Don't create tweets from replies (#28)

service/domain/event_note.go

@@ -0,0 +1,19 @@
+package domain
+
+import (
+	"github.com/boreq/errors"
+)
+
+func NoteIsReplyingToOtherEvent(event Event) (bool, error) {
+	if event.Kind() != EventKindNote {
+		return false, errors.New("incorrect event kind")
+	}
+
+	for _, tag := range event.Tags() {
+		if tag.IsEvent() {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}

service/domain/tags.go

@@ -9,6 +9,7 @@ import (
 var (
 	tagProfile = MustNewEventTagName("p")
 	tagRelay   = MustNewEventTagName("r")
+	tagEvent   = MustNewEventTagName("e")
 )
 
 type EventTag struct {
@@ -49,6 +50,10 @@ func (e EventTag) IsRelay() bool {
 	return e.name == tagRelay
 }
 
+func (e EventTag) IsEvent() bool {
+	return e.name == tagEvent
+}
+
 func (e EventTag) Profile() (PublicKey, error) {
 	if !e.IsProfile() {
 		return PublicKey{}, errors.New("not a profile tag")

service/domain/tweet_generator.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"strings"
 	"unicode/utf8"
+
+	"github.com/boreq/errors"
 )
 
 const noteContentMaxLengthInRunes = 200
@@ -20,6 +22,15 @@ func (g *TweetGenerator) Generate(event Event) ([]Tweet, error) {
 		return nil, nil
 	}
 
+	isReply, err := NoteIsReplyingToOtherEvent(event)
+	if err != nil {
+		return nil, errors.Wrap(err, "error checking if note is a reply")
+	}
+
+	if isReply {
+		return nil, nil
+	}
+
 	tweetText := g.createText(event)
 
 	return []Tweet{

service/domain/tweet_generator_test.go

@@ -1,38 +1,78 @@
 package domain_test
 
 import (
+	"fmt"
 	"testing"
 
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/planetary-social/nos-crossposting-service/internal/fixtures"
 	"github.com/planetary-social/nos-crossposting-service/service/domain"
 	"github.com/stretchr/testify/require"
 )
 
-func TestTweetGenerator_GeneratesTweetsFromNotes(t *testing.T) {
-	eventJSON := `{
-  "id": "4376c65d2f232afbe9b882a35baa4f6fe8667c4e684749af565f981833ed6a65",
-  "pubkey": "6e468422dfb74a5738702a8823b9b28168abab8655faacb6853cd0ee15deee93",
-  "created_at": 1673347337,
-  "kind": 1,
-  "content": "Walled gardens became prisons, and nostr is the first step towards tearing down the prison walls.",
-  "tags": [
-    ["e", "3da979448d9ba263864c4d6f14984c423a3838364ec255f03c7904b1ae77f206"],
-    ["p", "bf2376e17ba4ec269d10fcc996a4746b451152be9031fa48e74553dde5526bce"]
-  ],
-  "sig": "908a15e46fb4d8675bab026fc230a0e3542bfade63da02d542fb78b2a8513fcd0092619a2c8c1221e581946e0191f2af505dfdf8657a414dbca329186f009262"
-}`
-
-	event, err := domain.NewEventFromJSON([]byte(eventJSON))
-	require.NoError(t, err)
-
-	g := domain.NewTweetGenerator()
-	tweets, err := g.Generate(event)
-	require.NoError(t, err)
-	require.Equal(t,
-		[]domain.Tweet{
-			domain.NewTweet(
-				"Nostr note made by https://njump.me/npub1dergggklka99wwrs92yz8wdjs952h2ux2ha2ed598ngwu9w7a6fsh9xzpc:\n\nWalled gardens became prisons, and nostr is the first step towards tearing down the prison walls.",
-			),
+func TestTweetGenerator(t *testing.T) {
+	testCases := []struct {
+		Name           string
+		Event          nostr.Event
+		GeneratesTweet bool
+	}{
+		{
+			Name: "not_a_reply",
+			Event: nostr.Event{
+				Kind: domain.EventKindNote.Int(),
+				Tags: []nostr.Tag{
+					[]string{"p", fixtures.SomePublicKey().Hex()},
+				},
+				Content: "Some text.",
+			},
+			GeneratesTweet: true,
 		},
-		tweets,
-	)
+		{
+			Name: "reply",
+			Event: nostr.Event{
+				Kind: domain.EventKindNote.Int(),
+				Tags: []nostr.Tag{
+					[]string{"p", fixtures.SomePublicKey().Hex()},
+					[]string{"e", fixtures.SomeEventID().Hex()},
+				},
+				Content: "Some text.",
+			},
+			GeneratesTweet: false,
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.Name, func(t *testing.T) {
+			libevent := testCase.Event
+
+			authorPublicKey, authorPrivateKey := fixtures.SomeKeyPair()
+
+			err := libevent.Sign(authorPrivateKey)
+			require.NoError(t, err)
+
+			event, err := domain.NewEvent(libevent)
+			require.NoError(t, err)
+
+			g := domain.NewTweetGenerator()
+			tweets, err := g.Generate(event)
+			require.NoError(t, err)
+
+			if testCase.GeneratesTweet {
+				require.Equal(t,
+					[]domain.Tweet{
+						domain.NewTweet(
+							fmt.Sprintf(
+								"Nostr note made by https://njump.me/%s:\n\n%s",
+								authorPublicKey.Npub(),
+								event.Content(),
+							),
+						),
+					},
+					tweets,
+				)
+			} else {
+				require.Empty(t, tweets)
+			}
+		})
+	}
 }