Add staticcheck tool

vendor/honnef.co/go/tools/staticcheck/sa4013/sa4013.go

@@ -0,0 +1,40 @@
+package sa4013
+
+import (
+	"go/ast"
+
+	"honnef.co/go/tools/analysis/code"
+	"honnef.co/go/tools/analysis/edit"
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/analysis/report"
+	"honnef.co/go/tools/pattern"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name:     "SA4013",
+		Run:      run,
+		Requires: code.RequiredAnalyzers,
+	},
+	Doc: &lint.RawDocumentation{
+		Title:    `Negating a boolean twice (\'!!b\') is the same as writing \'b\'. This is either redundant, or a typo.`,
+		Since:    "2017.1",
+		Severity: lint.SeverityWarning,
+		MergeIf:  lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+var checkDoubleNegationQ = pattern.MustParse(`(UnaryExpr "!" single@(UnaryExpr "!" x))`)
+
+func run(pass *analysis.Pass) (any, error) {
+	for node, m := range code.Matches(pass, checkDoubleNegationQ) {
+		report.Report(pass, node, "negating a boolean twice has no effect; is this a typo?", report.Fixes(
+			edit.Fix("Turn into single negation", edit.ReplaceWithNode(pass.Fset, node, m.State["single"].(ast.Node))),
+			edit.Fix("Remove double negation", edit.ReplaceWithNode(pass.Fset, node, m.State["x"].(ast.Node)))))
+	}
+	return nil, nil
+}