Validate status codes

redirects.go

@@ -158,5 +158,23 @@ func parseStatus(s string) (code int, err error) {
 	}
 
 	code, err = strconv.Atoi(s)
+	if err != nil {
+		return code, err
+	}
+
+	if !isValidStatusCode(code) {
+		return code, fmt.Errorf("status code %d is not supported", code)
+	}
+
 	return code, err
 }
+
+func isValidStatusCode(status int) bool {
+	validStatuses := []int{200, 301, 302, 303, 307, 308, 404, 410, 451}
+	for _, validStatus := range validStatuses {
+		if validStatus == status {
+			return true
+		}
+	}
+	return false
+}

redirects_test.go

@@ -58,12 +58,22 @@ func TestRule_IsRewrite(t *testing.T) {
 	})
 }
 
-func TestParse(t *testing.T) {
+func Test_Parse(t *testing.T) {
 	t.Run("with illegal force", func(t *testing.T) {
 		_, err := Parse(strings.NewReader(`
 		/home / 301!
 		`))
 
-		assert.Error(t, err, "forced redirects should return an error")
+		assert.Error(t, err)
+		assert.Contains(t, err.Error(), "forced redirects")
+	})
+
+	t.Run("with illegal code", func(t *testing.T) {
+		_, err := Parse(strings.NewReader(`
+		/home / 42
+		`))
+
+		assert.Error(t, err)
+		assert.Contains(t, err.Error(), "status code 42 is not supported")
 	})
 }