add removeFeed to remove feed from channels

cmd/eksterd/memory.go

@@ -290,6 +290,21 @@ func (b *memoryBackend) ChannelsDelete(uid string) error {
 	return nil
 }
 
+func (b *memoryBackend) removeFeed(feedID string) error {
+	b.lock.Lock()
+	for uid := range b.Channels {
+		feeds := b.Feeds[uid]
+		for i, feed := range feeds {
+			if feed.URL == feedID {
+				feeds = append(feeds[:i], feeds[i+1:]...)
+			}
+		}
+		b.Feeds[uid] = feeds
+	}
+	b.lock.Unlock()
+	return nil
+}
+
 func (b *memoryBackend) getFeeds() map[string][]string {
 	feeds := make(map[string][]string)
 	b.lock.RLock()

cmd/eksterd/memory_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/gomodule/redigo/redis"
+	"github.com/stretchr/testify/assert"
 	"p83.nl/go/ekster/pkg/microsub"
 	"p83.nl/go/ekster/pkg/sse"
 )
@@ -112,3 +113,110 @@ func Test_memoryBackend_ChannelsCreate(t *testing.T) {
 		})
 	}
 }
+
+func Test_memoryBackend_removeFeed(t *testing.T) {
+	type fields struct {
+		Channels map[string]microsub.Channel
+		Feeds    map[string][]microsub.Feed
+	}
+	type args struct {
+		feedID string
+	}
+	tests := []struct {
+		name    string
+		fields  fields
+		args    args
+		lens    map[string]int
+		wantErr bool
+	}{
+		{
+			name: "remove from channel 1",
+			fields: fields{
+				Channels: map[string]microsub.Channel{
+					"123": {UID: "channel1", Name: "Channel 1"},
+					"124": {UID: "channel2", Name: "Channel 2"},
+				},
+				Feeds: map[string][]microsub.Feed{
+					"123": {{Type: "feed", URL: "feed1", Name: "Feed1"}},
+					"124": {{Type: "feed", URL: "feed2", Name: "Feed2"}},
+				},
+			},
+			args:    args{feedID: "feed1"},
+			lens:    map[string]int{"123": 0, "124": 1},
+			wantErr: false,
+		},
+		{
+			name: "remove from channel 2",
+			fields: fields{
+				Channels: map[string]microsub.Channel{
+					"123": {UID: "channel1", Name: "Channel 1"},
+					"124": {UID: "channel2", Name: "Channel 2"},
+				},
+				Feeds: map[string][]microsub.Feed{
+					"123": {{Type: "feed", URL: "feed1", Name: "Feed1"}},
+					"124": {{Type: "feed", URL: "feed2", Name: "Feed2"}},
+				},
+			},
+			args:    args{feedID: "feed2"},
+			lens:    map[string]int{"123": 1, "124": 0},
+			wantErr: false,
+		},
+		{
+			name: "remove unknown",
+			fields: fields{
+				Channels: map[string]microsub.Channel{
+					"123": {UID: "channel1", Name: "Channel 1"},
+					"124": {UID: "channel2", Name: "Channel 2"},
+				},
+				Feeds: map[string][]microsub.Feed{
+					"123": {{Type: "feed", URL: "feed1", Name: "Feed1"}},
+					"124": {{Type: "feed", URL: "feed2", Name: "Feed2"}},
+				},
+			},
+			args:    args{feedID: "feed3"},
+			lens:    map[string]int{"123": 1, "124": 1},
+			wantErr: false,
+		},
+		{
+			name: "remove from 0 channels",
+			fields: fields{
+				Channels: map[string]microsub.Channel{},
+				Feeds:    map[string][]microsub.Feed{},
+			},
+			args:    args{feedID: "feed3"},
+			lens:    map[string]int{},
+			wantErr: false,
+		},
+		{
+			name: "remove from multiple channels",
+			fields: fields{
+				Channels: map[string]microsub.Channel{
+					"123": {UID: "channel1", Name: "Channel 1"},
+					"124": {UID: "channel2", Name: "Channel 2"},
+				},
+				Feeds: map[string][]microsub.Feed{
+					"123": {{Type: "feed", URL: "feed1", Name: "Feed1"}},
+					"124": {{Type: "feed", URL: "feed1", Name: "Feed1"}},
+				},
+			},
+			args:    args{feedID: "feed1"},
+			lens:    map[string]int{"123": 0, "124": 0},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			b := &memoryBackend{
+				Channels: tt.fields.Channels,
+				Feeds:    tt.fields.Feeds,
+			}
+			if err := b.removeFeed(tt.args.feedID); (err != nil) != tt.wantErr {
+				t.Errorf("removeFeed() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			assert.Len(t, b.Channels, len(tt.lens))
+			for k, v := range tt.lens {
+				assert.Len(t, b.Feeds[k], v)
+			}
+		})
+	}
+}