From e7f5fb0831f3ea8216a297bcf52268075c4947cb Mon Sep 17 00:00:00 2001
From: "Bora M. Alper" <bora@boramalper.org>
Date: Sun, 30 Dec 2018 08:24:33 +0300
Subject: [PATCH] better error handling at iso8601

---
 pkg/persistence/iso8601.go | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/pkg/persistence/iso8601.go b/pkg/persistence/iso8601.go
index e43f428..597b9e7 100644
--- a/pkg/persistence/iso8601.go
+++ b/pkg/persistence/iso8601.go
@@ -31,32 +31,44 @@ func ParseISO8601(s string) (*time.Time, Granularity, error) {
 		if err != nil {
 			return nil, -1, err
 		}
+
 		t := time.Date(year, time.December, daysOfMonth(time.December, year), 23, 59, 59, 0, time.UTC)
 		return &t, Year, nil
 	}
 
 	if matches := monthRE.FindStringSubmatch(s); len(matches) != 0 {
 		month, err := parseMonth(matches[2])
+		if err != nil {
+			return nil, -1, err
+		}
 		year, err := parseYear(matches[1])
 		if err != nil {
 			return nil, -1, err
 		}
+
 		t := time.Date(year, month, 31, 23, 59, 59, 0, time.UTC)
 		return &t, Month, nil
 	}
 
 	if matches := weekRE.FindStringSubmatch(s); len(matches) != 0 {
 		week, err := parseWeek(matches[2])
+		if err != nil {
+			return nil, -1, err
+		}
 		year, err := parseYear(matches[1])
 		if err != nil {
 			return nil, -1, err
 		}
+
 		t := time.Date(year, time.January, week*7, 23, 59, 59, 0, time.UTC)
 		return &t, Week, nil
 	}
 
 	if matches := dayRE.FindStringSubmatch(s); len(matches) != 0 {
 		month, err := parseMonth(matches[2])
+		if err != nil {
+			return nil, -1, err
+		}
 		year, err := parseYear(matches[1])
 		if err != nil {
 			return nil, -1, err
@@ -65,21 +77,29 @@ func ParseISO8601(s string) (*time.Time, Granularity, error) {
 		if err != nil {
 			return nil, -1, err
 		}
+
 		t := time.Date(year, month, day, 23, 59, 59, 0, time.UTC)
 		return &t, Day, nil
 	}
 
 	if matches := hourRE.FindStringSubmatch(s); len(matches) != 0 {
 		month, err := parseMonth(matches[2])
+		if err != nil {
+			return nil, -1, err
+		}
 		year, err := parseYear(matches[1])
 		if err != nil {
 			return nil, -1, err
 		}
 		hour, err := parseHour(matches[4])
+		if err != nil {
+			return nil, -1, err
+		}
 		day, err := parseDay(matches[3], daysOfMonth(month, year))
 		if err != nil {
 			return nil, -1, err
 		}
+
 		t := time.Date(year, month, day, hour, 59, 59, 0, time.UTC)
 		return &t, Hour, nil
 	}