From d4964c845007e2a0ca1dc07dc78876fa39ed3d16 Mon Sep 17 00:00:00 2001
From: Ben Davies <omarshariffdontlikeit@gmail.com>
Date: Thu, 25 Sep 2014 13:27:05 +0100
Subject: [PATCH] Added specific error types rather than generic error types

---
 feed.go | 13 ++++++++++---
 rss.go  |  8 +++++---
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/feed.go b/feed.go
index 8046520..1a03408 100644
--- a/feed.go
+++ b/feed.go
@@ -26,7 +26,6 @@
 package feeder
 
 import (
-	"errors"
 	"fmt"
 	xmlx "github.com/jteeuwen/go-pkg-xmlx"
 	"net/http"
@@ -35,6 +34,15 @@ import (
 	"time"
 )
 
+type UnsupportedFeedError struct {
+	Type    string
+	Version [2]int
+}
+
+func (err *UnsupportedFeedError) Error() string {
+	return fmt.Sprintf("Unsupported feed: %s, version: %+v", err.Type, err.Version)
+}
+
 type ChannelHandler func(f *Feed, newchannels []*Channel)
 type ItemHandler func(f *Feed, ch *Channel, newitems []*Item)
 
@@ -150,8 +158,7 @@ func (this *Feed) makeFeed(doc *xmlx.Document) (err error) {
 	this.Type, this.Version = this.GetVersionInfo(doc)
 
 	if ok := this.testVersions(); !ok {
-		err = errors.New(fmt.Sprintf("Unsupported feed: %s, version: %+v", this.Type, this.Version))
-		return
+		return &UnsupportedFeedError{Type: this.Type, Version: this.Version}
 	}
 
 	if err = this.buildFeed(doc); err != nil || len(this.Channels) == 0 {
diff --git a/rss.go b/rss.go
index 1c347ca..cefec26 100644
--- a/rss.go
+++ b/rss.go
@@ -1,11 +1,13 @@
 package feeder
 
 import (
-	"errors"
-
 	xmlx "github.com/jteeuwen/go-pkg-xmlx"
 )
 
+type MissingRssNodeError struct{}
+
+func (err *MissingRssNodeError) Error() string { return "Failed to find rss/rdf node in XML." }
+
 type Extension struct {
 	Name      string
 	Value     string
@@ -37,7 +39,7 @@ func (this *Feed) readRss2(doc *xmlx.Document) (err error) {
 	}
 
 	if root == nil {
-		return errors.New("Failed to find rss/rdf node in XML.")
+		return &MissingRssNodeError{}
 	}
 
 	channels := root.SelectNodes(ns, "channel")