Use errors in protocol

- Rewrite all api's and clients to use the new calls which allows errors
in the responses

cmd/ek/main.go

@@ -173,7 +173,11 @@ Commands:
 	}
 
 	if len(commands) == 1 && commands[0] == "channels" {
-		channels := sub.ChannelsGetList()
+		channels, err := sub.ChannelsGetList()
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
+
 		for _, ch := range channels {
 			fmt.Printf("%-20s %s\n", ch.UID, ch.Name)
 		}
@@ -181,7 +185,10 @@ Commands:
 
 	if len(commands) == 2 && commands[0] == "channels" {
 		name := commands[1]
-		channel := sub.ChannelsCreate(name)
+		channel, err := sub.ChannelsCreate(name)
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
 		fmt.Printf("%s\n", channel.UID)
 	}
 
@@ -189,11 +196,17 @@ Commands:
 		uid := commands[1]
 		if uid == "-delete" {
 			uid = commands[2]
-			sub.ChannelsDelete(uid)
+			err := sub.ChannelsDelete(uid)
+			if err != nil {
+				log.Fatalf("An error occurred: %s\n", err)
+			}
 			fmt.Printf("Channel %s deleted\n", uid)
 		} else {
 			name := commands[2]
-			channel := sub.ChannelsUpdate(uid, name)
+			channel, err := sub.ChannelsUpdate(uid, name)
+			if err != nil {
+				log.Fatalf("An error occurred: %s\n", err)
+			}
 			fmt.Printf("Channel updated %s %s\n", channel.Name, channel.UID)
 		}
 	}
@@ -202,13 +215,18 @@ Commands:
 		channel := commands[1]
 
 		var timeline microsub.Timeline
+		var err error
 
 		if len(commands) == 4 && commands[2] == "-after" {
-			timeline = sub.TimelineGet("", commands[3], channel)
+			timeline, err = sub.TimelineGet("", commands[3], channel)
 		} else if len(commands) == 4 && commands[2] == "-before" {
-			timeline = sub.TimelineGet(commands[3], "", channel)
+			timeline, err = sub.TimelineGet(commands[3], "", channel)
 		} else {
-			timeline = sub.TimelineGet("", "", channel)
+			timeline, err = sub.TimelineGet("", "", channel)
+		}
+
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
 		}
 
 		for _, item := range timeline.Items {
@@ -220,7 +238,10 @@ Commands:
 
 	if len(commands) == 2 && commands[0] == "search" {
 		query := commands[1]
-		feeds := sub.Search(query)
+		feeds, err := sub.Search(query)
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
 
 		for _, feed := range feeds {
 			fmt.Println(feed.Name, " ", feed.URL)
@@ -229,8 +250,11 @@ Commands:
 
 	if len(commands) == 2 && commands[0] == "preview" {
 		url := commands[1]
-		timeline := sub.PreviewURL(url)
+		timeline, err := sub.PreviewURL(url)
 
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
 		for _, item := range timeline.Items {
 			showItem(&item)
 		}
@@ -238,7 +262,10 @@ Commands:
 
 	if len(commands) == 2 && commands[0] == "follow" {
 		uid := commands[1]
-		feeds := sub.FollowGetList(uid)
+		feeds, err := sub.FollowGetList(uid)
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
 		for _, feed := range feeds {
 			fmt.Println(feed.Name, " ", feed.URL)
 		}
@@ -247,13 +274,20 @@ Commands:
 	if len(commands) == 3 && commands[0] == "follow" {
 		uid := commands[1]
 		url := commands[2]
-		sub.FollowURL(uid, url)
+		_, err := sub.FollowURL(uid, url)
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
+		// NOTE(peter): should we show the returned feed here?
 	}
 
 	if len(commands) == 3 && commands[0] == "unfollow" {
 		uid := commands[1]
 		url := commands[2]
-		sub.UnfollowURL(uid, url)
+		err := sub.UnfollowURL(uid, url)
+		if err != nil {
+			log.Fatalf("An error occurred: %s\n", err)
+		}
 	}
 }
 

cmd/eksterd/memory.go

@@ -138,7 +138,7 @@ func createMemoryBackend() microsub.Microsub {
 }
 
 // ChannelsGetList gets channels
-func (b *memoryBackend) ChannelsGetList() []microsub.Channel {
+func (b *memoryBackend) ChannelsGetList() ([]microsub.Channel, error) {
 	conn := pool.Get()
 	defer conn.Close()
 
