45 lines
1.3 KiB
Go
45 lines
1.3 KiB
Go
package s1010
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import (
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"go/ast"
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"honnef.co/go/tools/analysis/code"
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"honnef.co/go/tools/analysis/edit"
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"honnef.co/go/tools/analysis/facts/generated"
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"honnef.co/go/tools/analysis/lint"
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"honnef.co/go/tools/analysis/report"
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"honnef.co/go/tools/pattern"
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"golang.org/x/tools/go/analysis"
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)
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var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
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Analyzer: &analysis.Analyzer{
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Name: "S1010",
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Run: run,
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Requires: append([]*analysis.Analyzer{generated.Analyzer}, code.RequiredAnalyzers...),
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},
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Doc: &lint.RawDocumentation{
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Title: `Omit default slice index`,
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Text: `When slicing, the second index defaults to the length of the value,
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making \'s[n:len(s)]\' and \'s[n:]\' equivalent.`,
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Since: "2017.1",
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MergeIf: lint.MergeIfAny,
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},
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})
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var Analyzer = SCAnalyzer.Analyzer
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var checkSlicingQ = pattern.MustParse(`(SliceExpr x@(Object _) low (CallExpr (Builtin "len") [x]) nil)`)
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func run(pass *analysis.Pass) (any, error) {
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for node := range code.Matches(pass, checkSlicingQ) {
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expr := node.(*ast.SliceExpr)
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report.Report(pass, expr.High,
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"should omit second index in slice, s[a:len(s)] is identical to s[a:]",
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report.FilterGenerated(),
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report.Fixes(edit.Fix("Simplify slice expression", edit.Delete(expr.High))))
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}
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return nil, nil
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}
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