1 files changed, 48 insertions, 0 deletions
diff --git a/tools/golangci-lint/gitaly/unavailable_code.go b/tools/golangci-lint/gitaly/unavailable_code.go
new file mode 100644
index 000000000..9546b1871
--- /dev/null
+++ b/tools/golangci-lint/gitaly/unavailable_code.go
@@ -0,0 +1,48 @@
+package main
+
+import (
+	"go/ast"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+const unavailableCodeAnalyzerName = "unavailable_code"
+
+type unavailableCodeAnalyzerSettings struct {
+	IncludedFunctions []string `mapstructure:"included-functions"`
+}
+
+// newErrorWrapAnalyzer warns if Unavailable status code is used. Unavailable status code is reserved to signal server's
+// unavailability. It should be used by some specific components. gRPC handlers should typically avoid this type of
+// error.
+// For more information:
+// https://gitlab.com/gitlab-org/gitaly/-/blob/master/STYLE.md?plain=0#unavailable-code
+func newUnavailableCodeAnalyzer(settings *unavailableCodeAnalyzerSettings) *analysis.Analyzer {
+	return &analysis.Analyzer{
+		Name: unavailableCodeAnalyzerName,
+		Doc:  `discourage the usage of Unavailable status code`,
+		Run:  runUnavailableCodeAnalyzer(settings.IncludedFunctions),
+	}
+}
+
+func runUnavailableCodeAnalyzer(rules []string) func(*analysis.Pass) (interface{}, error) {
+	return func(pass *analysis.Pass) (interface{}, error) {
+		matcher := NewMatcher(pass)
+		for _, file := range pass.Files {
+			ast.Inspect(file, func(n ast.Node) bool {
+				if call, ok := n.(*ast.CallExpr); ok {
+					if matcher.MatchFunction(call, rules) {
+						pass.Report(analysis.Diagnostic{
+							Pos:            call.Pos(),
+							End:            call.End(),
+							Message:        "please avoid using the Unavailable status code: https://gitlab.com/gitlab-org/gitaly/-/blob/master/STYLE.md?plain=0#unavailable-code",
+							SuggestedFixes: nil,
+						})
+					}
+				}
+				return true
+			})
+		}
+		return nil, nil
+	}
+}