@@ -156,11 +156,11 @@ func (b *memoryBackend) ChannelsGetList() []microsub.Channel {
 			}
 		}
 	}
-	return channels
+	return channels, nil
 }
 
 // ChannelsCreate creates a channels
-func (b *memoryBackend) ChannelsCreate(name string) microsub.Channel {
+func (b *memoryBackend) ChannelsCreate(name string) (microsub.Channel, error) {
 	defer b.save()
 
 	conn := pool.Get()
@@ -178,22 +178,23 @@ func (b *memoryBackend) ChannelsCreate(name string) microsub.Channel {
 
 	conn.Do("SADD", "channels", uid)
 	conn.Do("SETNX", "channel_sortorder_"+uid, 99999)
-	return channel
+
+	return channel, nil
 }
 
 // ChannelsUpdate updates a channels
-func (b *memoryBackend) ChannelsUpdate(uid, name string) microsub.Channel {
+func (b *memoryBackend) ChannelsUpdate(uid, name string) (microsub.Channel, error) {
 	defer b.save()
 	if c, e := b.Channels[uid]; e {
 		c.Name = name
 		b.Channels[uid] = c
-		return c
+		return c, nil
 	}
-	return microsub.Channel{}
+	return microsub.Channel{}, fmt.Errorf("Channel %s does not exist", uid)
 }
 
 // ChannelsDelete deletes a channel
-func (b *memoryBackend) ChannelsDelete(uid string) {
+func (b *memoryBackend) ChannelsDelete(uid string) error {
 	defer b.save()
 
 	conn := pool.Get()
@@ -204,6 +205,8 @@ func (b *memoryBackend) ChannelsDelete(uid string) {
 
 	delete(b.Channels, uid)
 	delete(b.Feeds, uid)
+
+	return nil
 }
 
 func mapToAuthor(result map[string]string) *microsub.Card {
@@ -391,7 +394,7 @@ func (b *memoryBackend) run() {
 	}()
 }
 
-func (b *memoryBackend) TimelineGet(before, after, channel string) microsub.Timeline {
+func (b *memoryBackend) TimelineGet(before, after, channel string) (microsub.Timeline, error) {
 	conn := pool.Get()
 	defer conn.Close()
 
@@ -430,11 +433,14 @@ func (b *memoryBackend) TimelineGet(before, after, channel string) microsub.Time
 		return microsub.Timeline{
 			Paging: microsub.Pagination{},
 			Items:  items,
-		}
+		}, nil
 	}
 
 	log.Printf("TimelineGet %s\n", channel)
-	feeds := b.FollowGetList(channel)
+	feeds, err := b.FollowGetList(channel)
+	if err != nil {
+		return microsub.Timeline{}, err
+	}
 	log.Println(feeds)
 
 	items := []microsub.Item{}
@@ -476,11 +482,10 @@ func (b *memoryBackend) TimelineGet(before, after, channel string) microsub.Time
 	)
 
 	if err != nil {
-		log.Println(err)
 		return microsub.Timeline{
 			Paging: microsub.Pagination{},
 			Items:  items,
-		}
+		}, err
 	}
 
 	if len(itemScores) >= 2 {
@@ -502,6 +507,7 @@ func (b *memoryBackend) TimelineGet(before, after, channel string) microsub.Time
 		item := microsub.Item{}
 		err := json.Unmarshal(obj, &item)
 		if err != nil {
+			// FIXME: what should we do if one of the items doen't unmarshal?
 			log.Println(err)
 			continue
 		}
@@ -516,7 +522,7 @@ func (b *memoryBackend) TimelineGet(before, after, channel string) microsub.Time
 	return microsub.Timeline{
 		Paging: paging,
 		Items:  items,
-	}
+	}, nil
 }
 
