75 lines
1.4 KiB
Go
75 lines
1.4 KiB
Go
package rule
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import (
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"fmt"
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"go/ast"
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"go/token"
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"github.com/mgechev/revive/lint"
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)
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// IncrementDecrementRule lints given else constructs.
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type IncrementDecrementRule struct{}
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// Apply applies the rule to given file.
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func (r *IncrementDecrementRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
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var failures []lint.Failure
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fileAst := file.AST
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walker := lintIncrementDecrement{
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file: file,
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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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ast.Walk(walker, fileAst)
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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 *IncrementDecrementRule) Name() string {
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return "increment-decrement"
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}
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type lintIncrementDecrement struct {
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file *lint.File
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fileAst *ast.File
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onFailure func(lint.Failure)
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}
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func (w lintIncrementDecrement) Visit(n ast.Node) ast.Visitor {
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as, ok := n.(*ast.AssignStmt)
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if !ok {
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return w
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}
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if len(as.Lhs) != 1 {
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return w
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}
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if !isOne(as.Rhs[0]) {
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return w
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}
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var suffix string
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switch as.Tok {
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case token.ADD_ASSIGN:
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suffix = "++"
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case token.SUB_ASSIGN:
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suffix = "--"
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default:
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return w
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}
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w.onFailure(lint.Failure{
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Confidence: 0.8,
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Node: as,
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Category: "unary-op",
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Failure: fmt.Sprintf("should replace %s with %s%s", w.file.Render(as), w.file.Render(as.Lhs[0]), suffix),
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})
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return w
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}
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func isOne(expr ast.Expr) bool {
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lit, ok := expr.(*ast.BasicLit)
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return ok && lit.Kind == token.INT && lit.Value == "1"
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}
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