git: introduce type 'FilterProcessStatus'

git/filter_process_status.go

@@ -0,0 +1,33 @@
+package git
+
+import "fmt"
+
+// FilterProcessStatus is a constant type representing the various valid
+// responses for `status=` in the Git filtering process protocol.
+type FilterProcessStatus uint8
+
+const (
+	// StatusSuccess is a valid response when a successful event has
+	// occurred.
+	StatusSuccess FilterProcessStatus = iota + 1
+	// StatusDelay is a valid response when a delay has occurred.
+	StatusDelay
+	// StatusError is a valid response when an error has occurred.
+	StatusError
+)
+
+// String implements fmt.Stringer by returning a protocol-compliant
+// representation of the receiving status, or panic()-ing if the Status is
+// unknown.
+func (s FilterProcessStatus) String() string {
+	switch s {
+	case StatusSuccess:
+		return "success"
+	case StatusDelay:
+		return "delayed"
+	case StatusError:
+		return "error"
+	}
+
+	panic(fmt.Sprintf("git: unknown FilterProcessStatus '%d'", s))
+}