 //panic if s is not a slice
@@ -553,17 +559,17 @@ func reverseSlice(s interface{}) {
 // 	return false
 // }
 
-func (b *memoryBackend) FollowGetList(uid string) []microsub.Feed {
+func (b *memoryBackend) FollowGetList(uid string) ([]microsub.Feed, error) {
-	return b.Feeds[uid]
+	return b.Feeds[uid], nil
 }
 
-func (b *memoryBackend) FollowURL(uid string, url string) microsub.Feed {
+func (b *memoryBackend) FollowURL(uid string, url string) (microsub.Feed, error) {
 	defer b.save()
 	feed := microsub.Feed{Type: "feed", URL: url}
 
 	resp, err := b.Fetch3(uid, feed.URL)
 	if err != nil {
-		return feed
+		return feed, err
 	}
 	defer resp.Body.Close()
 
@@ -571,10 +577,10 @@ func (b *memoryBackend) FollowURL(uid string, url string) microsub.Feed {
 
 	b.ProcessContent(uid, feed.URL, resp.Header.Get("Content-Type"), resp.Body)
 
-	return feed
+	return feed, nil
 }
 
-func (b *memoryBackend) UnfollowURL(uid string, url string) {
+func (b *memoryBackend) UnfollowURL(uid string, url string) error {
 	defer b.save()
 	index := -1
 	for i, f := range b.Feeds[uid] {
@@ -587,6 +593,8 @@ func (b *memoryBackend) UnfollowURL(uid string, url string) {
 		feeds := b.Feeds[uid]
 		b.Feeds[uid] = append(feeds[:index], feeds[index+1:]...)
 	}
+
+	return nil
 }
 
 func checkURL(u string) bool {
@@ -625,7 +633,7 @@ func getPossibleURLs(query string) []string {
 	return urls
 }
 
-func (b *memoryBackend) Search(query string) []microsub.Feed {
+func (b *memoryBackend) Search(query string) ([]microsub.Feed, error) {
 	urls := getPossibleURLs(query)
 
 	feeds := []microsub.Feed{}
@@ -684,27 +692,25 @@ func (b *memoryBackend) Search(query string) []microsub.Feed {
 		}
 	}
 
-	return feeds
+	return feeds, nil
 }
 
-func (b *memoryBackend) PreviewURL(previewURL string) microsub.Timeline {
+func (b *memoryBackend) PreviewURL(previewURL string) (microsub.Timeline, error) {
 	resp, err := Fetch2(previewURL)
 	if err != nil {
-		log.Printf("Error while fetching %s: %v\n", previewURL, err)
+		return microsub.Timeline{}, fmt.Errorf("error while fetching %s: %v", previewURL, err)
-		return microsub.Timeline{}
 	}
 	items, err := b.feedItems(previewURL, resp.Header.Get("content-type"), resp.Body)
 	if err != nil {
-		log.Printf("Error while fetching %s: %v\n", previewURL, err)
+		return microsub.Timeline{}, fmt.Errorf("error while fetching %s: %v", previewURL, err)
-		return microsub.Timeline{}
 	}
 
 	return microsub.Timeline{
 		Items: items,
-	}
+	}, nil
 }
 
-func (b *memoryBackend) MarkRead(channel string, uids []string) {
+func (b *memoryBackend) MarkRead(channel string, uids []string) error {
 	conn := pool.Get()
 	defer conn.Close()
 
