Time parsing.

Rather than just using a string for PubDate, we attempt to parse it.
This includes a couple of crazy non-standard time formats that I've seen
in the wild.

Breaking change: Item.PubDate is no longer a string, it is time.Time.

atom.go

@@ -56,7 +56,7 @@ func (this *Feed) readAtom(doc *xmlx.Document) (err error) {
 			i = new(Item)
 			i.Title = item.S(ns, "title")
 			i.Id = item.S(ns, "id")
-			i.PubDate = item.S(ns, "updated")
+			i.PubDate, _ = parseTime(item.S(ns, "updated"))
 			i.Description = item.S(ns, "summary")
 
 			links := item.SelectNodes(ns, "link")

item.go

@@ -3,6 +3,7 @@ package feeder
 import (
 	"crypto/md5"
 	"io"
+    "time"
 )
 
 type Item struct {
@@ -15,7 +16,7 @@ type Item struct {
 	Comments    string
 	Enclosures  []*Enclosure
 	Guid        *string
-	PubDate     string
+	PubDate     time.Time
 	Source      *Source
 
 	// Atom specific fields
@@ -33,8 +34,8 @@ func (i *Item) Key() string {
 		return *i.Guid
 	case len(i.Id) != 0:
 		return i.Id
-	case len(i.Title) > 0 && len(i.PubDate) > 0:
-		return i.Title + i.PubDate
+	case len(i.Title) > 0 && !i.PubDate.IsZero():
+		return i.Title + i.PubDate.String()
 	default:
 		h := md5.New()
 		io.WriteString(h, i.Description)

rss.go

@@ -162,7 +162,7 @@ func (this *Feed) readRss2(doc *xmlx.Document) (err error) {
 				i.Guid = &guid
 			}
 
-			i.PubDate = item.S(ns, "pubDate")
+			i.PubDate, _ = parseTime(item.S(ns, "pubDate"))
 
 			tl = item.SelectNodes(ns, "category")
 			for _, lv := range tl {

timeparser.go

@@ -0,0 +1,35 @@
+package feeder
+
+import (
+    "strings"
+    "time"
+)
+
+func parseTime(formatted string) (time.Time, error) {
+    var layouts = [...]string{
+        "Mon, _2 Jan 2006 15:04:05 MST",
+        "Mon, _2 Jan 2006 15:04:05 -0700",
+        time.ANSIC,
+        time.UnixDate,
+        time.RubyDate,
+        time.RFC822,
+        time.RFC822Z,
+        time.RFC850,
+        time.RFC1123,
+        time.RFC1123Z,
+        time.RFC3339,
+        time.RFC3339Nano,
+        "Mon, 2, Jan 2006 15:4",
+        "02 Jan 2006 15:04:05 MST",
+    }
+    var t time.Time
+    var err error
+    formatted = strings.TrimSpace(formatted)
+    for _, layout := range layouts {
+        t, err = time.Parse(layout, formatted)
+        if !t.IsZero() {
+            break
+        }
+    }
+    return t, err
+}

timeparser_test.go

@@ -0,0 +1,94 @@
+package feeder
+
+import (
+    "time"
+    "testing"
+)
+
+func Test_InvalidDate(t *testing.T) {
+    date, err := parseTime("invalid")
+    if !date.IsZero() {
+        t.Errorf("Invalid date should parse to zero")
+    }
+    if err == nil {
+        t.Errorf("error should not be nil")
+    }
+}
+
+func Test_ParseLayout0(t *testing.T) {
+    date, err := parseTime("2014-03-07T05:38:00-05:00")
+    expected := time.Date(2014, time.March, 7, 5, 38, 0, 0, time.FixedZone("-0500", -18000))
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout1(t *testing.T) {
+    date, err := parseTime("Fri, 07 Mar 2014 17:42:51 GMT")
+    expected := time.Date(2014, time.March, 7, 17, 42, 51, 0, time.UTC)
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout2(t *testing.T) {
+    date, err := parseTime("2014-02-05T23:33:34Z")
+    expected := time.Date(2014, time.February, 5, 23, 33, 34, 0, time.UTC)
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout3(t *testing.T) {
+    date, err := parseTime("Mon, 03 Mar 2014 02:12:25 +0000")
+    expected := time.Date(2014, time.March, 3, 2, 12, 25, 0, time.UTC)
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout4(t *testing.T) {
+    date, err := parseTime("Fri, 21, Mar 2014 10:41")
+    expected := time.Date(2014, time.March, 21, 10, 41, 0, 0, time.UTC)
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout4_1(t *testing.T) {
+    date, err := parseTime("Fri, 17, Jan 2014 11:1")
+    expected := time.Date(2014, time.January, 17, 11, 1, 0, 0, time.UTC)
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout4_2(t *testing.T) {
+    date, err := parseTime("Thu, 9, Jan 2014 10:19")
+    expected := time.Date(2014, time.January, 9, 10, 19, 0, 0, time.UTC)
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func Test_ParseLayout5(t *testing.T) {
+    date, err := parseTime("22 Jul 2013 14:55:01 EST")
+    expected := time.Date(2013, time.July, 22, 14, 55, 1, 0, time.FixedZone("EST", -18000))
+    assertEqualTime(t, expected, date)
+    if err != nil {
+        t.Errorf("err should be nil")
+    }
+}
+
+func assertEqualTime(t *testing.T, expected, actual time.Time) {
+    if !expected.Equal(actual) {
+        t.Errorf("expected %v but was %v", expected, actual)
+    }
+}