0.3.06

server/internal/recommend/explain_test.go

@@ -30,17 +30,17 @@ const thrillerHistory = `{
 	"People":[{"Name":"Denis Villeneuve","Type":"Director"},{"Name":"Emily Blunt","Type":"Actor"}]
 }`
 
-func TestWhyNamesTheGenreTheViewerActuallyWatches(t *testing.T) {
+func TestWhyPrefersTheRelatedTitleOverItsGenres(t *testing.T) {
 	profile := explainProfile(t, thrillerHistory)
 	candidate := explainItem(t, `{
-		"Id":"c1","Name":"Prisoners","Type":"Movie","Genres":["Thriller"],
+		"Id":"c1","Name":"Prisoners","Type":"Movie","Genres":["Thriller","Crime"],
 		"People":[{"Name":"Denis Villeneuve","Type":"Director"}]
 	}`)
 
 	reasons := Why(profile, candidate, ReasonLimit)
 
-	if len(reasons) == 0 || reasons[0] != "Because you watch Thriller" {
-		t.Fatalf("expected the genre reason first, got %v", reasons)
+	if len(reasons) == 0 || reasons[0] != "Because you watched Sicario" {
+		t.Fatalf("expected the related viewing reason first, got %v", reasons)
 	}
 	if !strings.Contains(strings.Join(reasons, "|"), "Denis Villeneuve") {
 		t.Fatalf("expected the shared director to be named, got %v", reasons)
@@ -73,7 +73,7 @@ func TestWhyAlwaysSaysSomething(t *testing.T) {
 
 	reasons := Why(Profile{}, candidate, ReasonLimit)
 
-	if len(reasons) != 1 || reasons[0] != "Drama from your library" {
+	if len(reasons) != 1 || reasons[0] != "Recommended from your library" {
 		t.Fatalf("an empty profile should still explain the title, got %v", reasons)
 	}
 }
@@ -98,9 +98,9 @@ func TestWhyIsCappedAndOrdered(t *testing.T) {
 		t.Fatalf("expected exactly %d reasons, got %v", ReasonLimit, reasons)
 	}
 	want := []string{
-		"Because you watch Thriller",
-		"You've watched Emily Blunt before",
-		"More from Lionsgate",
+		"Because you watched Sicario",
+		"Because you like crime thrillers",
+		"Because you watch Emily Blunt",
 	}
 	for i, reason := range want {
 		if reasons[i] != reason {
@@ -109,6 +109,103 @@ func TestWhyIsCappedAndOrdered(t *testing.T) {
 	}
 }
 
+func TestWhyDoesNotTreatDramaAloneAsATitleRelationship(t *testing.T) {
+	profile := explainProfile(t, `{
+		"Id":"h1","Name":"A Drama","Type":"Movie","Genres":["Drama"]
+	}`)
+	candidate := explainItem(t, `{
+		"Id":"c1","Name":"Another Drama","Type":"Movie","Genres":["Drama"]
+	}`)
+
+	reasons := Why(profile, candidate, ReasonLimit)
+
+	if reasons[0] != "Because you watch Drama" {
+		t.Fatalf("broad genre should be the fallback, got %v", reasons)
+	}
+	if strings.Contains(strings.Join(reasons, "|"), "A Drama") {
+		t.Fatalf("Drama alone invented a title relationship: %v", reasons)
+	}
+}
+
+func TestWhyUsesSpecificSubgenreBeforeBroadGenre(t *testing.T) {
+	profile := explainProfile(t, `{
+		"Id":"h1","Name":"Crime One","Type":"Movie","Genres":["Crime","Drama"]
+	}`)
+	// Do not retain title evidence here: this test isolates the learned theme wording.
+	profile.ReasonEvidence = nil
+	candidate := explainItem(t, `{
+		"Id":"c1","Name":"Crime Two","Type":"Series","Genres":["Drama","Crime"]
+	}`)
+
+	if got := Why(profile, candidate, 1); len(got) != 1 || got[0] != "Because you like crime dramas" {
+		t.Fatalf("specific theme reason = %v", got)
+	}
+}
+
+func TestWhyUsesCreatorBeforeBroadGenre(t *testing.T) {
+	profile := explainProfile(t, `{
+		"Id":"h1","Name":"The First","Type":"Movie","Genres":["Drama"],
+		"People":[{"Name":"Vince Gilligan","Type":"Writer"}]
+	}`)
+	candidate := explainItem(t, `{
+		"Id":"c1","Name":"The Second","Type":"Series","Genres":["Drama"],
+		"People":[{"Name":"Vince Gilligan","Type":"Writer"}]
+	}`)
+
+	if got := Why(profile, candidate, 1); len(got) != 1 || got[0] != "More from Vince Gilligan" {
+		t.Fatalf("creator reason = %v", got)
+	}
+}
+
+func TestWhyDistinguishesFinishedTitlesFromEpisodes(t *testing.T) {
+	finished := explainItem(t, `{
+		"Id":"h1","Name":"Breaking Bad","Type":"Series","Genres":["Crime","Drama"],
+		"UserData":{"Played":true}
+	}`)
+	candidate := explainItem(t, `{
+		"Id":"c1","Name":"Better Call Saul","Type":"Series","Genres":["Crime","Drama"]
+	}`)
+	if got := Why(BuildProfile([]Item{finished}, nil), candidate, 1); got[0] != "Because you finished Breaking Bad" {
+		t.Fatalf("completed title reason = %v", got)
+	}
+
+	episodeHistory := explainItem(t, `{
+		"Id":"ep1","Name":"Pilot","Type":"Episode","SeriesId":"show-1",
+		"SeriesName":"Breaking Bad","Genres":["Crime","Drama"],"UserData":{"Played":true}
+	}`)
+	if got := Why(BuildProfile([]Item{episodeHistory}, nil), candidate, 1); got[0] != "Because you watched Breaking Bad" {
+		t.Fatalf("completed episode overstated series completion: %v", got)
+	}
+}
+
+func TestWhyCanUseARepeatedViewingEra(t *testing.T) {
+	profile := explainProfile(t,
+		`{"Id":"h1","Name":"One","Type":"Movie","ProductionYear":2003,"Genres":["Drama"]}`,
+		`{"Id":"h2","Name":"Two","Type":"Movie","ProductionYear":2007,"Genres":["Drama"]}`,
+	)
+	profile.ReasonEvidence = nil
+	candidate := explainItem(t, `{
+		"Id":"c1","Name":"Three","Type":"Movie","ProductionYear":2005,"Genres":["Drama"]
+	}`)
+
+	if got := Why(profile, candidate, 1); got[0] != "Because you've been watching 2000s dramas" {
+		t.Fatalf("viewing-era reason = %v", got)
+	}
+}
+
+func TestWhyCanNameAFavouriteTitle(t *testing.T) {
+	favourite := explainItem(t, `{
+		"Id":"h1","Name":"The Wire","Type":"Series","Genres":["Crime","Drama"]
+	}`)
+	candidate := explainItem(t, `{
+		"Id":"c1","Name":"We Own This City","Type":"Series","Genres":["Crime","Drama"]
+	}`)
+
+	if got := Why(BuildProfile(nil, []Item{favourite}), candidate, 1); got[0] != "Because you like The Wire" {
+		t.Fatalf("favourite-title reason = %v", got)
+	}
+}
+
 func TestWhyIsStableAcrossCalls(t *testing.T) {
 	profile := explainProfile(t, thrillerHistory)
 	candidate := explainItem(t, `{