@@ -720,6 +726,7 @@ func (b *memoryBackend) MarkRead(channel string, uids []string) {
 
 	if _, err := conn.Do("SADD", args...); err != nil {
 		log.Printf("Marking read for channel %s has failed\n", channel)
+		return err
 	}
 
 	zchannelKey := fmt.Sprintf("zchannel:%s:posts", channel)
@@ -727,6 +734,7 @@ func (b *memoryBackend) MarkRead(channel string, uids []string) {
 
 	if _, err := conn.Do("ZREM", args...); err != nil {
 		log.Printf("Marking read for channel %s has failed\n", channel)
+		return err
 	}
 
 	unread, _ := redis.Int(conn.Do("ZCARD", zchannelKey))
@@ -741,4 +749,6 @@ func (b *memoryBackend) MarkRead(channel string, uids []string) {
 	}
 
 	log.Printf("Marking read success for %s %v\n", channel, itemUIDs)
+
+	return nil
 }

cmd/eksterd/microsub.go

@@ -49,34 +49,67 @@ func (h *microsubHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		values := r.URL.Query()
 		action := values.Get("action")
 		if action == "channels" {
-			channels := h.Backend.ChannelsGetList()
+			channels, err := h.Backend.ChannelsGetList()
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			jw := json.NewEncoder(w)
 			w.Header().Add("Content-Type", "application/json")
-			jw.Encode(map[string][]microsub.Channel{
+			err = jw.Encode(map[string][]microsub.Channel{
 				"channels": channels,
 			})
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 		} else if action == "timeline" {
-			timeline := h.Backend.TimelineGet(values.Get("before"), values.Get("after"), values.Get("channel"))
+			timeline, err := h.Backend.TimelineGet(values.Get("before"), values.Get("after"), values.Get("channel"))
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			jw := json.NewEncoder(w)
 			w.Header().Add("Content-Type", "application/json")
 			jw.SetIndent("", "    ")
-			jw.Encode(timeline)
+			err = jw.Encode(timeline)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 		} else if action == "preview" {
-			timeline := h.Backend.PreviewURL(values.Get("url"))
+			timeline, err := h.Backend.PreviewURL(values.Get("url"))
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			jw := json.NewEncoder(w)
 			jw.SetIndent("", "    ")
 			w.Header().Add("Content-Type", "application/json")
-			jw.Encode(timeline)
+			err = jw.Encode(timeline)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 		} else if action == "follow" {
 			channel := values.Get("channel")
-			following := h.Backend.FollowGetList(channel)
+			following, err := h.Backend.FollowGetList(channel)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			jw := json.NewEncoder(w)
 			w.Header().Add("Content-Type", "application/json")
-			jw.Encode(map[string][]microsub.Feed{
+			err = jw.Encode(map[string][]microsub.Feed{
 				"items": following,
 			})
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 		} else {
-			log.Printf("unknown action %s\n", action)
+			http.Error(w, fmt.Sprintf("unknown action %s\n", action), 500)
+			return
 		}
 		return
 	} else if r.Method == http.MethodPost {
@@ -87,7 +120,11 @@ func (h *microsubHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			method := values.Get("method")
 			uid := values.Get("channel")
 			if method == "delete" {
-				h.Backend.ChannelsDelete(uid)
+				err := h.Backend.ChannelsDelete(uid)
+				if err != nil {
+					http.Error(w, err.Error(), 500)
+					return
+				}
 				w.Header().Add("Content-Type", "application/json")
 				fmt.Fprintln(w, "[]")
 				h.Backend.(Debug).Debug()
@@ -96,37 +133,73 @@ func (h *microsubHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 			jw := json.NewEncoder(w)
 			if uid == "" {
-				channel := h.Backend.ChannelsCreate(name)
+				channel, err := h.Backend.ChannelsCreate(name)
+				if err != nil {
+					http.Error(w, err.Error(), 500)
+					return
+				}
 				w.Header().Add("Content-Type", "application/json")
-				jw.Encode(channel)
+				err = jw.Encode(channel)
+				if err != nil {
+					http.Error(w, err.Error(), 500)
+					return
+				}
 			} else {
-				channel := h.Backend.ChannelsUpdate(uid, name)
+				channel, err := h.Backend.ChannelsUpdate(uid, name)
+				if err != nil {
+					http.Error(w, err.Error(), 500)
+					return
+				}
 				w.Header().Add("Content-Type", "application/json")
-				jw.Encode(channel)
+				err = jw.Encode(channel)
+				if err != nil {
+					http.Error(w, err.Error(), 500)
+					return
+				}
 			}
 			h.Backend.(Debug).Debug()
 		} else if action == "follow" {
 			uid := values.Get("channel")
 			url := values.Get("url")
 			h.HubIncomingBackend.CreateFeed(url, uid)
-			feed := h.Backend.FollowURL(uid, url)
+			feed, err := h.Backend.FollowURL(uid, url)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			w.Header().Add("Content-Type", "application/json")
 			jw := json.NewEncoder(w)
-			jw.Encode(feed)
+			err = jw.Encode(feed)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 		} else if action == "unfollow" {
 			uid := values.Get("channel")
 			url := values.Get("url")
-			h.Backend.UnfollowURL(uid, url)
+			err := h.Backend.UnfollowURL(uid, url)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			w.Header().Add("Content-Type", "application/json")
 			fmt.Fprintln(w, "[]")
 		} else if action == "search" {
 			query := values.Get("query")
-			feeds := h.Backend.Search(query)
+			feeds, err := h.Backend.Search(query)
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 			jw := json.NewEncoder(w)
 			w.Header().Add("Content-Type", "application/json")
-			jw.Encode(map[string][]microsub.Feed{
+			err = jw.Encode(map[string][]microsub.Feed{
 				"results": feeds,
 			})
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+				return
+			}
 		} else if action == "timeline" || r.PostForm.Get("action") == "timeline" {
 			method := values.Get("method")
 
