variants as a single product

services/productVisibility_test.go

@@ -667,3 +667,51 @@ func TestFilteringGroupsDoesNotDisturbTheCallersSlice(t *testing.T) {
 		t.Errorf("the caller's slice was modified: %d products left", len(original[0].Products))
 	}
 }
+
+/*
+One product, three sizes.
+
+R mart stocks Aachi Baby Fryums as three product rows — 100g, 500g and 1kg —
+each with its own price and its own shelf. In the app that read as three
+near-identical listings a shopper had to tell apart by a suffix. Grouped, it is
+one listing with a size picker.
+*/
+
+func TestASizeOfAnotherProductIsNotListedOnItsOwn(t *testing.T) {
+	groups := []models.Tenantproducts{{Products: []models.Products{
+		{Productid: 7112}, // 100g — the parent
+		{Productid: 7113}, // 1kg  — a size of it
+		{Productid: 7114}, // 500g — a size of it
+	}}}
+	got := WithoutVariantChildren(groups, map[int]bool{7113: true, 7114: true})
+	if len(got[0].Products) != 1 || got[0].Products[0].Productid != 7112 {
+		t.Fatalf("expected only the parent, got %v", got[0].Products)
+	}
+}
+
+func TestAShopWithNoGroupsIsUntouched(t *testing.T) {
+	// The common case by far, and it must not pay for the feature.
+	groups := []models.Tenantproducts{{Products: []models.Products{{Productid: 1}, {Productid: 2}}}}
+	got := WithoutVariantChildren(groups, map[int]bool{})
+	if len(got[0].Products) != 2 {
+		t.Errorf("an ungrouped shop lost products: %v", got[0].Products)
+	}
+}
+
+func TestTheShopSurvivesEvenIfEveryProductIsASize(t *testing.T) {
+	// Should not happen — a group always has a parent — but a listing is the
+	// wrong place to discover bad data, and an empty list beats a crash.
+	groups := []models.Tenantproducts{{Products: []models.Products{{Productid: 5}}}}
+	got := WithoutVariantChildren(groups, map[int]bool{5: true})
+	if len(got) != 1 || len(got[0].Products) != 0 {
+		t.Errorf("expected the shop to survive with nothing listed, got %v", got)
+	}
+}
+
+func TestFilteringChildrenDoesNotDisturbTheCallersSlice(t *testing.T) {
+	original := []models.Tenantproducts{{Products: []models.Products{{Productid: 1}, {Productid: 2}}}}
+	_ = WithoutVariantChildren(original, map[int]bool{2: true})
+	if len(original[0].Products) != 2 {
+		t.Errorf("the caller's slice was modified")
+	}
+}