product variant id

repositories/productVariantLink_test.go

@@ -0,0 +1,67 @@
+package repositories
+
+import (
+	"errors"
+	"testing"
+
+	"nearle/models"
+)
+
+/*
+Variants are a relationship between two products, and every test here is about
+a shape that would break the ordering screen rather than merely store bad data.
+
+The bug this replaces: `productvariants` had `productid` and `variantproductid`
+all along, neither was mapped, so a variant could never be attached to a
+product. The app fell back to `products.variants` — a group number that is 0 on
+every product — and asked for "everything in group 0", which matched the
+tenant's whole ungrouped catalogue. Six unrelated products came back as each
+other's sizes and the order could not be placed.
+*/
+
+func TestAVariantWithoutAParentIsRefused(t *testing.T) {
+	r := &productRepository{}
+	_, err := r.AddProductVariant(models.Productvariant{Tenantid: 1, Variantproductid: 7})
+	if !errors.Is(err, ErrVariantParentMissing) {
+		t.Fatalf("expected a missing-parent refusal, got %v", err)
+	}
+}
+
+func TestAVariantThatOrdersNothingIsRefused(t *testing.T) {
+	// Without `variantproductid` there is no product to put in the basket, so
+	// the size would be pickable and unbuyable.
+	r := &productRepository{}
+	_, err := r.AddProductVariant(models.Productvariant{Tenantid: 1, Productid: 7})
+	if !errors.Is(err, ErrVariantProductMissing) {
+		t.Fatalf("expected a missing-product refusal, got %v", err)
+	}
+}
+
+func TestAProductCannotBeItsOwnVariant(t *testing.T) {
+	// The picker would offer the thing already tapped, and choosing it loops.
+	r := &productRepository{}
+	_, err := r.AddProductVariant(models.Productvariant{Tenantid: 1, Productid: 7, Variantproductid: 7})
+	if !errors.Is(err, ErrVariantSelfReference) {
+		t.Fatalf("expected a self-reference refusal, got %v", err)
+	}
+}
+
+func TestNoProductsMeansNoQueryAndNoVariants(t *testing.T) {
+	// Guards the N+1: the batch loader must not run a query for an empty page.
+	// `r.db` is nil here, so reaching the database at all would panic.
+	r := &productRepository{}
+	got, err := r.VariantsForProducts(1, 1, nil)
+	if err != nil {
+		t.Fatalf("VariantsForProducts: %v", err)
+	}
+	if len(got) != 0 {
+		t.Errorf("expected no variants, got %d", len(got))
+	}
+}
+
+func TestAnUnknownTenantAsksTheDatabaseNothing(t *testing.T) {
+	r := &productRepository{}
+	if _, err := r.VariantsForProducts(0, 1, []int{7, 8}); err != nil {
+		t.Fatalf("VariantsForProducts: %v", err)
+	}
+}