@@ -134,9 +207,17 @@ func (h *microsubHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				values = r.Form
 				channel := values.Get("channel")
 				if uids, e := values["entry"]; e {
-					h.Backend.MarkRead(channel, uids)
+					err := h.Backend.MarkRead(channel, uids)
+					if err != nil {
+						http.Error(w, err.Error(), 500)
+						return
+					}
 				} else if uids, e := values["entry[]"]; e {
-					h.Backend.MarkRead(channel, uids)
+					err := h.Backend.MarkRead(channel, uids)
+					if err != nil {
+						http.Error(w, err.Error(), 500)
+						return
+					}
 				} else {
 					uids := []string{}
 					for k, v := range values {
@@ -144,15 +225,20 @@ func (h *microsubHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 							uids = append(uids, v...)
 						}
 					}
-					h.Backend.MarkRead(channel, uids)
+					err := h.Backend.MarkRead(channel, uids)
+					if err != nil {
+						http.Error(w, err.Error(), 500)
+						return
+					}
 				}
 			} else {
-				log.Printf("unknown method in timeline %s\n", method)
+				http.Error(w, fmt.Sprintf("unknown method in timeline %s\n", method), 500)
+				return
 			}
 			w.Header().Add("Content-Type", "application/json")
 			fmt.Fprintln(w, "[]")
 		} else {
-			log.Printf("unknown action %s\n", action)
+			http.Error(w, fmt.Sprintf("unknown action %s\n", action), 500)
 		}
 
 		return

cmd/eksterd/null.go

@@ -26,64 +26,67 @@ type NullBackend struct {
 }
 
 // ChannelsGetList gets no channels
-func (b *NullBackend) ChannelsGetList() []microsub.Channel {
+func (b *NullBackend) ChannelsGetList() ([]microsub.Channel, error) {
 	return []microsub.Channel{
 		microsub.Channel{UID: "0000", Name: "default", Unread: 0},
 		microsub.Channel{UID: "0001", Name: "notifications", Unread: 0},
 		microsub.Channel{UID: "1000", Name: "Friends", Unread: 0},
 		microsub.Channel{UID: "1001", Name: "Family", Unread: 0},
-	}
+	}, nil
 }
 
