internal product index

cmd/cart/projection_cache_test.go

@@ -146,6 +146,45 @@ func TestProjectionCache_BusRaceSafe(t *testing.T) {
 	}
 }
 
+// TestApply_MixedUpsertDelete verifies the realistic per-batch sequence a
+// publisher emits: a single Apply call interleaves upserts and deletes, and
+// the per-batch counters report the right split. Without this the cache could
+// drift on count semantics across batched events.
+func TestApply_MixedUpsertDelete(t *testing.T) {
+	c := newCatalogProjectionCache()
+	// Order matters: prior in-cache state for A is upserted twice (latest wins),
+	// B is tombstoned, C cold-upserted, D cold-tombstoned.
+	updates := []catalog.ProjectionUpdate{
+		{Projection: catalog.Projection{SKU: "A", PriceIncVat: money.Cents(50_00)}},
+		{Projection: catalog.Projection{SKU: "B"}, Deleted: true},
+		{Projection: catalog.Projection{SKU: "C", PriceIncVat: money.Cents(75_00)}},
+		{Projection: catalog.Projection{SKU: "A", PriceIncVat: money.Cents(60_00)}}, // later wins
+		{Projection: catalog.Projection{SKU: "D"}, Deleted: true},
+	}
+	upserts, deletes := c.Apply(updates)
+	if upserts != 3 || deletes != 2 {
+		t.Fatalf("counts: upserts=%d deletes=%d, want 3/2 (A,C live-upserts; B,D tombstones)", upserts, deletes)
+	}
+	if got, ok := c.Get("A"); !ok || got.PriceIncVat != money.Cents(60_00) {
+		t.Fatalf("A latest-wins: got %+v ok=%v, want 6000", got, ok)
+	}
+	if _, ok := c.Get("B"); ok {
+		t.Fatalf("B: tombstoned but Get returned a value")
+	}
+	if !c.IsDeleted("B") {
+		t.Fatalf("B: IsDeleted not true")
+	}
+	if got, ok := c.Get("C"); !ok || got.PriceIncVat != money.Cents(75_00) {
+		t.Fatalf("C cold-upsert: got %+v ok=%v, want 7500", got, ok)
+	}
+	if !c.IsDeleted("D") {
+		t.Fatalf("D: IsDeleted not true")
+	}
+	if c.Len() != 4 {
+		t.Fatalf("Len() after mixed batch: %d, want 4 (A live + B tombstone + C live + D tombstone)", c.Len())
+	}
+}
+
 // TestTaxResolveBp covers the static TaxClass→bp mapping used by
 // ApplyProjectionOverlay. Adds a regression net for the common Nordic rates.
 func TestTaxResolveBp(t *testing.T) {