merged with fixes

internal/store/postgres/message_search_count_test.go

@@ -0,0 +1,56 @@
+package postgres
+
+import (
+	"context"
+	"errors"
+	"github.com/jackc/pgx/v5"
+	"strings"
+	"telesrv/internal/domain"
+	"testing"
+)
+
+// A DB boundary that only accepts the count query. Embedded unexpected methods
+// panic, so a page fetch, enrichment query or mutation cannot pass this test.
+type countReadDB struct {
+	pgx.Tx
+	calls  int
+	result int32
+	err    error
+}
+
+func (d *countReadDB) QueryRow(_ context.Context, q string, args ...any) pgx.Row {
+	if !strings.HasPrefix(q, "-- name: CountMessagesByUser :one") {
+		panic("unexpected query")
+	}
+	d.calls++
+	return countReadRow{d.result, d.err}
+}
+
+type countReadRow struct {
+	value int32
+	err   error
+}
+
+func (r countReadRow) Scan(dest ...any) error {
+	if r.err != nil {
+		return r.err
+	}
+	*dest[0].(*int32) = r.value
+	return nil
+}
+func TestMessageSearchCountOnlySkipsPageAndHydration(t *testing.T) {
+	for _, count := range []int32{0, 7} {
+		db := &countReadDB{result: count}
+		s := NewMessageStore(db)
+		got, err := s.ListByUser(context.Background(), 1, domain.MessageFilter{CountOnly: true, SenderUserID: 2, OffsetID: 8, AddOffset: -3, Limit: 500})
+		if err != nil || got.Count != int(count) || len(got.Messages) != 0 || len(got.Users) != 0 || db.calls != 1 {
+			t.Fatalf("result=%+v err=%v calls=%d", got, err, db.calls)
+		}
+	}
+	failure := errors.New("database unavailable")
+	db := &countReadDB{err: failure}
+	got, err := NewMessageStore(db).ListByUser(context.Background(), 1, domain.MessageFilter{CountOnly: true})
+	if !errors.Is(err, failure) || got.Count != 0 || db.calls != 1 {
+		t.Fatalf("error swallowed: result=%+v err=%v", got, err)
+	}
+}