 // ChannelsCreate creates no channels
-func (b *NullBackend) ChannelsCreate(name string) microsub.Channel {
+func (b *NullBackend) ChannelsCreate(name string) (microsub.Channel, error) {
 	return microsub.Channel{
 		UID:  "1234",
 		Name: name,
-	}
+	}, nil
 }
 
 // ChannelsUpdate updates no channels
-func (b *NullBackend) ChannelsUpdate(uid, name string) microsub.Channel {
+func (b *NullBackend) ChannelsUpdate(uid, name string) (microsub.Channel, error) {
 	return microsub.Channel{
 		UID:  uid,
 		Name: name,
-	}
+	}, nil
 }
 
 // ChannelsDelete delets no channels
-func (b *NullBackend) ChannelsDelete(uid string) {
+func (b *NullBackend) ChannelsDelete(uid string) error {
+	return nil
 }
 
 // TimelineGet gets no timeline
-func (b *NullBackend) TimelineGet(before, after, channel string) microsub.Timeline {
+func (b *NullBackend) TimelineGet(before, after, channel string) (microsub.Timeline, error) {
 	return microsub.Timeline{
 		Paging: microsub.Pagination{},
 		Items:  []microsub.Item{},
-	}
+	}, nil
 }
 
-func (b *NullBackend) FollowGetList(uid string) []microsub.Feed {
+func (b *NullBackend) FollowGetList(uid string) ([]microsub.Feed, error) {
-	return []microsub.Feed{}
+	return []microsub.Feed{}, nil
 }
 
-func (b *NullBackend) FollowURL(uid string, url string) microsub.Feed {
+func (b *NullBackend) FollowURL(uid string, url string) (microsub.Feed, error) {
-	return microsub.Feed{Type: "feed", URL: url}
+	return microsub.Feed{Type: "feed", URL: url}, nil
 }
 
-func (b *NullBackend) UnfollowURL(uid string, url string) {
+func (b *NullBackend) UnfollowURL(uid string, url string) error {
+	return nil
 }
 
-func (b *NullBackend) Search(query string) []microsub.Feed {
+func (b *NullBackend) Search(query string) ([]microsub.Feed, error) {
-	return []microsub.Feed{}
+	return []microsub.Feed{}, nil
 }
 
-func (b *NullBackend) PreviewURL(url string) microsub.Timeline {
+func (b *NullBackend) PreviewURL(url string) (microsub.Timeline, error) {
 	return microsub.Timeline{
 		Paging: microsub.Pagination{},
 		Items:  []microsub.Item{},
-	}
+	}, nil
 }
 
-func (b *NullBackend) MarkRead(channel string, uids []string) {
+func (b *NullBackend) MarkRead(channel string, uids []string) error {
+	return nil
 }

pkg/client/requests.go

@@ -3,7 +3,6 @@ package client
 import (
 	"encoding/json"
 	"fmt"
-	"log"
 	"net/http"
 	"net/url"
 	"strings"
@@ -80,12 +79,11 @@ func (c *Client) microsubPostFormRequest(action string, args map[string]string,
 	return client.Do(req)
 }
 
-func (c *Client) ChannelsGetList() []microsub.Channel {
+func (c *Client) ChannelsGetList() ([]microsub.Channel, error) {
 	args := make(map[string]string)
 	res, err := c.microsubGetRequest("channels", args)
 	if err != nil {
-		log.Println(err)
+		return []microsub.Channel{}, err
-		return []microsub.Channel{}
 	}
 	defer res.Body.Close()
 
@@ -95,52 +93,56 @@ func (c *Client) ChannelsGetList() []microsub.Channel {
 
 	dec := json.NewDecoder(res.Body)
 	var channels channelsResponse
-	dec.Decode(&channels)
+	err = dec.Decode(&channels)
-	return channels.Channels
+	if err != nil {
+		return channels.Channels, err
+	}
+
+	return channels.Channels, nil
 }
 
