feat: add episode service merge and broadcast tests

internal/episodes/service/service_test.go

@@ -0,0 +1,69 @@
+package service
+
+import (
+	"mal/integrations/jikan"
+	"mal/internal/domain"
+	"testing"
+	"time"
+)
+
+func TestMergeEpisodesUsesUnionAndSynthesizesProviderOnlyEntries(t *testing.T) {
+	episodes := mergeEpisodes([]jikan.Episode{
+		{MalID: 1, Title: "Start"},
+		{MalID: 2, Title: "Second", Filler: true},
+		{MalID: 5, Title: "Future", Recap: true},
+	}, domain.EpisodeAvailability{
+		Sub: []int{1, 2, 3, 6},
+		Dub: []int{1, 2, 3},
+	})
+
+	if len(episodes) != 5 {
+		t.Fatalf("len(episodes) = %d, want 5", len(episodes))
+	}
+
+	assertEpisode(t, episodes[0], 1, "Start", true, true, false, false, false)
+	assertEpisode(t, episodes[1], 2, "Second", true, true, false, true, false)
+	assertEpisode(t, episodes[2], 3, "Episode 3", true, true, false, false, false)
+	assertEpisode(t, episodes[3], 5, "Future", false, false, false, false, true)
+	assertEpisode(t, episodes[4], 6, "Episode 6", true, false, true, false, false)
+}
+
+func TestNextBroadcastAfterUsesJikanTimezone(t *testing.T) {
+	anime := domain.Anime{MalID: 1}
+	anime.Broadcast.Day = "Saturdays"
+	anime.Broadcast.Time = "23:00"
+	anime.Broadcast.Timezone = "Asia/Tokyo"
+
+	after := time.Date(2026, 5, 15, 12, 0, 0, 0, time.UTC)
+	got := nextBroadcastAfter(anime, after)
+	want := time.Date(2026, 5, 16, 14, 0, 0, 0, time.UTC)
+
+	if !got.Equal(want) {
+		t.Fatalf("nextBroadcastAfter() = %s, want %s", got, want)
+	}
+}
+
+func TestNextRetryTimeWithinAndAfterRetryWindow(t *testing.T) {
+	anime := domain.Anime{MalID: 1}
+	anime.Broadcast.Day = "Saturdays"
+	anime.Broadcast.Time = "12:00"
+	anime.Broadcast.Timezone = "UTC"
+
+	within := time.Date(2026, 5, 16, 13, 0, 0, 0, time.UTC)
+	if got := nextRetryTime(anime, within); !got.Equal(within.Add(retryInterval)) {
+		t.Fatalf("nextRetryTime(within) = %s, want %s", got, within.Add(retryInterval))
+	}
+
+	after := time.Date(2026, 5, 16, 16, 1, 0, 0, time.UTC)
+	want := time.Date(2026, 5, 23, 12, 0, 0, 0, time.UTC)
+	if got := nextRetryTime(anime, after); !got.Equal(want) {
+		t.Fatalf("nextRetryTime(after) = %s, want %s", got, want)
+	}
+}
+
+func assertEpisode(t *testing.T, got domain.CanonicalEpisode, number int, title string, sub bool, dub bool, subOnly bool, filler bool, recap bool) {
+	t.Helper()
+	if got.Number != number || got.Title != title || got.HasSub != sub || got.HasDub != dub || got.SubOnly != subOnly || got.Filler != filler || got.Recap != recap {
+		t.Fatalf("episode = %+v, want number=%d title=%q sub=%t dub=%t subOnly=%t filler=%t recap=%t", got, number, title, sub, dub, subOnly, filler, recap)
+	}
+}