Filter.LimitZero

filter.go

@@ -2,7 +2,6 @@ package nostr
 
 import (
 	"encoding/json"
-
 	"slices"
 
 	"github.com/mailru/easyjson"
@@ -19,6 +18,9 @@ type Filter struct {
 	Until   *Timestamp `json:"until,omitempty"`
 	Limit   int        `json:"limit,omitempty"`
 	Search  string     `json:"search,omitempty"`
+
+	// LimitZero is or must be set when there is a "limit":0 in the filter, and not when "limit" is just omitted
+	LimitZero bool `json:"-"`
 }
 
 type TagMap map[string][]string
@@ -115,16 +117,21 @@ func FilterEqual(a Filter, b Filter) bool {
 		return false
 	}
 
+	if a.LimitZero != b.LimitZero {
+		return false
+	}
+
 	return true
 }
 
 func (ef Filter) Clone() Filter {
 	clone := Filter{
-		IDs:     slices.Clone(ef.IDs),
-		Authors: slices.Clone(ef.Authors),
-		Kinds:   slices.Clone(ef.Kinds),
-		Limit:   ef.Limit,
-		Search:  ef.Search,
+		IDs:       slices.Clone(ef.IDs),
+		Authors:   slices.Clone(ef.Authors),
+		Kinds:     slices.Clone(ef.Kinds),
+		Limit:     ef.Limit,
+		Search:    ef.Search,
+		LimitZero: ef.LimitZero,
 	}
 
 	if ef.Tags != nil {

filter_easyjson.go

@@ -129,6 +129,9 @@ func easyjson4d398eaaDecodeGithubComNbdWtfGoNostr(in *jlexer.Lexer, out *Filter)
 			}
 		case "limit":
 			out.Limit = int(in.Int())
+			if out.Limit == 0 {
+				out.LimitZero = true
+			}
 		case "search":
 			out.Search = string(in.String())
 		default:
@@ -243,7 +246,7 @@ func easyjson4d398eaaEncodeGithubComNbdWtfGoNostr(out *jwriter.Writer, in Filter
 		}
 		out.Int64(int64(*in.Until))
 	}
-	if in.Limit != 0 {
+	if in.Limit != 0 || in.LimitZero {
 		const prefix string = ",\"limit\":"
 		if first {
 			first = false

filter_test.go

@@ -2,9 +2,8 @@ package nostr
 
 import (
 	"encoding/json"
-	"testing"
-
 	"slices"
+	"testing"
 )
 
 func TestFilterUnmarshal(t *testing.T) {
@@ -39,6 +38,41 @@ func TestFilterMarshal(t *testing.T) {
 	}
 }
 
+func TestFilterUnmarshalWithLimitZero(t *testing.T) {
+	raw := `{"ids": ["abc"],"#e":["zzz"],"limit":0,"#something":["nothing","bab"],"since":1644254609,"search":"test"}`
+	var f Filter
+	if err := json.Unmarshal([]byte(raw), &f); err != nil {
+		t.Errorf("failed to parse filter json: %v", err)
+	}
+
+	if f.Since == nil ||
+		f.Since.Time().UTC().Format("2006-01-02") != "2022-02-07" ||
+		f.Until != nil ||
+		f.Tags == nil || len(f.Tags) != 2 || !slices.Contains(f.Tags["something"], "bab") ||
+		f.Search != "test" ||
+		f.LimitZero == false {
+		t.Error("failed to parse filter correctly")
+	}
+}
+
+func TestFilterMarshalWithLimitZero(t *testing.T) {
+	until := Timestamp(12345678)
+	filterj, err := json.Marshal(Filter{
+		Kinds:     []int{KindTextNote, KindRecommendServer, KindEncryptedDirectMessage},
+		Tags:      TagMap{"fruit": {"banana", "mango"}},
+		Until:     &until,
+		LimitZero: true,
+	})
+	if err != nil {
+		t.Errorf("failed to marshal filter json: %v", err)
+	}
+
+	expected := `{"kinds":[1,2,4],"until":12345678,"limit":0,"#fruit":["banana","mango"]}`
+	if string(filterj) != expected {
+		t.Errorf("filter json was wrong: %s != %s", string(filterj), expected)
+	}
+}
+
 func TestFilterMatchingLive(t *testing.T) {
 	var filter Filter
 	var event Event