-func (c *Client) TimelineGet(before, after, channel string) microsub.Timeline {
+func (c *Client) TimelineGet(before, after, channel string) (microsub.Timeline, error) {
 	args := make(map[string]string)
 	args["after"] = after
 	args["before"] = before
 	args["channel"] = channel
 	res, err := c.microsubGetRequest("timeline", args)
 	if err != nil {
-		log.Println(err)
+		return microsub.Timeline{}, err
-		return microsub.Timeline{}
 	}
 	defer res.Body.Close()
 	dec := json.NewDecoder(res.Body)
 	var timeline microsub.Timeline
 	err = dec.Decode(&timeline)
 	if err != nil {
-		log.Fatal(err)
+		return microsub.Timeline{}, err
 	}
-	return timeline
+	return timeline, nil
 }
 
-func (c *Client) PreviewURL(url string) microsub.Timeline {
+func (c *Client) PreviewURL(url string) (microsub.Timeline, error) {
 	args := make(map[string]string)
 	args["url"] = url
 	res, err := c.microsubGetRequest("preview", args)
 	if err != nil {
-		log.Println(err)
+		return microsub.Timeline{}, err
-		return microsub.Timeline{}
 	}
 	defer res.Body.Close()
 	dec := json.NewDecoder(res.Body)
 	var timeline microsub.Timeline
-	dec.Decode(&timeline)
+	err = dec.Decode(&timeline)
-	return timeline
+	if err != nil {
+		return microsub.Timeline{}, err
+	}
+	return timeline, nil
 }
 
-func (c *Client) FollowGetList(channel string) []microsub.Feed {
+func (c *Client) FollowGetList(channel string) ([]microsub.Feed, error) {
 	args := make(map[string]string)
 	args["channel"] = channel
 	res, err := c.microsubGetRequest("follow", args)
 	if err != nil {
-		log.Println(err)
+		return []microsub.Feed{}, nil
-		return []microsub.Feed{}
 	}
 	defer res.Body.Close()
 	dec := json.NewDecoder(res.Body)
@@ -148,88 +150,96 @@ func (c *Client) FollowGetList(channel string) []microsub.Feed {
 		Items []microsub.Feed `json:"items"`
 	}
 	var response followResponse
-	dec.Decode(&response)
+	err = dec.Decode(&response)
-	return response.Items
+	if err != nil {
+		return []microsub.Feed{}, nil
+	}
+	return response.Items, nil
 }
 
-func (c *Client) ChannelsCreate(name string) microsub.Channel {
+func (c *Client) ChannelsCreate(name string) (microsub.Channel, error) {
 	args := make(map[string]string)
 	args["name"] = name
 	res, err := c.microsubPostRequest("channels", args)
 	if err != nil {
-		log.Println(err)
+		return microsub.Channel{}, nil
-		return microsub.Channel{}
 	}
 	defer res.Body.Close()
 	var channel microsub.Channel
 	dec := json.NewDecoder(res.Body)
-	dec.Decode(&channel)
+	err = dec.Decode(&channel)
-	return channel
+	if err != nil {
+		return microsub.Channel{}, nil
+	}
+	return channel, nil
 }
 
-func (c *Client) ChannelsUpdate(uid, name string) microsub.Channel {
+func (c *Client) ChannelsUpdate(uid, name string) (microsub.Channel, error) {
 	args := make(map[string]string)
 	args["name"] = name
 	args["uid"] = uid
 	res, err := c.microsubPostRequest("channels", args)
 	if err != nil {
-		log.Println(err)
+		return microsub.Channel{}, err
-		return microsub.Channel{}
 	}
 	defer res.Body.Close()
 	var channel microsub.Channel
 	dec := json.NewDecoder(res.Body)
-	dec.Decode(&channel)
+	err = dec.Decode(&channel)
-	return channel
+	if err != nil {
+		return microsub.Channel{}, err
+	}
+	return channel, nil
 }
 
-func (c *Client) ChannelsDelete(uid string) {
+func (c *Client) ChannelsDelete(uid string) error {
 	args := make(map[string]string)
 	args["channel"] = uid
 	args["method"] = "delete"
 	res, err := c.microsubPostRequest("channels", args)
 	if err != nil {
-		log.Println(err)
+		return err
-		return
 	}
 	res.Body.Close()
+	return nil
 }
 
