/ast"
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"github.com/mgechev/revive/lint"
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)
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// IdenticalBranchesRule warns on constant logical expressions.
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type IdenticalBranchesRule struct{}
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// Apply applies the rule to given file.
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func (r *IdenticalBranchesRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
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var failures []lint.Failure
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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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astFile := file.AST
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w := &lintIdenticalBranches{astFile, onFailure}
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ast.Walk(w, astFile)
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return failures
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}
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// Name returns the rule name.
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func (r *IdenticalBranchesRule) Name() string {
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return "identical-branches"
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}
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type lintIdenticalBranches struct {
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file *ast.File
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onFailure func(lint.Failure)
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}
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func (w *lintIdenticalBranches) Visit(node ast.Node) ast.Visitor {
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n, ok := node.(*ast.IfStmt)
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if !ok {
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return w
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}
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if n.Else == nil {
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return w
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}
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branches := []*ast.BlockStmt{n.Body}
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elseBranch, ok := n.Else.(*ast.BlockStmt)
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if !ok { // if-else-if construction
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return w
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}
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branches = append(branches, elseBranch)
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if w.identicalBranches(branches) {
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w.newFailure(n, "both branches of the if are identical")
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}
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return w
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}
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func (w *lintIdenticalBranches) identicalBranches(branches []*ast.BlockStmt) bool {
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if len(branches) < 2 {
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return false
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}
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ref := gofmt(branches[0])
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for i := 1; i < len(branches); i++ {
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if gofmt(branches[i]) != ref {
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return false
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}
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}
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return true
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}
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func (w lintIdenticalBranches) newFailure(node ast.Node, msg string) {
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w.onFailure(lint.Failure{
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Confidence: 1,
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Node: node,
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Category: "logic",
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Failure: msg,
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})
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}
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