test: add recommendation scoring profile tests for weights, taste, and ranking

internal/anime/recommendations/scoring_profile_extra_test.go

@@ -0,0 +1,136 @@
+package recommendations
+
+import (
+	"math"
+	"testing"
+	"time"
+
+	"mal/integrations/jikan"
+)
+
+func TestProfileSearchRankWeightHasFloor(t *testing.T) {
+	if got := profileSearchRankWeight(0); got != 1 {
+		t.Fatalf("rank 0 weight = %f, want 1", got)
+	}
+	if got := profileSearchRankWeight(100); got != 0.35 {
+		t.Fatalf("rank 100 weight = %f, want floor 0.35", got)
+	}
+}
+
+func TestRankedCandidateRetrievalScoreUsesLogForCollaborativeSignal(t *testing.T) {
+	low := rankedCandidateRetrievalScore(1, 0)
+	high := rankedCandidateRetrievalScore(100, 0)
+	if high <= low {
+		t.Fatalf("expected higher collaborative score to rank higher, low=%f high=%f", low, high)
+	}
+	linearGrowth := 100.0 - 1.0
+	actualGrowth := high - low
+	if actualGrowth >= linearGrowth {
+		t.Fatalf("expected log scaling, growth=%f linear=%f", actualGrowth, linearGrowth)
+	}
+}
+
+func TestHasTasteMetadata(t *testing.T) {
+	if hasTasteMetadata(jikan.Anime{}) {
+		t.Fatalf("empty anime should not have taste metadata")
+	}
+	if !hasTasteMetadata(jikan.Anime{Studios: []jikan.NamedEntity{{MalID: 1}}}) {
+		t.Fatalf("studio metadata should count as taste metadata")
+	}
+}
+
+func TestRecommendationCandidateScoreAdjustments(t *testing.T) {
+	now := time.Date(2026, time.June, 4, 12, 0, 0, 0, time.UTC)
+	profile := userTasteProfile{prefersAiring: true, prefersRecent: true}
+
+	preferred := recommendationCandidateScoreAdjustments(now, profile, jikan.Anime{
+		Score:      9,
+		Popularity: 10,
+		Airing:     true,
+		Year:       2026,
+		Aired:      jikan.Aired{From: now.Add(-24 * time.Hour).Format(time.RFC3339)},
+	})
+	penalized := recommendationCandidateScoreAdjustments(now, profile, jikan.Anime{
+		Score:  9,
+		Year:   2000,
+		Status: "Not yet aired",
+	})
+
+	if preferred <= penalized {
+		t.Fatalf("expected preferred candidate to outscore penalized candidate, preferred=%f penalized=%f", preferred, penalized)
+	}
+	if !isRecentCandidate(now, 2024) || isRecentCandidate(now, 2010) {
+		t.Fatalf("recent candidate boundary failed")
+	}
+	if !isClassicCandidate(now, 2010) || isClassicCandidate(now, 2020) {
+		t.Fatalf("classic candidate boundary failed")
+	}
+	if !isFreshRelease(now, now.Add(-freshReleaseWindow+time.Hour).Format(time.RFC3339)) {
+		t.Fatalf("expected fresh release inside window")
+	}
+	if isFreshRelease(now, "not a date") {
+		t.Fatalf("invalid release timestamp should not be fresh")
+	}
+}
+
+func TestWeightedEntityMatchCountsAndScoresMatches(t *testing.T) {
+	matches, score := weightedEntityMatch(map[int]float64{1: 2.5, 3: 1.0}, []jikan.NamedEntity{
+		{MalID: 1, Name: "Action"},
+		{MalID: 2, Name: "Drama"},
+		{MalID: 3, Name: "Sports"},
+	})
+
+	if matches != 2 || score != 3.5 {
+		t.Fatalf("weightedEntityMatch = matches:%d score:%f, want 2 and 3.5", matches, score)
+	}
+}
+
+func TestAddEntityWeightsSkipsInvalidIDsAndAccumulates(t *testing.T) {
+	target := map[int]float64{1: 1.0}
+	addEntityWeights(target, []jikan.NamedEntity{{MalID: 0}, {MalID: 1}, {MalID: 2}}, 0.5)
+
+	if target[1] != 1.5 || target[2] != 0.5 {
+		t.Fatalf("entity weights = %#v, want accumulated valid ids", target)
+	}
+	if _, ok := target[0]; ok {
+		t.Fatalf("invalid id should not be added: %#v", target)
+	}
+}
+
+func TestStrongestWeightedEntitiesSortsByWeightThenID(t *testing.T) {
+	got := strongestWeightedEntities(map[int]float64{3: 1, 2: 2, 1: 2, 4: -1}, 3)
+	want := []weightedEntity{{id: 1, weight: 2}, {id: 2, weight: 2}, {id: 3, weight: 1}}
+
+	if len(got) != len(want) {
+		t.Fatalf("len(got) = %d, want %d", len(got), len(want))
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("got[%d] = %+v, want %+v", i, got[i], want[i])
+		}
+	}
+}
+
+func TestScoreRecommendationCandidateIncludesMatchCounts(t *testing.T) {
+	now := time.Date(2026, time.June, 4, 12, 0, 0, 0, time.UTC)
+	profile := userTasteProfile{
+		genres:       map[int]float64{1: 1, 2: 1},
+		themes:       map[int]float64{10: 1},
+		studios:      map[int]float64{20: 1},
+		demographics: map[int]float64{30: 1},
+	}
+
+	candidate := scoreRecommendationCandidate(now, profile, jikan.Anime{
+		Genres:       []jikan.NamedEntity{{MalID: 1}, {MalID: 2}},
+		Themes:       []jikan.NamedEntity{{MalID: 10}},
+		Studios:      []jikan.NamedEntity{{MalID: 20}},
+		Demographics: []jikan.NamedEntity{{MalID: 30}},
+	}, 0, 0)
+
+	if candidate.genreMatches != 2 || candidate.themeMatches != 1 || candidate.studioMatches != 1 || candidate.demographicMatches != 1 {
+		t.Fatalf("match counts = genres:%d themes:%d studios:%d demos:%d", candidate.genreMatches, candidate.themeMatches, candidate.studioMatches, candidate.demographicMatches)
+	}
+	if math.Abs(candidate.score) < 0.001 {
+		t.Fatalf("expected non-zero score for metadata matches")
+	}
+}