Add staticcheck tool

vendor/honnef.co/go/tools/stylecheck/st1012/st1012.go

@@ -0,0 +1,68 @@
+package st1012
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+	"strings"
+
+	"honnef.co/go/tools/analysis/code"
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/analysis/report"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name: "ST1012",
+		Run:  run,
+	},
+	Doc: &lint.RawDocumentation{
+		Title: `Poorly chosen name for error variable`,
+		Text: `Error variables that are part of an API should be called \'errFoo\' or
+\'ErrFoo\'.`,
+		Since:   "2019.1",
+		MergeIf: lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+func run(pass *analysis.Pass) (any, error) {
+	for _, f := range pass.Files {
+		for _, decl := range f.Decls {
+			gen, ok := decl.(*ast.GenDecl)
+			if !ok || gen.Tok != token.VAR {
+				continue
+			}
+			for _, spec := range gen.Specs {
+				spec := spec.(*ast.ValueSpec)
+				if len(spec.Names) != len(spec.Values) {
+					continue
+				}
+
+				for i, name := range spec.Names {
+					val := spec.Values[i]
+					if !code.IsCallToAny(pass, val, "errors.New", "fmt.Errorf") {
+						continue
+					}
+
+					if pass.Pkg.Path() == "net/http" && strings.HasPrefix(name.Name, "http2err") {
+						// special case for internal variable names of
+						// bundled HTTP 2 code in net/http
+						continue
+					}
+					prefix := "err"
+					if name.IsExported() {
+						prefix = "Err"
+					}
+					if !strings.HasPrefix(name.Name, prefix) {
+						report.Report(pass, name, fmt.Sprintf("error var %s should have name of the form %sFoo", name.Name, prefix))
+					}
+				}
+			}
+		}
+	}
+	return nil, nil
+}