-func (c *Client) FollowURL(channel, url string) microsub.Feed {
+func (c *Client) FollowURL(channel, url string) (microsub.Feed, error) {
 	args := make(map[string]string)
 	args["channel"] = channel
 	args["url"] = url
 	res, err := c.microsubPostRequest("follow", args)
 	if err != nil {
-		log.Println(err)
+		return microsub.Feed{}, err
-		return microsub.Feed{}
 	}
 	defer res.Body.Close()
 	var feed microsub.Feed
 	dec := json.NewDecoder(res.Body)
-	dec.Decode(&feed)
+	err = dec.Decode(&feed)
-	return feed
+	if err != nil {
+		return microsub.Feed{}, err
+	}
+	return feed, nil
 }
 
-func (c *Client) UnfollowURL(channel, url string) {
+func (c *Client) UnfollowURL(channel, url string) error {
 	args := make(map[string]string)
 	args["channel"] = channel
 	args["url"] = url
 	res, err := c.microsubPostRequest("unfollow", args)
 	if err != nil {
-		log.Println(err)
+		return err
-		return
 	}
 	res.Body.Close()
+	return nil
 }
 
-func (c *Client) Search(query string) []microsub.Feed {
+func (c *Client) Search(query string) ([]microsub.Feed, error) {
 	args := make(map[string]string)
 	args["query"] = query
 	res, err := c.microsubPostRequest("search", args)
 	if err != nil {
-		log.Println(err)
+		return []microsub.Feed{}, err
-		return []microsub.Feed{}
 	}
 	type searchResponse struct {
 		Results []microsub.Feed `json:"results"`
@@ -237,11 +247,14 @@ func (c *Client) Search(query string) []microsub.Feed {
 	defer res.Body.Close()
 	var response searchResponse
 	dec := json.NewDecoder(res.Body)
-	dec.Decode(&response)
+	err = dec.Decode(&response)
-	return response.Results
+	if err != nil {
+		return []microsub.Feed{}, err
+	}
+	return response.Results, nil
 }
 
-func (c *Client) MarkRead(channel string, uids []string) {
+func (c *Client) MarkRead(channel string, uids []string) error {
 	args := make(map[string]string)
 	args["channel"] = channel
 
@@ -251,7 +264,9 @@ func (c *Client) MarkRead(channel string, uids []string) {
 	}
 
 	res, err := c.microsubPostFormRequest("mark_read", args, data)
-	if err == nil {
+	if err != nil {
-		defer res.Body.Close()
+		return err
 	}
+	res.Body.Close()
+	return nil
 }

pkg/microsub/protocol.go

@@ -102,20 +102,20 @@ type Feed struct {
 
 // Microsub is the main protocol that should be implemented by a backend
 type Microsub interface {
-	ChannelsGetList() []Channel
+	ChannelsGetList() ([]Channel, error)
-	ChannelsCreate(name string) Channel
+	ChannelsCreate(name string) (Channel, error)
-	ChannelsUpdate(uid, name string) Channel
+	ChannelsUpdate(uid, name string) (Channel, error)
-	ChannelsDelete(uid string)
+	ChannelsDelete(uid string) error
 
-	TimelineGet(before, after, channel string) Timeline
+	TimelineGet(before, after, channel string) (Timeline, error)
 
-	MarkRead(channel string, entry []string)
+	MarkRead(channel string, entry []string) error
 
-	FollowGetList(uid string) []Feed
+	FollowGetList(uid string) ([]Feed, error)
-	FollowURL(uid string, url string) Feed
+	FollowURL(uid string, url string) (Feed, error)
 
-	UnfollowURL(uid string, url string)
+	UnfollowURL(uid string, url string) error
 
-	Search(query string) []Feed
+	Search(query string) ([]Feed, error)
-	PreviewURL(url string) Timeline
+	PreviewURL(url string) (Timeline, error)
 }